postconf.5.html revision 1.8.4.1
1 <!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN" 2 "http://www.w3.org/TR/html4/loose.dtd"> 3 4 <html> 5 6 <head> 7 8 <title>Postfix Configuration Parameters </title> 9 10 <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> 11 12 </head> 13 14 <body> 15 16 <h1><img src="postfix-logo.jpg" width="203" height="98" alt="">Postfix Configuration Parameters </h1> 17 18 <hr> 19 20 <h2> Postfix main.cf file format </h2> 21 22 <p> The Postfix main.cf configuration file specifies a very small 23 subset of all the parameters that control the operation of the 24 Postfix mail system. Parameters not explicitly specified are left 25 at their default values. </p> 26 27 <p> The general format of the main.cf file is as follows: </p> 28 29 <ul> 30 31 <li> <p> Each logical line is in the form "parameter = value". 32 Whitespace around the "=" is ignored, as is whitespace at the end 33 of a logical line. </p> 34 35 <li> <p> Empty lines and whitespace-only lines are ignored, as are 36 lines whose first non-whitespace character is a `#'. </p> 37 38 <li> <p> A logical line starts with non-whitespace text. A line 39 that starts with whitespace continues a logical line. </p> 40 41 <li> <p> A parameter value may refer to other parameters. </p> 42 43 <ul> 44 45 <li> <p> The expressions "$name", "${name}" or "$(name)" are 46 recursively replaced by the value of the named parameter. </p> 47 48 <li> <p> The expression "${name?value}" expands to "value" when 49 "$name" is non-empty. This form is supported with Postfix version 50 2.2 and later. </p> 51 52 <li> <p> The expression "${name:value}" expands to "value" when 53 "$name" is empty. This form is supported with Postfix version 2.2 54 and later. </p> 55 56 <li> <p> Specify "$$" to produce a single "$" character. </p> 57 58 </ul> 59 60 <li> <p> When the same parameter is defined multiple times, only 61 the last instance is remembered. </p> 62 63 <li> <p> Otherwise, the order of main.cf parameter definitions does 64 not matter. </p> 65 66 </ul> 67 68 <p> The remainder of this document is a description of all Postfix 69 configuration parameters. Default values are shown after the 70 parameter name in parentheses, and can be looked up with the 71 "<b>postconf -d</b>" command. </p> 72 73 <p> Note: this is not an invitation to make changes to Postfix 74 configuration parameters. Unnecessary changes are likely to impair 75 the operation of the mail system. </p> 76 77 <dl> 78 <DT><b><a name="2bounce_notice_recipient">2bounce_notice_recipient</a> 79 (default: postmaster)</b></DT><DD> 80 81 <p> The recipient of undeliverable mail that cannot be returned to 82 the sender. This feature is enabled with the <a href="postconf.5.html#notify_classes">notify_classes</a> 83 parameter. </p> 84 85 86 </DD> 87 88 <DT><b><a name="access_map_defer_code">access_map_defer_code</a> 89 (default: 450)</b></DT><DD> 90 91 <p> 92 The numerical Postfix SMTP server response code for 93 an <a href="access.5.html">access(5)</a> map "defer" action, including "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" 94 or "<a href="postconf.5.html#defer_if_reject">defer_if_reject</a>". Prior to Postfix 2.6, the response 95 is hard-coded as "450". 96 </p> 97 98 <p> 99 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 100 </p> 101 102 <p> 103 This feature is available in Postfix 2.6 and later. 104 </p> 105 106 107 </DD> 108 109 <DT><b><a name="access_map_reject_code">access_map_reject_code</a> 110 (default: 554)</b></DT><DD> 111 112 <p> 113 The numerical Postfix SMTP server response code for 114 an <a href="access.5.html">access(5)</a> map "reject" action. 115 </p> 116 117 <p> 118 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 119 </p> 120 121 122 </DD> 123 124 <DT><b><a name="address_verify_cache_cleanup_interval">address_verify_cache_cleanup_interval</a> 125 (default: 12h)</b></DT><DD> 126 127 <p> The amount of time between <a href="verify.8.html">verify(8)</a> address verification 128 database cleanup runs. This feature requires that the database 129 supports the "delete" and "sequence" operators. Specify a zero 130 interval to disable database cleanup. </p> 131 132 <p> After each database cleanup run, the <a href="verify.8.html">verify(8)</a> daemon logs the 133 number of entries that were retained and dropped. A cleanup run is 134 logged as "partial" when the daemon terminates early after "<b>postfix 135 reload</b>", "<b>postfix stop</b>", or no requests for $<a href="postconf.5.html#max_idle">max_idle</a> 136 seconds. </p> 137 138 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 139 (weeks). </p> 140 141 <p> This feature is available in Postfix 2.7. </p> 142 143 144 </DD> 145 146 <DT><b><a name="address_verify_default_transport">address_verify_default_transport</a> 147 (default: $<a href="postconf.5.html#default_transport">default_transport</a>)</b></DT><DD> 148 149 <p> 150 Overrides the <a href="postconf.5.html#default_transport">default_transport</a> parameter setting for address 151 verification probes. 152 </p> 153 154 <p> 155 This feature is available in Postfix 2.1 and later. 156 </p> 157 158 159 </DD> 160 161 <DT><b><a name="address_verify_local_transport">address_verify_local_transport</a> 162 (default: $<a href="postconf.5.html#local_transport">local_transport</a>)</b></DT><DD> 163 164 <p> 165 Overrides the <a href="postconf.5.html#local_transport">local_transport</a> parameter setting for address 166 verification probes. 167 </p> 168 169 <p> 170 This feature is available in Postfix 2.1 and later. 171 </p> 172 173 174 </DD> 175 176 <DT><b><a name="address_verify_map">address_verify_map</a> 177 (default: see "postconf -d" output)</b></DT><DD> 178 179 <p> 180 Lookup table for persistent address verification status 181 storage. The table is maintained by the <a href="verify.8.html">verify(8)</a> service, and 182 is opened before the process releases privileges. 183 </p> 184 185 <p> 186 The lookup table is persistent by default (Postfix 2.7 and later). 187 Specify an empty table name to keep the information in volatile 188 memory which is lost after "<b>postfix reload</b>" or "<b>postfix 189 stop</b>". This is the default with Postfix version 2.6 and earlier. 190 </p> 191 192 <p> 193 Specify a location in a file system that will not fill up. If the 194 database becomes corrupted, the world comes to an end. To recover 195 delete (NOT: truncate) the file and do "<b>postfix reload</b>". 196 </p> 197 198 <p> Postfix daemon processes do not use root privileges when opening 199 this file (Postfix 2.5 and later). The file must therefore be 200 stored under a Postfix-owned directory such as the <a href="postconf.5.html#data_directory">data_directory</a>. 201 As a migration aid, an attempt to open the file under a non-Postfix 202 directory is redirected to the Postfix-owned <a href="postconf.5.html#data_directory">data_directory</a>, and a 203 warning is logged. </p> 204 205 <p> 206 Examples: 207 </p> 208 209 <pre> 210 <a href="postconf.5.html#address_verify_map">address_verify_map</a> = hash:/var/db/postfix/verify 211 <a href="postconf.5.html#address_verify_map">address_verify_map</a> = btree:/var/db/postfix/verify 212 </pre> 213 214 <p> 215 This feature is available in Postfix 2.1 and later. 216 </p> 217 218 219 </DD> 220 221 <DT><b><a name="address_verify_negative_cache">address_verify_negative_cache</a> 222 (default: yes)</b></DT><DD> 223 224 <p> 225 Enable caching of failed address verification probe results. When 226 this feature is enabled, the cache may pollute quickly with garbage. 227 When this feature is disabled, Postfix will generate an address 228 probe for every lookup. 229 </p> 230 231 <p> 232 This feature is available in Postfix 2.1 and later. 233 </p> 234 235 236 </DD> 237 238 <DT><b><a name="address_verify_negative_expire_time">address_verify_negative_expire_time</a> 239 (default: 3d)</b></DT><DD> 240 241 <p> 242 The time after which a failed probe expires from the address 243 verification cache. 244 </p> 245 246 <p> 247 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 248 </p> 249 250 <p> 251 This feature is available in Postfix 2.1 and later. 252 </p> 253 254 255 </DD> 256 257 <DT><b><a name="address_verify_negative_refresh_time">address_verify_negative_refresh_time</a> 258 (default: 3h)</b></DT><DD> 259 260 <p> 261 The time after which a failed address verification probe needs to 262 be refreshed. 263 </p> 264 265 <p> 266 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 267 </p> 268 269 <p> 270 This feature is available in Postfix 2.1 and later. 271 </p> 272 273 274 </DD> 275 276 <DT><b><a name="address_verify_poll_count">address_verify_poll_count</a> 277 (default: normal: 3, overload: 1)</b></DT><DD> 278 279 <p> 280 How many times to query the <a href="verify.8.html">verify(8)</a> service for the completion 281 of an address verification request in progress. 282 </p> 283 284 <p> By default, the Postfix SMTP server polls the <a href="verify.8.html">verify(8)</a> service 285 up to three times under non-overload conditions, and only once when 286 under overload. With Postfix version 2.5 and earlier, the SMTP 287 server always polls the <a href="verify.8.html">verify(8)</a> service up to three times by 288 default. </p> 289 290 <p> 291 Specify 1 to implement a crude form of greylisting, that is, always 292 defer the first delivery request for a new address. 293 </p> 294 295 <p> 296 Examples: 297 </p> 298 299 <pre> 300 # Postfix ≤ 2.6 default 301 <a href="postconf.5.html#address_verify_poll_count">address_verify_poll_count</a> = 3 302 # Poor man's greylisting 303 <a href="postconf.5.html#address_verify_poll_count">address_verify_poll_count</a> = 1 304 </pre> 305 306 <p> 307 This feature is available in Postfix 2.1 and later. 308 </p> 309 310 311 </DD> 312 313 <DT><b><a name="address_verify_poll_delay">address_verify_poll_delay</a> 314 (default: 3s)</b></DT><DD> 315 316 <p> 317 The delay between queries for the completion of an address 318 verification request in progress. 319 </p> 320 321 <p> 322 The default polling delay is 3 seconds. 323 </p> 324 325 <p> 326 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 327 </p> 328 329 <p> 330 This feature is available in Postfix 2.1 and later. 331 </p> 332 333 334 </DD> 335 336 <DT><b><a name="address_verify_positive_expire_time">address_verify_positive_expire_time</a> 337 (default: 31d)</b></DT><DD> 338 339 <p> 340 The time after which a successful probe expires from the address 341 verification cache. 342 </p> 343 344 <p> 345 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 346 </p> 347 348 <p> 349 This feature is available in Postfix 2.1 and later. 350 </p> 351 352 353 </DD> 354 355 <DT><b><a name="address_verify_positive_refresh_time">address_verify_positive_refresh_time</a> 356 (default: 7d)</b></DT><DD> 357 358 <p> 359 The time after which a successful address verification probe needs 360 to be refreshed. The address verification status is not updated 361 when the probe fails (optimistic caching). 362 </p> 363 364 <p> 365 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 366 </p> 367 368 <p> 369 This feature is available in Postfix 2.1 and later. 370 </p> 371 372 373 </DD> 374 375 <DT><b><a name="address_verify_relay_transport">address_verify_relay_transport</a> 376 (default: $<a href="postconf.5.html#relay_transport">relay_transport</a>)</b></DT><DD> 377 378 <p> 379 Overrides the <a href="postconf.5.html#relay_transport">relay_transport</a> parameter setting for address 380 verification probes. 381 </p> 382 383 <p> 384 This feature is available in Postfix 2.1 and later. 385 </p> 386 387 388 </DD> 389 390 <DT><b><a name="address_verify_relayhost">address_verify_relayhost</a> 391 (default: $<a href="postconf.5.html#relayhost">relayhost</a>)</b></DT><DD> 392 393 <p> 394 Overrides the <a href="postconf.5.html#relayhost">relayhost</a> parameter setting for address verification 395 probes. This information can be overruled with the <a href="transport.5.html">transport(5)</a> table. 396 </p> 397 398 <p> 399 This feature is available in Postfix 2.1 and later. 400 </p> 401 402 403 </DD> 404 405 <DT><b><a name="address_verify_sender">address_verify_sender</a> 406 (default: $<a href="postconf.5.html#double_bounce_sender">double_bounce_sender</a>)</b></DT><DD> 407 408 <p> The sender address to use in address verification probes; prior 409 to Postfix 2.5 the default was "postmaster". To 410 avoid problems with address probes that are sent in response to 411 address probes, the Postfix SMTP server excludes the probe sender 412 address from all SMTPD access blocks. </p> 413 414 <p> 415 Specify an empty value (<a href="postconf.5.html#address_verify_sender">address_verify_sender</a> =) or <> if you want 416 to use the null sender address. Beware, some sites reject mail from 417 <>, even though RFCs require that such addresses be accepted. 418 </p> 419 420 <p> 421 Examples: 422 </p> 423 424 <pre> 425 <a href="postconf.5.html#address_verify_sender">address_verify_sender</a> = <> 426 <a href="postconf.5.html#address_verify_sender">address_verify_sender</a> = postmaster (a] my.domain 427 </pre> 428 429 <p> 430 This feature is available in Postfix 2.1 and later. 431 </p> 432 433 434 </DD> 435 436 <DT><b><a name="address_verify_sender_dependent_default_transport_maps">address_verify_sender_dependent_default_transport_maps</a> 437 (default: $<a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a>)</b></DT><DD> 438 439 <p> Overrides the <a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a> parameter 440 setting for address verification probes. </p> 441 442 <p> This feature is available in Postfix 2.7 and later. </p> 443 444 445 </DD> 446 447 <DT><b><a name="address_verify_sender_dependent_relayhost_maps">address_verify_sender_dependent_relayhost_maps</a> 448 (default: $<a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>)</b></DT><DD> 449 450 <p> 451 Overrides the <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> parameter setting for address 452 verification probes. 453 </p> 454 455 <p> 456 This feature is available in Postfix 2.3 and later. 457 </p> 458 459 460 </DD> 461 462 <DT><b><a name="address_verify_service_name">address_verify_service_name</a> 463 (default: verify)</b></DT><DD> 464 465 <p> 466 The name of the <a href="verify.8.html">verify(8)</a> address verification service. This service 467 maintains the status of sender and/or recipient address verification 468 probes, and generates probes on request by other Postfix processes. 469 </p> 470 471 472 </DD> 473 474 <DT><b><a name="address_verify_transport_maps">address_verify_transport_maps</a> 475 (default: $<a href="postconf.5.html#transport_maps">transport_maps</a>)</b></DT><DD> 476 477 <p> 478 Overrides the <a href="postconf.5.html#transport_maps">transport_maps</a> parameter setting for address verification 479 probes. 480 </p> 481 482 <p> 483 This feature is available in Postfix 2.1 and later. 484 </p> 485 486 487 </DD> 488 489 <DT><b><a name="address_verify_virtual_transport">address_verify_virtual_transport</a> 490 (default: $<a href="postconf.5.html#virtual_transport">virtual_transport</a>)</b></DT><DD> 491 492 <p> 493 Overrides the <a href="postconf.5.html#virtual_transport">virtual_transport</a> parameter setting for address 494 verification probes. 495 </p> 496 497 <p> 498 This feature is available in Postfix 2.1 and later. 499 </p> 500 501 502 </DD> 503 504 <DT><b><a name="alias_database">alias_database</a> 505 (default: see "postconf -d" output)</b></DT><DD> 506 507 <p> 508 The alias databases for <a href="local.8.html">local(8)</a> delivery that are updated with 509 "<b>newaliases</b>" or with "<b>sendmail -bi</b>". 510 </p> 511 512 <p> 513 This is a separate configuration parameter because not all the 514 tables specified with $<a href="postconf.5.html#alias_maps">alias_maps</a> have to be local files. 515 </p> 516 517 <p> 518 Examples: 519 </p> 520 521 <pre> 522 <a href="postconf.5.html#alias_database">alias_database</a> = hash:/etc/aliases 523 <a href="postconf.5.html#alias_database">alias_database</a> = hash:/etc/mail/aliases 524 </pre> 525 526 527 </DD> 528 529 <DT><b><a name="alias_maps">alias_maps</a> 530 (default: see "postconf -d" output)</b></DT><DD> 531 532 <p> 533 The alias databases that are used for <a href="local.8.html">local(8)</a> delivery. See 534 <a href="aliases.5.html">aliases(5)</a> for syntax details. 535 </p> 536 537 <p> 538 The default list is system dependent. On systems with NIS, the 539 default is to search the local alias database, then the NIS alias 540 database. 541 </p> 542 543 <p> 544 If you change the alias database, run "<b>postalias /etc/aliases</b>" 545 (or wherever your system stores the mail alias file), or simply 546 run "<b>newaliases</b>" to build the necessary DBM or DB file. 547 </p> 548 549 <p> 550 The <a href="local.8.html">local(8)</a> delivery agent disallows regular expression substitution 551 of $1 etc. in <a href="postconf.5.html#alias_maps">alias_maps</a>, because that would open a security hole. 552 </p> 553 554 <p> 555 The <a href="local.8.html">local(8)</a> delivery agent will silently ignore requests to use 556 the <a href="proxymap.8.html">proxymap(8)</a> server within <a href="postconf.5.html#alias_maps">alias_maps</a>. Instead it will open the 557 table directly. Before Postfix version 2.2, the <a href="local.8.html">local(8)</a> delivery 558 agent will terminate with a fatal error. 559 </p> 560 561 <p> 562 Examples: 563 </p> 564 565 <pre> 566 <a href="postconf.5.html#alias_maps">alias_maps</a> = hash:/etc/aliases, nis:mail.aliases 567 <a href="postconf.5.html#alias_maps">alias_maps</a> = hash:/etc/aliases 568 </pre> 569 570 571 </DD> 572 573 <DT><b><a name="allow_mail_to_commands">allow_mail_to_commands</a> 574 (default: alias, forward)</b></DT><DD> 575 576 <p> 577 Restrict <a href="local.8.html">local(8)</a> mail delivery to external commands. The default 578 is to disallow delivery to "|command" in :include: files (see 579 <a href="aliases.5.html">aliases(5)</a> for the text that defines this terminology). 580 </p> 581 582 <p> 583 Specify zero or more of: <b>alias</b>, <b>forward</b> or <b>include</b>, 584 in order to allow commands in <a href="aliases.5.html">aliases(5)</a>, .forward files or in 585 :include: files, respectively. 586 </p> 587 588 <p> 589 Example: 590 </p> 591 592 <pre> 593 <a href="postconf.5.html#allow_mail_to_commands">allow_mail_to_commands</a> = alias,forward,include 594 </pre> 595 596 597 </DD> 598 599 <DT><b><a name="allow_mail_to_files">allow_mail_to_files</a> 600 (default: alias, forward)</b></DT><DD> 601 602 <p> 603 Restrict <a href="local.8.html">local(8)</a> mail delivery to external files. The default is 604 to disallow "/file/name" destinations in :include: files (see 605 <a href="aliases.5.html">aliases(5)</a> for the text that defines this terminology). 606 </p> 607 608 <p> 609 Specify zero or more of: <b>alias</b>, <b>forward</b> or <b>include</b>, 610 in order to allow "/file/name" destinations in <a href="aliases.5.html">aliases(5)</a>, .forward 611 files and in :include: files, respectively. 612 </p> 613 614 <p> 615 Example: 616 </p> 617 618 <pre> 619 <a href="postconf.5.html#allow_mail_to_files">allow_mail_to_files</a> = alias,forward,include 620 </pre> 621 622 623 </DD> 624 625 <DT><b><a name="allow_min_user">allow_min_user</a> 626 (default: no)</b></DT><DD> 627 628 <p> 629 Allow a sender or recipient address to have `-' as the first 630 character. By 631 default, this is not allowed, to avoid accidents with software that 632 passes email addresses via the command line. Such software 633 would not be able to distinguish a malicious address from a 634 bona fide command-line option. Although this can be prevented by 635 inserting a "--" option terminator into the command line, this is 636 difficult to enforce consistently and globally. </p> 637 638 <p> As of Postfix version 2.5, this feature is implemented by 639 <a href="trivial-rewrite.8.html">trivial-rewrite(8)</a>. With earlier versions this feature was implemented 640 by <a href="qmgr.8.html">qmgr(8)</a> and was limited to recipient addresses only. </p> 641 642 643 </DD> 644 645 <DT><b><a name="allow_percent_hack">allow_percent_hack</a> 646 (default: yes)</b></DT><DD> 647 648 <p> 649 Enable the rewriting of the form "user%domain" to "user@domain". 650 This is enabled by default. 651 </p> 652 653 <p> Note: with Postfix version 2.2, message header address rewriting 654 happens only when one of the following conditions is true: </p> 655 656 <ul> 657 658 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 659 660 <li> The message is received from a network client that matches 661 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 662 663 <li> The message is received from the network, and the 664 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 665 666 </ul> 667 668 <p> To get the behavior before Postfix version 2.2, specify 669 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 670 671 <p> 672 Example: 673 </p> 674 675 <pre> 676 <a href="postconf.5.html#allow_percent_hack">allow_percent_hack</a> = no 677 </pre> 678 679 680 </DD> 681 682 <DT><b><a name="allow_untrusted_routing">allow_untrusted_routing</a> 683 (default: no)</b></DT><DD> 684 685 <p> 686 Forward mail with sender-specified routing (user[@%!]remote[@%!]site) 687 from untrusted clients to destinations matching $<a href="postconf.5.html#relay_domains">relay_domains</a>. 688 </p> 689 690 <p> 691 By default, this feature is turned off. This closes a nasty open 692 relay loophole where a backup MX host can be tricked into forwarding 693 junk mail to a primary MX host which then spams it out to the world. 694 </p> 695 696 <p> 697 This parameter also controls if non-local addresses with sender-specified 698 routing can match Postfix access tables. By default, such addresses 699 cannot match Postfix access tables, because the address is ambiguous. 700 </p> 701 702 703 </DD> 704 705 <DT><b><a name="alternate_config_directories">alternate_config_directories</a> 706 (default: empty)</b></DT><DD> 707 708 <p> 709 A list of non-default Postfix configuration directories that may 710 be specified with "-c <a href="postconf.5.html#config_directory">config_directory</a>" on the command line, or 711 via the MAIL_CONFIG environment parameter. 712 </p> 713 714 <p> 715 This list must be specified in the default Postfix configuration 716 directory, and is used by set-gid Postfix commands such as <a href="postqueue.1.html">postqueue(1)</a> 717 and <a href="postdrop.1.html">postdrop(1)</a>. 718 </p> 719 720 721 </DD> 722 723 <DT><b><a name="always_add_missing_headers">always_add_missing_headers</a> 724 (default: no)</b></DT><DD> 725 726 <p> Always add (Resent-) From:, To:, Date: or Message-ID: headers 727 when not present. Postfix 2.6 and later add these headers only 728 when clients match the <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> parameter 729 setting. Earlier Postfix versions always add these headers; this 730 may break DKIM signatures that cover non-existent headers. </p> 731 732 733 </DD> 734 735 <DT><b><a name="always_bcc">always_bcc</a> 736 (default: empty)</b></DT><DD> 737 738 <p> 739 Optional address that receives a "blind carbon copy" of each message 740 that is received by the Postfix mail system. 741 </p> 742 743 <p> 744 Note: if mail to the BCC address bounces it will be returned to 745 the sender. 746 </p> 747 748 <p> Note: automatic BCC recipients are produced only for new mail. 749 To avoid mailer loops, automatic BCC recipients are not generated 750 after Postfix forwards mail internally, or after Postfix generates 751 mail itself. </p> 752 753 754 </DD> 755 756 <DT><b><a name="anvil_rate_time_unit">anvil_rate_time_unit</a> 757 (default: 60s)</b></DT><DD> 758 759 <p> 760 The time unit over which client connection rates and other rates 761 are calculated. 762 </p> 763 764 <p> 765 This feature is implemented by the <a href="anvil.8.html">anvil(8)</a> service which is available 766 in Postfix version 2.2 and later. 767 </p> 768 769 <p> 770 The default interval is relatively short. Because of the high 771 frequency of updates, the <a href="anvil.8.html">anvil(8)</a> server uses volatile memory 772 only. Thus, information is lost whenever the process terminates. 773 </p> 774 775 <p> 776 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 777 The default time unit is s (seconds). 778 </p> 779 780 781 </DD> 782 783 <DT><b><a name="anvil_status_update_time">anvil_status_update_time</a> 784 (default: 600s)</b></DT><DD> 785 786 <p> 787 How frequently the <a href="anvil.8.html">anvil(8)</a> connection and rate limiting server 788 logs peak usage information. 789 </p> 790 791 <p> 792 This feature is available in Postfix 2.2 and later. 793 </p> 794 795 <p> 796 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 797 The default time unit is s (seconds). 798 </p> 799 800 801 </DD> 802 803 <DT><b><a name="append_at_myorigin">append_at_myorigin</a> 804 (default: yes)</b></DT><DD> 805 806 <p> 807 With locally submitted mail, append the string "@$<a href="postconf.5.html#myorigin">myorigin</a>" to mail 808 addresses without domain information. With remotely submitted mail, 809 append the string "@$<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a>" instead. 810 </p> 811 812 <p> 813 Note 1: this feature is enabled by default and must not be turned off. 814 Postfix does not support domain-less addresses. 815 </p> 816 817 <p> Note 2: with Postfix version 2.2, message header address rewriting 818 happens only when one of the following conditions is true: </p> 819 820 <ul> 821 822 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 823 824 <li> The message is received from a network client that matches 825 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 826 827 <li> The message is received from the network, and the 828 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 829 830 </ul> 831 832 <p> To get the behavior before Postfix version 2.2, specify 833 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 834 835 836 </DD> 837 838 <DT><b><a name="append_dot_mydomain">append_dot_mydomain</a> 839 (default: yes)</b></DT><DD> 840 841 <p> 842 With locally submitted mail, append the string ".$<a href="postconf.5.html#mydomain">mydomain</a>" to 843 addresses that have no ".domain" information. With remotely submitted 844 mail, append the string ".$<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a>" 845 instead. 846 </p> 847 848 <p> 849 Note 1: this feature is enabled by default. If disabled, users will not be 850 able to send mail to "user@partialdomainname" but will have to 851 specify full domain names instead. 852 </p> 853 854 <p> Note 2: with Postfix version 2.2, message header address rewriting 855 happens only when one of the following conditions is true: </p> 856 857 <ul> 858 859 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 860 861 <li> The message is received from a network client that matches 862 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 863 864 <li> The message is received from the network, and the 865 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 866 867 </ul> 868 869 <p> To get the behavior before Postfix version 2.2, specify 870 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 871 872 873 </DD> 874 875 <DT><b><a name="application_event_drain_time">application_event_drain_time</a> 876 (default: 100s)</b></DT><DD> 877 878 <p> 879 How long the <a href="postkick.1.html">postkick(1)</a> command waits for a request to enter the 880 server's input buffer before giving up. 881 </p> 882 883 <p> 884 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 885 The default time unit is s (seconds). 886 </p> 887 888 <p> 889 This feature is available in Postfix 2.1 and later. 890 </p> 891 892 893 </DD> 894 895 <DT><b><a name="authorized_flush_users">authorized_flush_users</a> 896 (default: static:anyone)</b></DT><DD> 897 898 <p> 899 List of users who are authorized to flush the queue. 900 </p> 901 902 <p> 903 By default, all users are allowed to flush the queue. Access is 904 always granted if the invoking user is the super-user or the 905 $<a href="postconf.5.html#mail_owner">mail_owner</a> user. Otherwise, the real UID of the process is looked 906 up in the system password file, and access is granted only if the 907 corresponding login name is on the access list. The username 908 "unknown" is used for processes whose real UID is not found in the 909 password file. </p> 910 911 <p> 912 Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns, 913 separated by commas and/or whitespace. The list is matched left to 914 right, and the search stops on the first match. A "/file/name" 915 pattern is replaced 916 by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name 917 matches a lookup key (the lookup result is ignored). Continue long 918 lines by starting the next line with whitespace. Specify "!pattern" 919 to exclude a name from the list. The form "!/file/name" is supported 920 only in Postfix version 2.4 and later. </p> 921 922 <p> 923 This feature is available in Postfix 2.2 and later. 924 </p> 925 926 927 </DD> 928 929 <DT><b><a name="authorized_mailq_users">authorized_mailq_users</a> 930 (default: static:anyone)</b></DT><DD> 931 932 <p> 933 List of users who are authorized to view the queue. 934 </p> 935 936 <p> 937 By default, all users are allowed to view the queue. Access is 938 always granted if the invoking user is the super-user or the 939 $<a href="postconf.5.html#mail_owner">mail_owner</a> user. Otherwise, the real UID of the process is looked 940 up in the system password file, and access is granted only if the 941 corresponding login name is on the access list. The username 942 "unknown" is used for processes whose real UID is not found in the 943 password file. </p> 944 945 <p> 946 Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns, 947 separated by commas and/or whitespace. The list is matched left to 948 right, and the search stops on the first match. A "/file/name" 949 pattern is replaced 950 by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name 951 matches a lookup key (the lookup result is ignored). Continue long 952 lines by starting the next line with whitespace. Specify "!pattern" 953 to exclude a user name from the list. The form "!/file/name" is 954 supported only in Postfix version 2.4 and later. </p> 955 956 <p> 957 This feature is available in Postfix 2.2 and later. 958 </p> 959 960 961 </DD> 962 963 <DT><b><a name="authorized_submit_users">authorized_submit_users</a> 964 (default: static:anyone)</b></DT><DD> 965 966 <p> 967 List of users who are authorized to submit mail with the <a href="sendmail.1.html">sendmail(1)</a> 968 command (and with the privileged <a href="postdrop.1.html">postdrop(1)</a> helper command). 969 </p> 970 971 <p> 972 By default, all users are allowed to submit mail. Otherwise, the 973 real UID of the process is looked up in the system password file, 974 and access is granted only if the corresponding login name is on 975 the access list. The username "unknown" is used for processes 976 whose real UID is not found in the password file. To deny mail 977 submission access to all users specify an empty list. </p> 978 979 <p> 980 Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns, 981 separated by commas and/or whitespace. The list is matched left to right, 982 and the search stops on the first match. A "/file/name" pattern is 983 replaced by its contents; 984 a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name matches a lookup key 985 (the lookup result is ignored). Continue long lines by starting the 986 next line with whitespace. Specify "!pattern" to exclude a user 987 name from the list. The form "!/file/name" is supported only in 988 Postfix version 2.4 and later. </p> 989 990 <p> 991 Example: 992 </p> 993 994 <pre> 995 <a href="postconf.5.html#authorized_submit_users">authorized_submit_users</a> = !www, static:all 996 </pre> 997 998 <p> 999 This feature is available in Postfix 2.2 and later. 1000 </p> 1001 1002 1003 </DD> 1004 1005 <DT><b><a name="authorized_verp_clients">authorized_verp_clients</a> 1006 (default: $<a href="postconf.5.html#mynetworks">mynetworks</a>)</b></DT><DD> 1007 1008 <p> What SMTP clients are allowed to specify the XVERP command. 1009 This command requests that mail be delivered one recipient at a 1010 time with a per recipient return address. </p> 1011 1012 <p> By default, only trusted clients are allowed to specify XVERP. 1013 </p> 1014 1015 <p> This parameter was introduced with Postfix version 1.1. Postfix 1016 version 2.1 renamed this parameter to <a href="postconf.5.html#smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a> 1017 and changed the default to none. </p> 1018 1019 <p> Specify a list of network/netmask patterns, separated by commas 1020 and/or whitespace. The mask specifies the number of bits in the 1021 network part of a host address. You can also specify hostnames or 1022 .domain names (the initial dot causes the domain to match any name 1023 below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" 1024 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 1025 is matched when a table entry matches a lookup string (the lookup 1026 result is ignored). Continue long lines by starting the next line 1027 with whitespace. Specify "!pattern" to exclude an address or network 1028 block from the list. The form "!/file/name" is supported only in 1029 Postfix version 2.4 and later. </p> 1030 1031 <p> Note: IP version 6 address information must be specified inside 1032 <tt>[]</tt> in the <a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a> value, and in files 1033 specified with "/file/name". IP version 6 addresses contain the 1034 ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 1035 pattern. </p> 1036 1037 1038 </DD> 1039 1040 <DT><b><a name="backwards_bounce_logfile_compatibility">backwards_bounce_logfile_compatibility</a> 1041 (default: yes)</b></DT><DD> 1042 1043 <p> 1044 Produce additional <a href="bounce.8.html">bounce(8)</a> logfile records that can be read by 1045 Postfix versions before 2.0. The current and more extensible "name = 1046 value" format is needed in order to implement more sophisticated 1047 functionality. 1048 </p> 1049 1050 <p> 1051 This feature is available in Postfix 2.1 and later. 1052 </p> 1053 1054 1055 </DD> 1056 1057 <DT><b><a name="berkeley_db_create_buffer_size">berkeley_db_create_buffer_size</a> 1058 (default: 16777216)</b></DT><DD> 1059 1060 <p> 1061 The per-table I/O buffer size for programs that create Berkeley DB 1062 hash or btree tables. Specify a byte count. 1063 </p> 1064 1065 <p> 1066 This feature is available in Postfix 2.0 and later. 1067 </p> 1068 1069 1070 </DD> 1071 1072 <DT><b><a name="berkeley_db_read_buffer_size">berkeley_db_read_buffer_size</a> 1073 (default: 131072)</b></DT><DD> 1074 1075 <p> 1076 The per-table I/O buffer size for programs that read Berkeley DB 1077 hash or btree tables. Specify a byte count. 1078 </p> 1079 1080 <p> 1081 This feature is available in Postfix 2.0 and later. 1082 </p> 1083 1084 1085 </DD> 1086 1087 <DT><b><a name="best_mx_transport">best_mx_transport</a> 1088 (default: empty)</b></DT><DD> 1089 1090 <p> 1091 Where the Postfix SMTP client should deliver mail when it detects 1092 a "mail loops back to myself" error condition. This happens when 1093 the local MTA is the best SMTP mail exchanger for a destination 1094 not listed in $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>, $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, 1095 $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, or $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. By default, 1096 the Postfix SMTP client returns such mail as undeliverable. 1097 </p> 1098 1099 <p> 1100 Specify, for example, "<a href="postconf.5.html#best_mx_transport">best_mx_transport</a> = local" to pass the mail 1101 from the Postfix SMTP client to the <a href="local.8.html">local(8)</a> delivery agent. You 1102 can specify 1103 any message delivery "transport" or "transport:nexthop" that is 1104 defined in the <a href="master.5.html">master.cf</a> file. See the <a href="transport.5.html">transport(5)</a> manual page 1105 for the syntax and meaning of "transport" or "transport:nexthop". 1106 </p> 1107 1108 <p> 1109 However, this feature is expensive because it ties up a Postfix 1110 SMTP client process while the <a href="local.8.html">local(8)</a> delivery agent is doing its 1111 work. It is more efficient (for Postfix) to list all <a href="VIRTUAL_README.html#canonical">hosted domains</a> 1112 in a table or database. 1113 </p> 1114 1115 1116 </DD> 1117 1118 <DT><b><a name="biff">biff</a> 1119 (default: yes)</b></DT><DD> 1120 1121 <p> 1122 Whether or not to use the local <a href="postconf.5.html#biff">biff</a> service. This service sends 1123 "new mail" notifications to users who have requested new mail 1124 notification with the UNIX command "<a href="postconf.5.html#biff">biff</a> y". 1125 </p> 1126 1127 <p> 1128 For compatibility reasons this feature is on by default. On systems 1129 with lots of interactive users, the <a href="postconf.5.html#biff">biff</a> service can be a performance 1130 drain. Specify "<a href="postconf.5.html#biff">biff</a> = no" in <a href="postconf.5.html">main.cf</a> to disable. 1131 </p> 1132 1133 1134 </DD> 1135 1136 <DT><b><a name="body_checks">body_checks</a> 1137 (default: empty)</b></DT><DD> 1138 1139 <p> Optional lookup tables for content inspection as specified in 1140 the <a href="header_checks.5.html">body_checks(5)</a> manual page. </p> 1141 1142 <p> Note: with Postfix versions before 2.0, these rules inspect 1143 all content after the primary message headers. </p> 1144 1145 1146 </DD> 1147 1148 <DT><b><a name="body_checks_size_limit">body_checks_size_limit</a> 1149 (default: 51200)</b></DT><DD> 1150 1151 <p> 1152 How much text in a message body segment (or attachment, if you 1153 prefer to use that term) is subjected to <a href="postconf.5.html#body_checks">body_checks</a> inspection. 1154 The amount of text is limited to avoid scanning huge attachments. 1155 </p> 1156 1157 <p> 1158 This feature is available in Postfix 2.0 and later. 1159 </p> 1160 1161 1162 </DD> 1163 1164 <DT><b><a name="bounce_notice_recipient">bounce_notice_recipient</a> 1165 (default: postmaster)</b></DT><DD> 1166 1167 <p> 1168 The recipient of postmaster notifications with the message headers 1169 of mail that Postfix did not deliver and of SMTP conversation 1170 transcripts of mail that Postfix did not receive. This feature is 1171 enabled with the <a href="postconf.5.html#notify_classes">notify_classes</a> parameter. </p> 1172 1173 1174 </DD> 1175 1176 <DT><b><a name="bounce_queue_lifetime">bounce_queue_lifetime</a> 1177 (default: 5d)</b></DT><DD> 1178 1179 <p> 1180 The maximal time a bounce message is queued before it is considered 1181 undeliverable. By default, this is the same as the queue life time 1182 for regular mail. 1183 </p> 1184 1185 <p> 1186 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 1187 The default time unit is d (days). 1188 </p> 1189 1190 <p> 1191 Specify 0 when mail delivery should be tried only once. 1192 </p> 1193 1194 <p> 1195 This feature is available in Postfix 2.1 and later. 1196 </p> 1197 1198 1199 </DD> 1200 1201 <DT><b><a name="bounce_service_name">bounce_service_name</a> 1202 (default: bounce)</b></DT><DD> 1203 1204 <p> 1205 The name of the <a href="bounce.8.html">bounce(8)</a> service. This service maintains a record 1206 of failed delivery attempts and generates non-delivery notifications. 1207 </p> 1208 1209 <p> 1210 This feature is available in Postfix 2.0 and later. 1211 </p> 1212 1213 1214 </DD> 1215 1216 <DT><b><a name="bounce_size_limit">bounce_size_limit</a> 1217 (default: 50000)</b></DT><DD> 1218 1219 <p> The maximal amount of original message text that is sent in a 1220 non-delivery notification. Specify a byte count. A message is 1221 returned as either message/rfc822 (the complete original) or as 1222 text/rfc822-headers (the headers only). With Postfix version 2.4 1223 and earlier, a message is always returned as message/rfc822 and is 1224 truncated when it exceeds the size limit. 1225 </p> 1226 1227 <p> Notes: </p> 1228 1229 <ul> 1230 1231 <li> <p> If you increase this limit, then you should increase the 1232 <a href="postconf.5.html#mime_nesting_limit">mime_nesting_limit</a> value proportionally. </p> 1233 1234 <li> <p> Be careful when making changes. Excessively large values 1235 will result in the loss of non-delivery notifications, when a bounce 1236 message size exceeds a local or remote MTA's message size limit. 1237 </p> 1238 1239 </ul> 1240 1241 1242 </DD> 1243 1244 <DT><b><a name="bounce_template_file">bounce_template_file</a> 1245 (default: empty)</b></DT><DD> 1246 1247 <p> Pathname of a configuration file with bounce message templates. 1248 These override the built-in templates of delivery status notification 1249 (DSN) messages for undeliverable mail, for delayed mail, successful 1250 delivery, or delivery verification. The <a href="bounce.5.html">bounce(5)</a> manual page 1251 describes how to edit and test template files. </p> 1252 1253 <p> Template message body text may contain $name references to 1254 Postfix configuration parameters. The result of $name expansion can 1255 be previewed with "<b>postconf -b <i>file_name</i></b>" before the file 1256 is placed into the Postfix configuration directory. </p> 1257 1258 <p> This feature is available in Postfix 2.3 and later. </p> 1259 1260 1261 </DD> 1262 1263 <DT><b><a name="broken_sasl_auth_clients">broken_sasl_auth_clients</a> 1264 (default: no)</b></DT><DD> 1265 1266 <p> 1267 Enable inter-operability with SMTP clients that implement an obsolete 1268 version of the AUTH command (<a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a>). Examples of such clients 1269 are MicroSoft Outlook Express version 4 and MicroSoft Exchange 1270 version 5.0. 1271 </p> 1272 1273 <p> 1274 Specify "<a href="postconf.5.html#broken_sasl_auth_clients">broken_sasl_auth_clients</a> = yes" to have Postfix advertise 1275 AUTH support in a non-standard way. 1276 </p> 1277 1278 1279 </DD> 1280 1281 <DT><b><a name="canonical_classes">canonical_classes</a> 1282 (default: envelope_sender, envelope_recipient, header_sender, header_recipient)</b></DT><DD> 1283 1284 <p> What addresses are subject to <a href="postconf.5.html#canonical_maps">canonical_maps</a> address mapping. 1285 By default, <a href="postconf.5.html#canonical_maps">canonical_maps</a> address mapping is applied to envelope 1286 sender and recipient addresses, and to header sender and header 1287 recipient addresses. </p> 1288 1289 <p> Specify one or more of: envelope_sender, envelope_recipient, 1290 header_sender, header_recipient </p> 1291 1292 <p> This feature is available in Postfix 2.2 and later. </p> 1293 1294 1295 </DD> 1296 1297 <DT><b><a name="canonical_maps">canonical_maps</a> 1298 (default: empty)</b></DT><DD> 1299 1300 <p> 1301 Optional address mapping lookup tables for message headers and 1302 envelopes. The mapping is applied to both sender and recipient 1303 addresses, in both envelopes and in headers, as controlled 1304 with the <a href="postconf.5.html#canonical_classes">canonical_classes</a> parameter. This is typically used 1305 to clean up dirty addresses from legacy mail systems, or to replace 1306 login names by Firstname.Lastname. The table format and lookups 1307 are documented in <a href="canonical.5.html">canonical(5)</a>. For an overview of Postfix address 1308 manipulations see the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> document. 1309 </p> 1310 1311 <p> 1312 If you use this feature, run "<b>postmap /etc/postfix/canonical</b>" to 1313 build the necessary DBM or DB file after every change. The changes 1314 will become visible after a minute or so. Use "<b>postfix reload</b>" 1315 to eliminate the delay. 1316 </p> 1317 1318 <p> Note: with Postfix version 2.2, message header address mapping 1319 happens only when message header address rewriting is enabled: </p> 1320 1321 <ul> 1322 1323 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 1324 1325 <li> The message is received from a network client that matches 1326 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 1327 1328 <li> The message is received from the network, and the 1329 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 1330 1331 </ul> 1332 1333 <p> To get the behavior before Postfix version 2.2, specify 1334 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 1335 1336 <p> 1337 Examples: 1338 </p> 1339 1340 <pre> 1341 <a href="postconf.5.html#canonical_maps">canonical_maps</a> = dbm:/etc/postfix/canonical 1342 <a href="postconf.5.html#canonical_maps">canonical_maps</a> = hash:/etc/postfix/canonical 1343 </pre> 1344 1345 1346 </DD> 1347 1348 <DT><b><a name="cleanup_service_name">cleanup_service_name</a> 1349 (default: cleanup)</b></DT><DD> 1350 1351 <p> 1352 The name of the <a href="cleanup.8.html">cleanup(8)</a> service. This service rewrites addresses 1353 into the standard form, and performs <a href="canonical.5.html">canonical(5)</a> address mapping 1354 and <a href="virtual.5.html">virtual(5)</a> aliasing. 1355 </p> 1356 1357 <p> 1358 This feature is available in Postfix 2.0 and later. 1359 </p> 1360 1361 1362 </DD> 1363 1364 <DT><b><a name="command_directory">command_directory</a> 1365 (default: see "postconf -d" output)</b></DT><DD> 1366 1367 <p> 1368 The location of all postfix administrative commands. 1369 </p> 1370 1371 1372 </DD> 1373 1374 <DT><b><a name="command_execution_directory">command_execution_directory</a> 1375 (default: empty)</b></DT><DD> 1376 1377 <p> The <a href="local.8.html">local(8)</a> delivery agent working directory for delivery to 1378 external command. Failure to change directory causes the delivery 1379 to be deferred. </p> 1380 1381 <p> The following $name expansions are done on <a href="postconf.5.html#command_execution_directory">command_execution_directory</a> 1382 before the directory is changed. Expansion happens in the context 1383 of the delivery request. The result of $name expansion is filtered 1384 with the character set that is specified with the 1385 <a href="postconf.5.html#execution_directory_expansion_filter">execution_directory_expansion_filter</a> parameter. </p> 1386 1387 <dl> 1388 1389 <dt><b>$user</b></dt> 1390 1391 <dd>The recipient's username. </dd> 1392 1393 <dt><b>$shell</b></dt> 1394 1395 <dd>The recipient's login shell pathname. </dd> 1396 1397 <dt><b>$home</b></dt> 1398 1399 <dd>The recipient's home directory. </dd> 1400 1401 <dt><b>$recipient</b></dt> 1402 1403 <dd>The full recipient address. </dd> 1404 1405 <dt><b>$extension</b></dt> 1406 1407 <dd>The optional recipient address extension. </dd> 1408 1409 <dt><b>$domain</b></dt> 1410 1411 <dd>The recipient domain. </dd> 1412 1413 <dt><b>$local</b></dt> 1414 1415 <dd>The entire recipient localpart. </dd> 1416 1417 <dt><b>$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b></dt> 1418 1419 <dd>The system-wide recipient address extension delimiter. </dd> 1420 1421 <dt><b>${name?value}</b></dt> 1422 1423 <dd>Expands to <i>value</i> when <i>$name</i> is non-empty. </dd> 1424 1425 <dt><b>${name:value}</b></dt> 1426 1427 <dd>Expands to <i>value</i> when <i>$name</i> is empty. </dd> 1428 1429 </dl> 1430 1431 <p> 1432 Instead of $name you can also specify ${name} or $(name). 1433 </p> 1434 1435 <p> This feature is available in Postfix 2.2 and later. </p> 1436 1437 1438 </DD> 1439 1440 <DT><b><a name="command_expansion_filter">command_expansion_filter</a> 1441 (default: see "postconf -d" output)</b></DT><DD> 1442 1443 <p> 1444 Restrict the characters that the <a href="local.8.html">local(8)</a> delivery agent allows in 1445 $name expansions of $<a href="postconf.5.html#mailbox_command">mailbox_command</a> and $<a href="postconf.5.html#command_execution_directory">command_execution_directory</a>. 1446 Characters outside the 1447 allowed set are replaced by underscores. 1448 </p> 1449 1450 1451 </DD> 1452 1453 <DT><b><a name="command_time_limit">command_time_limit</a> 1454 (default: 1000s)</b></DT><DD> 1455 1456 <p> 1457 Time limit for delivery to external commands. This limit is used 1458 by the <a href="local.8.html">local(8)</a> delivery agent, and is the default time limit for 1459 delivery by the <a href="pipe.8.html">pipe(8)</a> delivery agent. 1460 </p> 1461 1462 <p> 1463 Note: if you set this time limit to a large value you must update the 1464 global <a href="postconf.5.html#ipc_timeout">ipc_timeout</a> parameter as well. 1465 </p> 1466 1467 1468 </DD> 1469 1470 <DT><b><a name="config_directory">config_directory</a> 1471 (default: see "postconf -d" output)</b></DT><DD> 1472 1473 <p> The default location of the Postfix <a href="postconf.5.html">main.cf</a> and <a href="master.5.html">master.cf</a> 1474 configuration files. This can be overruled via the following 1475 mechanisms: </p> 1476 1477 <ul> 1478 1479 <li> <p> The MAIL_CONFIG environment variable (daemon processes 1480 and commands). </p> 1481 1482 <li> <p> The "-c" command-line option (commands only). </p> 1483 1484 </ul> 1485 1486 <p> With Postfix command that run with set-gid privileges, a 1487 <a href="postconf.5.html#config_directory">config_directory</a> override requires either root privileges, or it 1488 requires that the directory is listed with the <a href="postconf.5.html#alternate_config_directories">alternate_config_directories</a> 1489 parameter in the default <a href="postconf.5.html">main.cf</a> file. </p> 1490 1491 1492 </DD> 1493 1494 <DT><b><a name="connection_cache_protocol_timeout">connection_cache_protocol_timeout</a> 1495 (default: 5s)</b></DT><DD> 1496 1497 <p> Time limit for connection cache connect, send or receive 1498 operations. The time limit is enforced in the client. </p> 1499 1500 <p> This feature is available in Postfix 2.3 and later. </p> 1501 1502 1503 </DD> 1504 1505 <DT><b><a name="connection_cache_service_name">connection_cache_service_name</a> 1506 (default: scache)</b></DT><DD> 1507 1508 <p> The name of the <a href="scache.8.html">scache(8)</a> connection cache service. This service 1509 maintains a limited pool of cached sessions. </p> 1510 1511 <p> This feature is available in Postfix 2.2 and later. </p> 1512 1513 1514 </DD> 1515 1516 <DT><b><a name="connection_cache_status_update_time">connection_cache_status_update_time</a> 1517 (default: 600s)</b></DT><DD> 1518 1519 <p> How frequently the <a href="scache.8.html">scache(8)</a> server logs usage statistics with 1520 connection cache hit and miss rates for logical destinations and for 1521 physical endpoints. </p> 1522 1523 1524 </DD> 1525 1526 <DT><b><a name="connection_cache_ttl_limit">connection_cache_ttl_limit</a> 1527 (default: 2s)</b></DT><DD> 1528 1529 <p> The maximal time-to-live value that the <a href="scache.8.html">scache(8)</a> connection 1530 cache server 1531 allows. Requests that specify a larger TTL will be stored with the 1532 maximum allowed TTL. The purpose of this additional control is to 1533 protect the infrastructure against careless people. The cache TTL 1534 is already bounded by $<a href="postconf.5.html#max_idle">max_idle</a>. </p> 1535 1536 1537 </DD> 1538 1539 <DT><b><a name="content_filter">content_filter</a> 1540 (default: empty)</b></DT><DD> 1541 1542 <p> After the message is queued, send the entire message to the 1543 specified <i>transport:destination</i>. The <i>transport</i> name 1544 specifies the first field of a mail delivery agent definition in 1545 <a href="master.5.html">master.cf</a>; the syntax of the next-hop <i>destination</i> is described 1546 in the manual page of the corresponding delivery agent. More 1547 information about external content filters is in the Postfix 1548 <a href="FILTER_README.html">FILTER_README</a> file. </p> 1549 1550 <p> Notes: </p> 1551 1552 <ul> 1553 1554 <li> <p> This setting has lower precedence than a FILTER action 1555 that is specified in an <a href="access.5.html">access(5)</a>, <a href="header_checks.5.html">header_checks(5)</a> or <a href="header_checks.5.html">body_checks(5)</a> 1556 table. </p> 1557 1558 <li> <p> The meaning of an empty next-hop filter <i>destination</i> 1559 is version dependent. Postfix 2.7 and later will use the recipient 1560 domain; earlier versions will use $<a href="postconf.5.html#myhostname">myhostname</a>. Specify 1561 "<a href="postconf.5.html#default_filter_nexthop">default_filter_nexthop</a> = $<a href="postconf.5.html#myhostname">myhostname</a>" for compatibility with Postfix 1562 2.6 or earlier, or specify a <a href="postconf.5.html#content_filter">content_filter</a> value with an explicit 1563 next-hop <i>destination</i>. </p> 1564 1565 </ul> 1566 1567 1568 </DD> 1569 1570 <DT><b><a name="cyrus_sasl_config_path">cyrus_sasl_config_path</a> 1571 (default: empty)</b></DT><DD> 1572 1573 <p> Search path for Cyrus SASL application configuration files, 1574 currently used only to locate the $<a href="postconf.5.html#smtpd_sasl_path">smtpd_sasl_path</a>.conf file. 1575 Specify zero or more directories separated by a colon character, 1576 or an empty value to use Cyrus SASL's built-in search path. </p> 1577 1578 <p> This feature is available in Postfix 2.5 and later when compiled 1579 with Cyrus SASL 2.1.22 or later. </p> 1580 1581 1582 </DD> 1583 1584 <DT><b><a name="daemon_directory">daemon_directory</a> 1585 (default: see "postconf -d" output)</b></DT><DD> 1586 1587 <p> 1588 The directory with Postfix support programs and daemon programs. 1589 These should not be invoked directly by humans. The directory must 1590 be owned by root. 1591 </p> 1592 1593 1594 </DD> 1595 1596 <DT><b><a name="daemon_timeout">daemon_timeout</a> 1597 (default: 18000s)</b></DT><DD> 1598 1599 <p> How much time a Postfix daemon process may take to handle a 1600 request before it is terminated by a built-in watchdog timer. </p> 1601 1602 <p> 1603 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 1604 The default time unit is s (seconds). 1605 </p> 1606 1607 1608 </DD> 1609 1610 <DT><b><a name="data_directory">data_directory</a> 1611 (default: see "postconf -d" output)</b></DT><DD> 1612 1613 <p> The directory with Postfix-writable data files (for example: 1614 caches, pseudo-random numbers). This directory must be owned by 1615 the <a href="postconf.5.html#mail_owner">mail_owner</a> account, and must not be shared with non-Postfix 1616 software. </p> 1617 1618 <p> This feature is available in Postfix 2.5 and later. </p> 1619 1620 1621 </DD> 1622 1623 <DT><b><a name="debug_peer_level">debug_peer_level</a> 1624 (default: 2)</b></DT><DD> 1625 1626 <p> The increment in verbose logging level when a remote client or 1627 server matches a pattern in the <a href="postconf.5.html#debug_peer_list">debug_peer_list</a> parameter. </p> 1628 1629 1630 </DD> 1631 1632 <DT><b><a name="debug_peer_list">debug_peer_list</a> 1633 (default: empty)</b></DT><DD> 1634 1635 <p> Optional list of remote client or server hostname or network 1636 address patterns that cause the verbose logging level to increase 1637 by the amount specified in $<a href="postconf.5.html#debug_peer_level">debug_peer_level</a>. </p> 1638 1639 <p> Specify domain names, network/netmask patterns, "/file/name" 1640 patterns or "<a href="DATABASE_README.html">type:table</a>" lookup tables. The right-hand side result 1641 from "<a href="DATABASE_README.html">type:table</a>" lookups is ignored. </p> 1642 1643 <p> Pattern matching of domain names is controlled by the 1644 <a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> parameter. </p> 1645 1646 <p> 1647 Examples: 1648 </p> 1649 1650 <pre> 1651 <a href="postconf.5.html#debug_peer_list">debug_peer_list</a> = 127.0.0.1 1652 <a href="postconf.5.html#debug_peer_list">debug_peer_list</a> = example.com 1653 </pre> 1654 1655 1656 </DD> 1657 1658 <DT><b><a name="debugger_command">debugger_command</a> 1659 (default: empty)</b></DT><DD> 1660 1661 <p> 1662 The external command to execute when a Postfix daemon program is 1663 invoked with the -D option. 1664 </p> 1665 1666 <p> 1667 Use "command .. & sleep 5" so that the debugger can attach before 1668 the process marches on. If you use an X-based debugger, be sure to 1669 set up your XAUTHORITY environment variable before starting Postfix. 1670 </p> 1671 1672 <p> 1673 Example: 1674 </p> 1675 1676 <pre> 1677 <a href="postconf.5.html#debugger_command">debugger_command</a> = 1678 PATH=/usr/bin:/usr/X11R6/bin 1679 ddd $<a href="postconf.5.html#daemon_directory">daemon_directory</a>/$<a href="postconf.5.html#process_name">process_name</a> $<a href="postconf.5.html#process_id">process_id</a> & sleep 5 1680 </pre> 1681 1682 1683 </DD> 1684 1685 <DT><b><a name="default_database_type">default_database_type</a> 1686 (default: see "postconf -d" output)</b></DT><DD> 1687 1688 <p> 1689 The default database type for use in <a href="newaliases.1.html">newaliases(1)</a>, <a href="postalias.1.html">postalias(1)</a> 1690 and <a href="postmap.1.html">postmap(1)</a> commands. On many UNIX systems the default type is 1691 either <b>dbm</b> or <b>hash</b>. The default setting is frozen 1692 when the Postfix system is built. 1693 </p> 1694 1695 <p> 1696 Examples: 1697 </p> 1698 1699 <pre> 1700 <a href="postconf.5.html#default_database_type">default_database_type</a> = hash 1701 <a href="postconf.5.html#default_database_type">default_database_type</a> = dbm 1702 </pre> 1703 1704 1705 </DD> 1706 1707 <DT><b><a name="default_delivery_slot_cost">default_delivery_slot_cost</a> 1708 (default: 5)</b></DT><DD> 1709 1710 <p> 1711 How often the Postfix queue manager's scheduler is allowed to 1712 preempt delivery of one message with another. 1713 </p> 1714 1715 <p> 1716 Each transport maintains a so-called "available delivery slot counter" 1717 for each message. One message can be preempted by another one when 1718 the other message can be delivered using no more delivery slots 1719 (i.e., invocations of delivery agents) than the current message 1720 counter has accumulated (or will eventually accumulate - see about 1721 slot loans below). This parameter controls how often is the counter 1722 incremented - it happens after each <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> 1723 recipients have been delivered. 1724 </p> 1725 1726 <p> 1727 The cost of 0 is used to disable the preempting scheduling completely. 1728 The minimum value the scheduling algorithm can use is 2 - use it 1729 if you want to maximize the message throughput rate. Although there 1730 is no maximum, it doesn't make much sense to use values above say 1731 50. 1732 </p> 1733 1734 <p> 1735 The only reason why the value of 2 is not the default is the way 1736 this parameter affects the delivery of mailing-list mail. In the 1737 worst case, their delivery can take somewhere between (cost+1/cost) 1738 and (cost/cost-1) times more than if the preemptive scheduler was 1739 disabled. The default value of 5 turns out to provide reasonable 1740 message response times while making sure the mailing-list deliveries 1741 are not extended by more than 20-25 percent even in the worst case. 1742 </p> 1743 1744 <p> Use <a href="postconf.5.html#transport_delivery_slot_cost"><i>transport</i>_delivery_slot_cost</a> to specify a 1745 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1746 name of the message delivery transport. 1747 </p> 1748 1749 <p> 1750 Examples: 1751 </p> 1752 1753 <pre> 1754 <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> = 0 1755 <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> = 2 1756 </pre> 1757 1758 1759 </DD> 1760 1761 <DT><b><a name="default_delivery_slot_discount">default_delivery_slot_discount</a> 1762 (default: 50)</b></DT><DD> 1763 1764 <p> 1765 The default value for transport-specific _delivery_slot_discount 1766 settings. 1767 </p> 1768 1769 <p> 1770 This parameter speeds up the moment when a message preemption can 1771 happen. Instead of waiting until the full amount of delivery slots 1772 required is available, the preemption can happen when 1773 transport_delivery_slot_discount percent of the required amount 1774 plus transport_delivery_slot_loan still remains to be accumulated. 1775 Note that the full amount will still have to be accumulated before 1776 another preemption can take place later. 1777 </p> 1778 1779 <p> Use <a href="postconf.5.html#transport_delivery_slot_discount"><i>transport</i>_delivery_slot_discount</a> to specify a 1780 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1781 name of the message delivery transport. 1782 </p> 1783 1784 1785 </DD> 1786 1787 <DT><b><a name="default_delivery_slot_loan">default_delivery_slot_loan</a> 1788 (default: 3)</b></DT><DD> 1789 1790 <p> 1791 The default value for transport-specific _delivery_slot_loan 1792 settings. 1793 </p> 1794 1795 <p> 1796 This parameter speeds up the moment when a message preemption can 1797 happen. Instead of waiting until the full amount of delivery slots 1798 required is available, the preemption can happen when 1799 transport_delivery_slot_discount percent of the required amount 1800 plus transport_delivery_slot_loan still remains to be accumulated. 1801 Note that the full amount will still have to be accumulated before 1802 another preemption can take place later. 1803 </p> 1804 1805 <p> Use <a href="postconf.5.html#transport_delivery_slot_loan"><i>transport</i>_delivery_slot_loan</a> to specify a 1806 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1807 name of the message delivery transport. 1808 </p> 1809 1810 1811 </DD> 1812 1813 <DT><b><a name="default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a> 1814 (default: 1)</b></DT><DD> 1815 1816 <p> How many pseudo-cohorts must suffer connection or handshake 1817 failure before a specific destination is considered unavailable 1818 (and further delivery is suspended). Specify zero to disable this 1819 feature. A destination's pseudo-cohort failure count is reset each 1820 time a delivery completes without connection or handshake failure 1821 for that specific destination. </p> 1822 1823 <p> A pseudo-cohort is the number of deliveries equal to a destination's 1824 delivery concurrency. </p> 1825 1826 <p> Use <a href="postconf.5.html#transport_destination_concurrency_failed_cohort_limit"><i>transport</i>_destination_concurrency_failed_cohort_limit</a> to specify 1827 a transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1828 name of the message delivery transport. </p> 1829 1830 <p> This feature is available in Postfix 2.5. The default setting 1831 is compatible with earlier Postfix versions. </p> 1832 1833 1834 </DD> 1835 1836 <DT><b><a name="default_destination_concurrency_limit">default_destination_concurrency_limit</a> 1837 (default: 20)</b></DT><DD> 1838 1839 <p> 1840 The default maximal number of parallel deliveries to the same 1841 destination. This is the default limit for delivery via the <a href="lmtp.8.html">lmtp(8)</a>, 1842 <a href="pipe.8.html">pipe(8)</a>, <a href="smtp.8.html">smtp(8)</a> and <a href="virtual.8.html">virtual(8)</a> delivery agents. 1843 With per-destination recipient limit > 1, a destination is a domain, 1844 otherwise it is a recipient. 1845 </p> 1846 1847 <p> Use <a href="postconf.5.html#transport_destination_concurrency_limit"><i>transport</i>_destination_concurrency_limit</a> to specify a 1848 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1849 name of the message delivery transport. 1850 </p> 1851 1852 1853 </DD> 1854 1855 <DT><b><a name="default_destination_concurrency_negative_feedback">default_destination_concurrency_negative_feedback</a> 1856 (default: 1)</b></DT><DD> 1857 1858 <p> The per-destination amount of delivery concurrency negative 1859 feedback, after a delivery completes with a connection or handshake 1860 failure. Feedback values are in the range 0..1 inclusive. With 1861 negative feedback, concurrency is decremented at the beginning of 1862 a sequence of length 1/feedback. This is unlike positive feedback, 1863 where concurrency is incremented at the end of a sequence of length 1864 1/feedback. </p> 1865 1866 <p> As of Postfix version 2.5, negative feedback cannot reduce 1867 delivery concurrency to zero. Instead, a destination is marked 1868 dead (further delivery suspended) after the failed pseudo-cohort 1869 count reaches $<a href="postconf.5.html#default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a> 1870 (or $<a href="postconf.5.html#transport_destination_concurrency_failed_cohort_limit"><i>transport</i>_destination_concurrency_failed_cohort_limit</a>). 1871 To make the scheduler completely immune to connection or handshake 1872 failures, specify a zero feedback value and a zero failed pseudo-cohort 1873 limit. </p> 1874 1875 <p> Specify one of the following forms: </p> 1876 1877 <dl> 1878 1879 <dt> <b><i>number</i> </b> </dt> 1880 1881 <dt> <b><i>number</i> / <i>number</i> </b> </dt> 1882 1883 <dd> Constant feedback. The value must be in the range 0..1 inclusive. 1884 The default setting of "1" is compatible with Postfix versions 1885 before 2.5, where a destination's delivery concurrency is throttled 1886 down to zero (and further delivery suspended) after a single failed 1887 pseudo-cohort. </dd> 1888 1889 <dt> <b><i>number</i> / concurrency </b> </dt> 1890 1891 <dd> Variable feedback of "<i>number</i> / (delivery concurrency)". 1892 The <i>number</i> must be in the range 0..1 inclusive. With 1893 <i>number</i> equal to "1", a destination's delivery concurrency 1894 is decremented by 1 after each failed pseudo-cohort. </dd> 1895 1896 </dl> 1897 1898 <p> A pseudo-cohort is the number of deliveries equal to a destination's 1899 delivery concurrency. </p> 1900 1901 <p> Use <a href="postconf.5.html#transport_destination_concurrency_negative_feedback"><i>transport</i>_destination_concurrency_negative_feedback</a> 1902 to specify a transport-specific override, where <i>transport</i> 1903 is the <a href="master.5.html">master.cf</a> 1904 name of the message delivery transport. </p> 1905 1906 <p> This feature is available in Postfix 2.5. The default setting 1907 is compatible with earlier Postfix versions. </p> 1908 1909 1910 </DD> 1911 1912 <DT><b><a name="default_destination_concurrency_positive_feedback">default_destination_concurrency_positive_feedback</a> 1913 (default: 1)</b></DT><DD> 1914 1915 <p> The per-destination amount of delivery concurrency positive 1916 feedback, after a delivery completes without connection or handshake 1917 failure. Feedback values are in the range 0..1 inclusive. The 1918 concurrency increases until it reaches the per-destination maximal 1919 concurrency limit. With positive feedback, concurrency is incremented 1920 at the end of a sequence with length 1/feedback. This is unlike 1921 negative feedback, where concurrency is decremented at the start 1922 of a sequence of length 1/feedback. </p> 1923 1924 <p> Specify one of the following forms: </p> 1925 1926 <dl> 1927 1928 <dt> <b><i>number</i> </b> </dt> 1929 1930 <dt> <b><i>number</i> / <i>number</i> </b> </dt> 1931 1932 <dd> Constant feedback. The value must be in the range 0..1 1933 inclusive. The default setting of "1" is compatible with Postfix 1934 versions before 2.5, where a destination's delivery concurrency 1935 doubles after each successful pseudo-cohort. </dd> 1936 1937 <dt> <b><i>number</i> / concurrency </b> </dt> 1938 1939 <dd> Variable feedback of "<i>number</i> / (delivery concurrency)". 1940 The <i>number</i> must be in the range 0..1 inclusive. With 1941 <i>number</i> equal to "1", a destination's delivery concurrency 1942 is incremented by 1 after each successful pseudo-cohort. </dd> 1943 1944 </dl> 1945 1946 <p> A pseudo-cohort is the number of deliveries equal to a destination's 1947 delivery concurrency. </p> 1948 1949 <p> Use <a href="postconf.5.html#transport_destination_concurrency_positive_feedback"><i>transport</i>_destination_concurrency_positive_feedback</a> 1950 to specify a transport-specific override, where <i>transport</i> 1951 is the <a href="master.5.html">master.cf</a> name of the message delivery transport. </p> 1952 1953 <p> This feature is available in Postfix 2.5 and later. </p> 1954 1955 1956 </DD> 1957 1958 <DT><b><a name="default_destination_rate_delay">default_destination_rate_delay</a> 1959 (default: 0s)</b></DT><DD> 1960 1961 <p> The default amount of delay that is inserted between individual 1962 deliveries to the same destination; with per-destination recipient 1963 limit > 1, a destination is a domain, otherwise it is a recipient. 1964 </p> 1965 1966 <p> To enable the delay, specify a non-zero time value (an integral 1967 value plus an optional one-letter suffix that specifies the time 1968 unit). </p> 1969 1970 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 1971 (weeks). The default time unit is s (seconds). </p> 1972 1973 <p> NOTE: the delay is enforced by the queue manager. The delay 1974 timer state does not survive "<b>postfix reload</b>" or "<b>postfix 1975 stop</b>". 1976 </p> 1977 1978 <p> Use <a href="postconf.5.html#transport_destination_rate_delay"><i>transport</i>_destination_rate_delay</a> to specify a 1979 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1980 name of the message delivery transport. 1981 </p> 1982 1983 <p> NOTE: with a non-zero _destination_rate_delay, specify a 1984 <a href="postconf.5.html#transport_destination_concurrency_failed_cohort_limit"><i>transport</i>_destination_concurrency_failed_cohort_limit</a> of 10 1985 or more to prevent Postfix from deferring all mail for the same 1986 destination after only one connection or handshake error. </p> 1987 1988 <p> This feature is available in Postfix 2.5 and later. </p> 1989 1990 1991 </DD> 1992 1993 <DT><b><a name="default_destination_recipient_limit">default_destination_recipient_limit</a> 1994 (default: 50)</b></DT><DD> 1995 1996 <p> 1997 The default maximal number of recipients per message delivery. 1998 This is the default limit for delivery via the <a href="lmtp.8.html">lmtp(8)</a>, <a href="pipe.8.html">pipe(8)</a>, 1999 <a href="smtp.8.html">smtp(8)</a> and <a href="virtual.8.html">virtual(8)</a> delivery agents. 2000 </p> 2001 2002 <p> Setting this parameter to a value of 1 changes the meaning of 2003 the corresponding per-destination concurrency limit from concurrency 2004 per domain into concurrency per recipient. </p> 2005 2006 <p> Use <a href="postconf.5.html#transport_destination_recipient_limit"><i>transport</i>_destination_recipient_limit</a> to specify a 2007 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 2008 name of the message delivery transport. 2009 </p> 2010 2011 2012 </DD> 2013 2014 <DT><b><a name="default_extra_recipient_limit">default_extra_recipient_limit</a> 2015 (default: 1000)</b></DT><DD> 2016 2017 <p> 2018 The default value for the extra per-transport limit imposed on the 2019 number of in-memory recipients. This extra recipient space is 2020 reserved for the cases when the Postfix queue manager's scheduler 2021 preempts one message with another and suddenly needs some extra 2022 recipients slots for the chosen message in order to avoid performance 2023 degradation. 2024 </p> 2025 2026 <p> Use <a href="postconf.5.html#transport_extra_recipient_limit"><i>transport</i>_extra_recipient_limit</a> to specify a 2027 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 2028 name of the message delivery transport. 2029 </p> 2030 2031 2032 </DD> 2033 2034 <DT><b><a name="default_filter_nexthop">default_filter_nexthop</a> 2035 (default: empty)</b></DT><DD> 2036 2037 <p> When a <a href="postconf.5.html#content_filter">content_filter</a> or FILTER request specifies no explicit 2038 next-hop destination, use $<a href="postconf.5.html#default_filter_nexthop">default_filter_nexthop</a> instead; when 2039 that value is empty, use the domain in the recipient address. 2040 Specify "<a href="postconf.5.html#default_filter_nexthop">default_filter_nexthop</a> = $<a href="postconf.5.html#myhostname">myhostname</a>" for compatibility 2041 with Postfix version 2.6 and earlier, or specify an explicit next-hop 2042 destination with each <a href="postconf.5.html#content_filter">content_filter</a> value or FILTER action. </p> 2043 2044 <p> This feature is available in Postfix 2.7 and later. </p> 2045 2046 2047 </DD> 2048 2049 <DT><b><a name="default_minimum_delivery_slots">default_minimum_delivery_slots</a> 2050 (default: 3)</b></DT><DD> 2051 2052 <p> 2053 How many recipients a message must have in order to invoke the 2054 Postfix queue manager's scheduling algorithm at all. Messages 2055 which would never accumulate at least this many delivery slots 2056 (subject to slot cost parameter as well) are never preempted. 2057 </p> 2058 2059 <p> Use <a href="postconf.5.html#transport_minimum_delivery_slots"><i>transport</i>_minimum_delivery_slots</a> to specify a 2060 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 2061 name of the message delivery transport. 2062 </p> 2063 2064 2065 </DD> 2066 2067 <DT><b><a name="default_privs">default_privs</a> 2068 (default: nobody)</b></DT><DD> 2069 2070 <p> 2071 The default rights used by the <a href="local.8.html">local(8)</a> delivery agent for delivery 2072 to external file or command. These rights are used when delivery 2073 is requested from an <a href="aliases.5.html">aliases(5)</a> file that is owned by <b>root</b>, or 2074 when delivery is done on behalf of <b>root</b>. <b>DO NOT SPECIFY A 2075 PRIVILEGED USER OR THE POSTFIX OWNER</b>. 2076 </p> 2077 2078 2079 </DD> 2080 2081 <DT><b><a name="default_process_limit">default_process_limit</a> 2082 (default: 100)</b></DT><DD> 2083 2084 <p> 2085 The default maximal number of Postfix child processes that provide 2086 a given service. This limit can be overruled for specific services 2087 in the <a href="master.5.html">master.cf</a> file. 2088 </p> 2089 2090 2091 </DD> 2092 2093 <DT><b><a name="default_rbl_reply">default_rbl_reply</a> 2094 (default: see "postconf -d" output)</b></DT><DD> 2095 2096 <p> 2097 The default SMTP server response template for a request that is 2098 rejected by an RBL-based restriction. This template can be overruled 2099 by specific entries in the optional <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> lookup table. 2100 </p> 2101 2102 <p> 2103 This feature is available in Postfix 2.0 and later. 2104 </p> 2105 2106 <p> 2107 The template is subject to exactly one level of $name substitution: 2108 </p> 2109 2110 <dl> 2111 2112 <dt><b>$client</b></dt> 2113 2114 <dd>The client hostname and IP address, formatted as name[address]. </dd> 2115 2116 <dt><b>$client_address</b></dt> 2117 2118 <dd>The client IP address. </dd> 2119 2120 <dt><b>$client_name</b></dt> 2121 2122 <dd>The client hostname or "unknown". See <a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> 2123 for more details. </dd> 2124 2125 <dt><b>$reverse_client_name</b></dt> 2126 2127 <dd>The client hostname from address->name lookup, or "unknown". 2128 See <a href="postconf.5.html#reject_unknown_reverse_client_hostname">reject_unknown_reverse_client_hostname</a> for more details. </dd> 2129 2130 <dt><b>$helo_name</b></dt> 2131 2132 <dd>The hostname given in HELO or EHLO command or empty string. </dd> 2133 2134 <dt><b>$rbl_class</b></dt> 2135 2136 <dd>The blacklisted entity type: Client host, Helo command, Sender 2137 address, or Recipient address. </dd> 2138 2139 <dt><b>$rbl_code</b></dt> 2140 2141 <dd>The numerical SMTP response code, as specified with the 2142 <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> configuration parameter. Note: The numerical 2143 SMTP response code is required, and must appear at the start of the 2144 reply. With Postfix version 2.3 and later this information may be followed 2145 by an <a href="http://tools.ietf.org/html/rfc3463">RFC 3463</a> enhanced status code. </dd> 2146 2147 <dt><b>$rbl_domain</b></dt> 2148 2149 <dd>The RBL domain where $rbl_what is blacklisted. </dd> 2150 2151 <dt><b>$rbl_reason</b></dt> 2152 2153 <dd>The reason why $rbl_what is blacklisted, or an empty string. </dd> 2154 2155 <dt><b>$rbl_what</b></dt> 2156 2157 <dd>The entity that is blacklisted (an IP address, a hostname, a domain 2158 name, or an email address whose domain was blacklisted). </dd> 2159 2160 <dt><b>$recipient</b></dt> 2161 2162 <dd>The recipient address or <> in case of the null address. </dd> 2163 2164 <dt><b>$recipient_domain</b></dt> 2165 2166 <dd>The recipient domain or empty string. </dd> 2167 2168 <dt><b>$recipient_name</b></dt> 2169 2170 <dd>The recipient address localpart or <> in case of null address. </dd> 2171 2172 <dt><b>$sender</b></dt> 2173 2174 <dd>The sender address or <> in case of the null address. </dd> 2175 2176 <dt><b>$sender_domain</b></dt> 2177 2178 <dd>The sender domain or empty string. </dd> 2179 2180 <dt><b>$sender_name</b></dt> 2181 2182 <dd>The sender address localpart or <> in case of the null address. </dd> 2183 2184 <dt><b>${name?text}</b></dt> 2185 2186 <dd>Expands to `text' if $name is not empty. </dd> 2187 2188 <dt><b>${name:text}</b></dt> 2189 2190 <dd>Expands to `text' if $name is empty. </dd> 2191 2192 </dl> 2193 2194 <p> 2195 Instead of $name you can also specify ${name} or $(name). 2196 </p> 2197 2198 <p> Note: when an enhanced status code is specified in an RBL reply 2199 template, it is subject to modification. The following transformations 2200 are needed when the same RBL reply template is used for client, 2201 helo, sender, or recipient access restrictions. </p> 2202 2203 <ul> 2204 2205 <li> <p> When rejecting a sender address, the Postfix SMTP server 2206 will transform a recipient DSN status (e.g., 4.1.1-4.1.6) into the 2207 corresponding sender DSN status, and vice versa. </p> 2208 2209 <li> <p> When rejecting non-address information (such as the HELO 2210 command argument or the client hostname/address), the Postfix SMTP 2211 server will transform a sender or recipient DSN status into a generic 2212 non-address DSN status (e.g., 4.0.0). </p> 2213 2214 </ul> 2215 2216 2217 </DD> 2218 2219 <DT><b><a name="default_recipient_limit">default_recipient_limit</a> 2220 (default: 20000)</b></DT><DD> 2221 2222 <p> 2223 The default per-transport upper limit on the number of in-memory 2224 recipients. These limits take priority over the global 2225 <a href="postconf.5.html#qmgr_message_recipient_limit">qmgr_message_recipient_limit</a> after the message has been assigned 2226 to the respective transports. See also <a href="postconf.5.html#default_extra_recipient_limit">default_extra_recipient_limit</a> 2227 and <a href="postconf.5.html#qmgr_message_recipient_minimum">qmgr_message_recipient_minimum</a>. 2228 </p> 2229 2230 <p> Use <a href="postconf.5.html#transport_recipient_limit"><i>transport</i>_recipient_limit</a> to specify a 2231 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 2232 name of the message delivery transport. 2233 </p> 2234 2235 2236 </DD> 2237 2238 <DT><b><a name="default_recipient_refill_delay">default_recipient_refill_delay</a> 2239 (default: 5s)</b></DT><DD> 2240 2241 <p> 2242 The default per-transport maximum delay between recipients refills. 2243 When not all message recipients fit into the memory at once, keep loading 2244 more of them at least once every this many seconds. This is used to 2245 make sure the recipients are refilled in timely manner even when 2246 $<a href="postconf.5.html#default_recipient_refill_limit">default_recipient_refill_limit</a> is too high for too slow deliveries. 2247 </p> 2248 2249 <p> Use <a href="postconf.5.html#transport_recipient_refill_delay"><i>transport</i>_recipient_refill_delay</a> to specify a 2250 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 2251 name of the message delivery transport. 2252 </p> 2253 2254 <p> This feature is available in Postfix 2.4 and later. </p> 2255 2256 2257 </DD> 2258 2259 <DT><b><a name="default_recipient_refill_limit">default_recipient_refill_limit</a> 2260 (default: 100)</b></DT><DD> 2261 2262 <p> 2263 The default per-transport limit on the number of recipients refilled at 2264 once. When not all message recipients fit into the memory at once, keep 2265 loading more of them in batches of at least this many at a time. See also 2266 $<a href="postconf.5.html#default_recipient_refill_delay">default_recipient_refill_delay</a>, which may result in recipient batches 2267 lower than this when this limit is too high for too slow deliveries. 2268 </p> 2269 2270 <p> Use <a href="postconf.5.html#transport_recipient_refill_limit"><i>transport</i>_recipient_refill_limit</a> to specify a 2271 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 2272 name of the message delivery transport. 2273 </p> 2274 2275 <p> This feature is available in Postfix 2.4 and later. </p> 2276 2277 2278 </DD> 2279 2280 <DT><b><a name="default_transport">default_transport</a> 2281 (default: smtp)</b></DT><DD> 2282 2283 <p> 2284 The default mail delivery transport and next-hop destination for 2285 destinations that do not match $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>, 2286 $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>, 2287 or $<a href="postconf.5.html#relay_domains">relay_domains</a>. This information can be overruled with the 2288 <a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a> parameter and with the 2289 <a href="transport.5.html">transport(5)</a> table. </p> 2290 2291 <p> 2292 In order of decreasing precedence, the nexthop destination is taken 2293 from $<a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a>, $<a href="postconf.5.html#default_transport">default_transport</a>, 2294 $<a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>, $<a href="postconf.5.html#relayhost">relayhost</a>, or from the recipient 2295 domain. 2296 </p> 2297 2298 <p> 2299 Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i> 2300 is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>. 2301 The <i>:nexthop</i> destination is optional; its syntax is documented 2302 in the manual page of the corresponding delivery agent. 2303 </p> 2304 2305 <p> 2306 Example: 2307 </p> 2308 2309 <pre> 2310 <a href="postconf.5.html#default_transport">default_transport</a> = uucp:relayhostname 2311 </pre> 2312 2313 2314 </DD> 2315 2316 <DT><b><a name="default_verp_delimiters">default_verp_delimiters</a> 2317 (default: +=)</b></DT><DD> 2318 2319 <p> The two default VERP delimiter characters. These are used when 2320 no explicit delimiters are specified with the SMTP XVERP command 2321 or with the "<b>sendmail -V</b>" command-line option. Specify 2322 characters that are allowed by the <a href="postconf.5.html#verp_delimiter_filter">verp_delimiter_filter</a> setting. 2323 </p> 2324 2325 <p> 2326 This feature is available in Postfix 1.1 and later. 2327 </p> 2328 2329 2330 </DD> 2331 2332 <DT><b><a name="defer_code">defer_code</a> 2333 (default: 450)</b></DT><DD> 2334 2335 <p> 2336 The numerical Postfix SMTP server response code when a remote SMTP 2337 client request is rejected by the "defer" restriction. 2338 </p> 2339 2340 <p> 2341 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 2342 </p> 2343 2344 2345 </DD> 2346 2347 <DT><b><a name="defer_service_name">defer_service_name</a> 2348 (default: defer)</b></DT><DD> 2349 2350 <p> 2351 The name of the defer service. This service is implemented by the 2352 <a href="bounce.8.html">bounce(8)</a> daemon and maintains a record 2353 of failed delivery attempts and generates non-delivery notifications. 2354 </p> 2355 2356 <p> 2357 This feature is available in Postfix 2.0 and later. 2358 </p> 2359 2360 2361 </DD> 2362 2363 <DT><b><a name="defer_transports">defer_transports</a> 2364 (default: empty)</b></DT><DD> 2365 2366 <p> 2367 The names of message delivery transports that should not deliver mail 2368 unless someone issues "<b>sendmail -q</b>" or equivalent. Specify zero 2369 or more names of mail delivery transports names that appear in the 2370 first field of <a href="master.5.html">master.cf</a>. 2371 </p> 2372 2373 <p> 2374 Example: 2375 </p> 2376 2377 <pre> 2378 <a href="postconf.5.html#defer_transports">defer_transports</a> = smtp 2379 </pre> 2380 2381 2382 </DD> 2383 2384 <DT><b><a name="delay_logging_resolution_limit">delay_logging_resolution_limit</a> 2385 (default: 2)</b></DT><DD> 2386 2387 <p> The maximal number of digits after the decimal point when logging 2388 sub-second delay values. Specify a number in the range 0..6. </p> 2389 2390 <p> Large delay values are rounded off to an integral number seconds; 2391 delay values below the <a href="postconf.5.html#delay_logging_resolution_limit">delay_logging_resolution_limit</a> are logged 2392 as "0", and small delay values are logged with at most two-digit 2393 precision. </p> 2394 2395 <p> The format of the "delays=a/b/c/d" logging is as follows: </p> 2396 2397 <ul> 2398 2399 <li> a = time from message arrival to last <a href="QSHAPE_README.html#active_queue">active queue</a> entry 2400 2401 <li> b = time from last <a href="QSHAPE_README.html#active_queue">active queue</a> entry to connection setup 2402 2403 <li> c = time in connection setup, including DNS, EHLO and STARTTLS 2404 2405 <li> d = time in message transmission 2406 2407 </ul> 2408 2409 <p> This feature is available in Postfix 2.3 and later. </p> 2410 2411 2412 </DD> 2413 2414 <DT><b><a name="delay_notice_recipient">delay_notice_recipient</a> 2415 (default: postmaster)</b></DT><DD> 2416 2417 <p> 2418 The recipient of postmaster notifications with the message headers 2419 of mail that cannot be delivered within $<a href="postconf.5.html#delay_warning_time">delay_warning_time</a> time 2420 units. </p> 2421 2422 <p> 2423 This feature is enabled with the <a href="postconf.5.html#delay_warning_time">delay_warning_time</a> parameter. 2424 </p> 2425 2426 2427 </DD> 2428 2429 <DT><b><a name="delay_warning_time">delay_warning_time</a> 2430 (default: 0h)</b></DT><DD> 2431 2432 <p> 2433 The time after which the sender receives the message headers of 2434 mail that is still queued. 2435 </p> 2436 2437 <p> 2438 To enable this feature, specify a non-zero time value (an integral 2439 value plus an optional one-letter suffix that specifies the time 2440 unit). 2441 </p> 2442 2443 <p> 2444 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 2445 The default time unit is h (hours). 2446 </p> 2447 2448 2449 </DD> 2450 2451 <DT><b><a name="deliver_lock_attempts">deliver_lock_attempts</a> 2452 (default: 20)</b></DT><DD> 2453 2454 <p> 2455 The maximal number of attempts to acquire an exclusive lock on a 2456 mailbox file or <a href="bounce.8.html">bounce(8)</a> logfile. 2457 </p> 2458 2459 2460 </DD> 2461 2462 <DT><b><a name="deliver_lock_delay">deliver_lock_delay</a> 2463 (default: 1s)</b></DT><DD> 2464 2465 <p> 2466 The time between attempts to acquire an exclusive lock on a mailbox 2467 file or <a href="bounce.8.html">bounce(8)</a> logfile. 2468 </p> 2469 2470 <p> 2471 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 2472 The default time unit is s (seconds). 2473 </p> 2474 2475 2476 </DD> 2477 2478 <DT><b><a name="destination_concurrency_feedback_debug">destination_concurrency_feedback_debug</a> 2479 (default: no)</b></DT><DD> 2480 2481 <p> Make the queue manager's feedback algorithm verbose for performance 2482 analysis purposes. </p> 2483 2484 <p> This feature is available in Postfix 2.5 and later. </p> 2485 2486 2487 </DD> 2488 2489 <DT><b><a name="detect_8bit_encoding_header">detect_8bit_encoding_header</a> 2490 (default: yes)</b></DT><DD> 2491 2492 <p> Automatically detect 8BITMIME body content by looking at 2493 Content-Transfer-Encoding: message headers; historically, this 2494 behavior was hard-coded to be "always on". </p> 2495 2496 <p> This feature is available in Postfix 2.5 and later. </p> 2497 2498 2499 </DD> 2500 2501 <DT><b><a name="disable_dns_lookups">disable_dns_lookups</a> 2502 (default: no)</b></DT><DD> 2503 2504 <p> 2505 Disable DNS lookups in the Postfix SMTP and LMTP clients. When 2506 disabled, hosts are looked up with the getaddrinfo() system 2507 library routine which normally also looks in /etc/hosts. 2508 </p> 2509 2510 <p> 2511 DNS lookups are enabled by default. 2512 </p> 2513 2514 2515 </DD> 2516 2517 <DT><b><a name="disable_mime_input_processing">disable_mime_input_processing</a> 2518 (default: no)</b></DT><DD> 2519 2520 <p> 2521 Turn off MIME processing while receiving mail. This means that no 2522 special treatment is given to Content-Type: message headers, and 2523 that all text after the initial message headers is considered to 2524 be part of the message body. 2525 </p> 2526 2527 <p> 2528 This feature is available in Postfix 2.0 and later. 2529 </p> 2530 2531 <p> 2532 Mime input processing is enabled by default, and is needed in order 2533 to recognize MIME headers in message content. 2534 </p> 2535 2536 2537 </DD> 2538 2539 <DT><b><a name="disable_mime_output_conversion">disable_mime_output_conversion</a> 2540 (default: no)</b></DT><DD> 2541 2542 <p> 2543 Disable the conversion of 8BITMIME format to 7BIT format. Mime 2544 output conversion is needed when the destination does not advertise 2545 8BITMIME support. 2546 </p> 2547 2548 <p> 2549 This feature is available in Postfix 2.0 and later. 2550 </p> 2551 2552 2553 </DD> 2554 2555 <DT><b><a name="disable_verp_bounces">disable_verp_bounces</a> 2556 (default: no)</b></DT><DD> 2557 2558 <p> 2559 Disable sending one bounce report per recipient. 2560 </p> 2561 2562 <p> 2563 The default, one per recipient, is what ezmlm needs. 2564 </p> 2565 2566 <p> 2567 This feature is available in Postfix 1.1 and later. 2568 </p> 2569 2570 2571 </DD> 2572 2573 <DT><b><a name="disable_vrfy_command">disable_vrfy_command</a> 2574 (default: no)</b></DT><DD> 2575 2576 <p> 2577 Disable the SMTP VRFY command. This stops some techniques used to 2578 harvest email addresses. 2579 </p> 2580 2581 <p> 2582 Example: 2583 </p> 2584 2585 <pre> 2586 <a href="postconf.5.html#disable_vrfy_command">disable_vrfy_command</a> = no 2587 </pre> 2588 2589 2590 </DD> 2591 2592 <DT><b><a name="dnsblog_reply_delay">dnsblog_reply_delay</a> 2593 (default: 0s)</b></DT><DD> 2594 2595 <p> A debugging aid to artifically delay DNS responses. </p> 2596 2597 <p> This feature is available in Postfix 2.8. </p> 2598 2599 2600 </DD> 2601 2602 <DT><b><a name="dnsblog_service_name">dnsblog_service_name</a> 2603 (default: dnsblog)</b></DT><DD> 2604 2605 <p> The name of the <a href="dnsblog.8.html">dnsblog(8)</a> service entry in <a href="master.5.html">master.cf</a>. This 2606 service performs DNS white/blacklist lookups. </p> 2607 2608 <p> This feature is available in Postfix 2.8 and later. </p> 2609 2610 2611 </DD> 2612 2613 <DT><b><a name="dont_remove">dont_remove</a> 2614 (default: 0)</b></DT><DD> 2615 2616 <p> 2617 Don't remove queue files and save them to the "saved" mail queue. 2618 This is a debugging aid. To inspect the envelope information and 2619 content of a Postfix queue file, use the <a href="postcat.1.html">postcat(1)</a> command. 2620 </p> 2621 2622 2623 </DD> 2624 2625 <DT><b><a name="double_bounce_sender">double_bounce_sender</a> 2626 (default: double-bounce)</b></DT><DD> 2627 2628 <p> The sender address of postmaster notifications that are generated 2629 by the mail system. All mail to this address is silently discarded, 2630 in order to terminate mail bounce loops. </p> 2631 2632 2633 </DD> 2634 2635 <DT><b><a name="duplicate_filter_limit">duplicate_filter_limit</a> 2636 (default: 1000)</b></DT><DD> 2637 2638 <p> The maximal number of addresses remembered by the address 2639 duplicate filter for <a href="aliases.5.html">aliases(5)</a> or <a href="virtual.5.html">virtual(5)</a> alias expansion, or 2640 for <a href="showq.8.html">showq(8)</a> queue displays. </p> 2641 2642 2643 </DD> 2644 2645 <DT><b><a name="empty_address_default_transport_maps_lookup_key">empty_address_default_transport_maps_lookup_key</a> 2646 (default: <>)</b></DT><DD> 2647 2648 <p> The <a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a> search string that 2649 will be used instead of the null sender address. </p> 2650 2651 <p> This feature is available in Postfix 2.7 and later. </p> 2652 2653 2654 </DD> 2655 2656 <DT><b><a name="empty_address_recipient">empty_address_recipient</a> 2657 (default: MAILER-DAEMON)</b></DT><DD> 2658 2659 <p> 2660 The recipient of mail addressed to the null address. Postfix does 2661 not accept such addresses in SMTP commands, but they may still be 2662 created locally as the result of configuration or software error. 2663 </p> 2664 2665 2666 </DD> 2667 2668 <DT><b><a name="empty_address_relayhost_maps_lookup_key">empty_address_relayhost_maps_lookup_key</a> 2669 (default: <>)</b></DT><DD> 2670 2671 <p> The <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> search string that will be 2672 used instead of the null sender address. </p> 2673 2674 <p> This feature is available in Postfix 2.5 and later. With 2675 earlier versions, <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> lookups were 2676 skipped for the null sender address. </p> 2677 2678 2679 </DD> 2680 2681 <DT><b><a name="enable_errors_to">enable_errors_to</a> 2682 (default: no)</b></DT><DD> 2683 2684 <p> Report mail delivery errors to the address specified with the 2685 non-standard Errors-To: message header, instead of the envelope 2686 sender address (this feature is removed with Postfix version 2.2, is 2687 turned off by default with Postfix version 2.1, and is always turned on 2688 with older Postfix versions). </p> 2689 2690 2691 </DD> 2692 2693 <DT><b><a name="enable_original_recipient">enable_original_recipient</a> 2694 (default: yes)</b></DT><DD> 2695 2696 <p> Enable support for the X-Original-To message header. This header 2697 is needed for multi-recipient mailboxes. </p> 2698 2699 <p> When this parameter is set to yes, the <a href="cleanup.8.html">cleanup(8)</a> daemon performs 2700 duplicate elimination on distinct pairs of (original recipient, 2701 rewritten recipient), and generates non-empty original recipient 2702 queue file records. </p> 2703 2704 <p> When this parameter is set to no, the <a href="cleanup.8.html">cleanup(8)</a> daemon performs 2705 duplicate elimination on the rewritten recipient address only, and 2706 generates empty original recipient queue file records. </p> 2707 2708 <p> This feature is available in Postfix 2.1 and later. With Postfix 2709 version 2.0, support for the X-Original-To message header is always turned 2710 on. Postfix versions before 2.0 have no support for the X-Original-To 2711 message header. </p> 2712 2713 2714 </DD> 2715 2716 <DT><b><a name="error_notice_recipient">error_notice_recipient</a> 2717 (default: postmaster)</b></DT><DD> 2718 2719 <p> The recipient of postmaster notifications about mail delivery 2720 problems that are caused by policy, resource, software or protocol 2721 errors. These notifications are enabled with the <a href="postconf.5.html#notify_classes">notify_classes</a> 2722 parameter. </p> 2723 2724 2725 </DD> 2726 2727 <DT><b><a name="error_service_name">error_service_name</a> 2728 (default: error)</b></DT><DD> 2729 2730 <p> 2731 The name of the <a href="error.8.html">error(8)</a> pseudo delivery agent. This service always 2732 returns mail as undeliverable. 2733 </p> 2734 2735 <p> 2736 This feature is available in Postfix 2.0 and later. 2737 </p> 2738 2739 2740 </DD> 2741 2742 <DT><b><a name="execution_directory_expansion_filter">execution_directory_expansion_filter</a> 2743 (default: see "postconf -d" output)</b></DT><DD> 2744 2745 <p> Restrict the characters that the <a href="local.8.html">local(8)</a> delivery agent allows 2746 in $name expansions of $<a href="postconf.5.html#command_execution_directory">command_execution_directory</a>. Characters 2747 outside the allowed set are replaced by underscores. </p> 2748 2749 <p> This feature is available in Postfix 2.2 and later. </p> 2750 2751 2752 </DD> 2753 2754 <DT><b><a name="expand_owner_alias">expand_owner_alias</a> 2755 (default: no)</b></DT><DD> 2756 2757 <p> 2758 When delivering to an alias "aliasname" that has an "owner-aliasname" 2759 companion alias, set the envelope sender address to the expansion 2760 of the "owner-aliasname" alias. Normally, Postfix sets the envelope 2761 sender address to the name of the "owner-aliasname" alias. 2762 </p> 2763 2764 2765 </DD> 2766 2767 <DT><b><a name="export_environment">export_environment</a> 2768 (default: see "postconf -d" output)</b></DT><DD> 2769 2770 <p> 2771 The list of environment variables that a Postfix process will export 2772 to non-Postfix processes. The TZ variable is needed for sane 2773 time keeping on System-V-ish systems. 2774 </p> 2775 2776 <p> 2777 Specify a list of names and/or name=value pairs, separated by 2778 whitespace or comma. The name=value form is supported with 2779 Postfix version 2.1 and later. 2780 </p> 2781 2782 <p> 2783 Example: 2784 </p> 2785 2786 <pre> 2787 <a href="postconf.5.html#export_environment">export_environment</a> = TZ PATH=/bin:/usr/bin 2788 </pre> 2789 2790 2791 </DD> 2792 2793 <DT><b><a name="extract_recipient_limit">extract_recipient_limit</a> 2794 (default: 10240)</b></DT><DD> 2795 2796 <p> 2797 The maximal number of recipient addresses that Postfix will extract 2798 from message headers when mail is submitted with "<b>sendmail -t</b>". 2799 </p> 2800 2801 <p> 2802 This feature was removed in Postfix version 2.1. 2803 </p> 2804 2805 2806 </DD> 2807 2808 <DT><b><a name="fallback_relay">fallback_relay</a> 2809 (default: empty)</b></DT><DD> 2810 2811 <p> 2812 Optional list of relay hosts for SMTP destinations that can't be 2813 found or that are unreachable. With Postfix 2.3 this parameter 2814 is renamed to <a href="postconf.5.html#smtp_fallback_relay">smtp_fallback_relay</a>. </p> 2815 2816 <p> 2817 By default, mail is returned to the sender when a destination is 2818 not found, and delivery is deferred when a destination is unreachable. 2819 </p> 2820 2821 <p> The fallback relays must be SMTP destinations. Specify a domain, 2822 host, host:port, [host]:port, [address] or [address]:port; the form 2823 [host] turns off MX lookups. If you specify multiple SMTP 2824 destinations, Postfix will try them in the specified order. </p> 2825 2826 <p> Note: before Postfix 2.2, do not use the <a href="postconf.5.html#fallback_relay">fallback_relay</a> feature 2827 when relaying mail 2828 for a backup or primary MX domain. Mail would loop between the 2829 Postfix MX host and the <a href="postconf.5.html#fallback_relay">fallback_relay</a> host when the final destination 2830 is unavailable. </p> 2831 2832 <ul> 2833 2834 <li> In <a href="postconf.5.html">main.cf</a> specify "<a href="postconf.5.html#relay_transport">relay_transport</a> = relay", 2835 2836 <li> In <a href="master.5.html">master.cf</a> specify "-o <a href="postconf.5.html#fallback_relay">fallback_relay</a> =" (i.e., empty) at 2837 the end of the <tt>relay</tt> entry. 2838 2839 <li> In transport maps, specify "relay:<i>nexthop...</i>" 2840 as the right-hand side for backup or primary MX domain entries. 2841 2842 </ul> 2843 2844 <p> Postfix version 2.2 and later will not use the <a href="postconf.5.html#fallback_relay">fallback_relay</a> feature 2845 for destinations that it is MX host for. 2846 </p> 2847 2848 2849 </DD> 2850 2851 <DT><b><a name="fallback_transport">fallback_transport</a> 2852 (default: empty)</b></DT><DD> 2853 2854 <p> 2855 Optional message delivery transport that the <a href="local.8.html">local(8)</a> delivery 2856 agent should use for names that are not found in the <a href="aliases.5.html">aliases(5)</a> 2857 or UNIX password database. 2858 </p> 2859 2860 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 2861 is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>, 2862 <a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>, 2863 <a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p> 2864 2865 2866 </DD> 2867 2868 <DT><b><a name="fallback_transport_maps">fallback_transport_maps</a> 2869 (default: empty)</b></DT><DD> 2870 2871 <p> Optional lookup tables with per-recipient message delivery 2872 transports for recipients that the <a href="local.8.html">local(8)</a> delivery agent could 2873 not find in the <a href="aliases.5.html">aliases(5)</a> or UNIX password database. </p> 2874 2875 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 2876 is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>, 2877 <a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>, 2878 <a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p> 2879 2880 <p> For safety reasons, this feature does not allow $number 2881 substitutions in regular expression maps. </p> 2882 2883 <p> This feature is available in Postfix 2.3 and later. </p> 2884 2885 2886 </DD> 2887 2888 <DT><b><a name="fast_flush_domains">fast_flush_domains</a> 2889 (default: $<a href="postconf.5.html#relay_domains">relay_domains</a>)</b></DT><DD> 2890 2891 <p> 2892 Optional list of destinations that are eligible for per-destination 2893 logfiles with mail that is queued to those destinations. 2894 </p> 2895 2896 <p> 2897 By default, Postfix maintains "fast flush" logfiles only for 2898 destinations that the Postfix SMTP server is willing to relay to 2899 (i.e. the default is: "<a href="postconf.5.html#fast_flush_domains">fast_flush_domains</a> = $<a href="postconf.5.html#relay_domains">relay_domains</a>"; see 2900 the <a href="postconf.5.html#relay_domains">relay_domains</a> parameter in the <a href="postconf.5.html">postconf(5)</a> manual). 2901 </p> 2902 2903 <p> Specify a list of hosts or domains, "/file/name" patterns or 2904 "<a href="DATABASE_README.html">type:table</a>" lookup tables, separated by commas and/or whitespace. 2905 Continue long lines by starting the next line with whitespace. A 2906 "/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" 2907 lookup table is matched when the domain or its parent domain appears 2908 as lookup key. </p> 2909 2910 <p> 2911 Specify "<a href="postconf.5.html#fast_flush_domains">fast_flush_domains</a> =" (i.e., empty) to disable the feature 2912 altogether. 2913 </p> 2914 2915 2916 </DD> 2917 2918 <DT><b><a name="fast_flush_purge_time">fast_flush_purge_time</a> 2919 (default: 7d)</b></DT><DD> 2920 2921 <p> 2922 The time after which an empty per-destination "fast flush" logfile 2923 is deleted. 2924 </p> 2925 2926 <p> 2927 You can specify the time as a number, or as a number followed by 2928 a letter that indicates the time unit: s=seconds, m=minutes, h=hours, 2929 d=days, w=weeks. The default time unit is days. 2930 </p> 2931 2932 2933 </DD> 2934 2935 <DT><b><a name="fast_flush_refresh_time">fast_flush_refresh_time</a> 2936 (default: 12h)</b></DT><DD> 2937 2938 <p> 2939 The time after which a non-empty but unread per-destination "fast 2940 flush" logfile needs to be refreshed. The contents of a logfile 2941 are refreshed by requesting delivery of all messages listed in the 2942 logfile. 2943 </p> 2944 2945 <p> 2946 You can specify the time as a number, or as a number followed by 2947 a letter that indicates the time unit: s=seconds, m=minutes, h=hours, 2948 d=days, w=weeks. The default time unit is hours. 2949 </p> 2950 2951 2952 </DD> 2953 2954 <DT><b><a name="fault_injection_code">fault_injection_code</a> 2955 (default: 0)</b></DT><DD> 2956 2957 <p> 2958 Force specific internal tests to fail, to test the handling of 2959 errors that are difficult to reproduce otherwise. 2960 </p> 2961 2962 2963 </DD> 2964 2965 <DT><b><a name="flush_service_name">flush_service_name</a> 2966 (default: flush)</b></DT><DD> 2967 2968 <p> 2969 The name of the <a href="flush.8.html">flush(8)</a> service. This service maintains per-destination 2970 logfiles with the queue file names of mail that is queued for those 2971 destinations. 2972 </p> 2973 2974 <p> 2975 This feature is available in Postfix 2.0 and later. 2976 </p> 2977 2978 2979 </DD> 2980 2981 <DT><b><a name="fork_attempts">fork_attempts</a> 2982 (default: 5)</b></DT><DD> 2983 2984 <p> The maximal number of attempts to fork() a child process. </p> 2985 2986 2987 </DD> 2988 2989 <DT><b><a name="fork_delay">fork_delay</a> 2990 (default: 1s)</b></DT><DD> 2991 2992 <p> The delay between attempts to fork() a child process. </p> 2993 2994 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 2995 (weeks). The default time unit is s (seconds). </p> 2996 2997 2998 </DD> 2999 3000 <DT><b><a name="forward_expansion_filter">forward_expansion_filter</a> 3001 (default: see "postconf -d" output)</b></DT><DD> 3002 3003 <p> 3004 Restrict the characters that the <a href="local.8.html">local(8)</a> delivery agent allows in 3005 $name expansions of $<a href="postconf.5.html#forward_path">forward_path</a>. Characters outside the 3006 allowed set are replaced by underscores. 3007 </p> 3008 3009 3010 </DD> 3011 3012 <DT><b><a name="forward_path">forward_path</a> 3013 (default: see "postconf -d" output)</b></DT><DD> 3014 3015 <p> The <a href="local.8.html">local(8)</a> delivery agent search list for finding a .forward 3016 file with user-specified delivery methods. The first file that is 3017 found is used. </p> 3018 3019 <p> The following $name expansions are done on <a href="postconf.5.html#forward_path">forward_path</a> before 3020 the search actually happens. The result of $name expansion is 3021 filtered with the character set that is specified with the 3022 <a href="postconf.5.html#forward_expansion_filter">forward_expansion_filter</a> parameter. </p> 3023 3024 <dl> 3025 3026 <dt><b>$user</b></dt> 3027 3028 <dd>The recipient's username. </dd> 3029 3030 <dt><b>$shell</b></dt> 3031 3032 <dd>The recipient's login shell pathname. </dd> 3033 3034 <dt><b>$home</b></dt> 3035 3036 <dd>The recipient's home directory. </dd> 3037 3038 <dt><b>$recipient</b></dt> 3039 3040 <dd>The full recipient address. </dd> 3041 3042 <dt><b>$extension</b></dt> 3043 3044 <dd>The optional recipient address extension. </dd> 3045 3046 <dt><b>$domain</b></dt> 3047 3048 <dd>The recipient domain. </dd> 3049 3050 <dt><b>$local</b></dt> 3051 3052 <dd>The entire recipient localpart. </dd> 3053 3054 <dt><b>$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b></dt> 3055 3056 <dd>The system-wide recipient address extension delimiter. </dd> 3057 3058 <dt><b>${name?value}</b></dt> 3059 3060 <dd>Expands to <i>value</i> when <i>$name</i> is non-empty. </dd> 3061 3062 <dt><b>${name:value}</b></dt> 3063 3064 <dd>Expands to <i>value</i> when <i>$name</i> is empty. </dd> 3065 3066 </dl> 3067 3068 <p> 3069 Instead of $name you can also specify ${name} or $(name). 3070 </p> 3071 3072 <p> 3073 Examples: 3074 </p> 3075 3076 <pre> 3077 <a href="postconf.5.html#forward_path">forward_path</a> = /var/forward/$user 3078 <a href="postconf.5.html#forward_path">forward_path</a> = 3079 /var/forward/$user/.forward$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a>$extension, 3080 /var/forward/$user/.forward 3081 </pre> 3082 3083 3084 </DD> 3085 3086 <DT><b><a name="frozen_delivered_to">frozen_delivered_to</a> 3087 (default: yes)</b></DT><DD> 3088 3089 <p> Update the <a href="local.8.html">local(8)</a> delivery agent's idea of the Delivered-To: 3090 address (see <a href="postconf.5.html#prepend_delivered_header">prepend_delivered_header</a>) only once, at the start of 3091 a delivery attempt; do not update the Delivered-To: address while 3092 expanding aliases or .forward files. </p> 3093 3094 <p> This feature is available in Postfix 2.3 and later. With older 3095 Postfix releases, the behavior is as if this parameter is set to 3096 "no". The old setting can be expensive with deeply nested aliases 3097 or .forward files. When an alias or .forward file changes the 3098 Delivered-To: address, it ties up one queue file and one cleanup 3099 process instance while mail is being forwarded. </p> 3100 3101 3102 </DD> 3103 3104 <DT><b><a name="hash_queue_depth">hash_queue_depth</a> 3105 (default: 1)</b></DT><DD> 3106 3107 <p> 3108 The number of subdirectory levels for queue directories listed with 3109 the <a href="postconf.5.html#hash_queue_names">hash_queue_names</a> parameter. 3110 </p> 3111 3112 <p> 3113 After changing the <a href="postconf.5.html#hash_queue_names">hash_queue_names</a> or <a href="postconf.5.html#hash_queue_depth">hash_queue_depth</a> parameter, 3114 execute the command "<b>postfix reload</b>". 3115 </p> 3116 3117 3118 </DD> 3119 3120 <DT><b><a name="hash_queue_names">hash_queue_names</a> 3121 (default: deferred, defer)</b></DT><DD> 3122 3123 <p> 3124 The names of queue directories that are split across multiple 3125 subdirectory levels. 3126 </p> 3127 3128 <p> Before Postfix version 2.2, the default list of hashed queues 3129 was significantly larger. Claims about improvements in file system 3130 technology suggest that hashing of the <a href="QSHAPE_README.html#incoming_queue">incoming</a> and <a href="QSHAPE_README.html#active_queue">active queues</a> 3131 is no longer needed. Fewer hashed directories speed up the time 3132 needed to restart Postfix. </p> 3133 3134 <p> 3135 After changing the <a href="postconf.5.html#hash_queue_names">hash_queue_names</a> or <a href="postconf.5.html#hash_queue_depth">hash_queue_depth</a> parameter, 3136 execute the command "<b>postfix reload</b>". 3137 </p> 3138 3139 3140 </DD> 3141 3142 <DT><b><a name="header_address_token_limit">header_address_token_limit</a> 3143 (default: 10240)</b></DT><DD> 3144 3145 <p> 3146 The maximal number of address tokens are allowed in an address 3147 message header. Information that exceeds the limit is discarded. 3148 The limit is enforced by the <a href="cleanup.8.html">cleanup(8)</a> server. 3149 </p> 3150 3151 3152 </DD> 3153 3154 <DT><b><a name="header_checks">header_checks</a> 3155 (default: empty)</b></DT><DD> 3156 3157 <p> 3158 Optional lookup tables for content inspection of primary non-MIME 3159 message headers, as specified in the <a href="header_checks.5.html">header_checks(5)</a> manual page. 3160 </p> 3161 3162 3163 </DD> 3164 3165 <DT><b><a name="header_size_limit">header_size_limit</a> 3166 (default: 102400)</b></DT><DD> 3167 3168 <p> 3169 The maximal amount of memory in bytes for storing a message header. 3170 If a header is larger, the excess is discarded. The limit is 3171 enforced by the <a href="cleanup.8.html">cleanup(8)</a> server. 3172 </p> 3173 3174 3175 </DD> 3176 3177 <DT><b><a name="helpful_warnings">helpful_warnings</a> 3178 (default: yes)</b></DT><DD> 3179 3180 <p> 3181 Log warnings about problematic configuration settings, and provide 3182 helpful suggestions. 3183 </p> 3184 3185 <p> 3186 This feature is available in Postfix 2.0 and later. 3187 </p> 3188 3189 3190 </DD> 3191 3192 <DT><b><a name="home_mailbox">home_mailbox</a> 3193 (default: empty)</b></DT><DD> 3194 3195 <p> 3196 Optional pathname of a mailbox file relative to a <a href="local.8.html">local(8)</a> user's 3197 home directory. 3198 </p> 3199 3200 <p> 3201 Specify a pathname ending in "/" for qmail-style delivery. 3202 </p> 3203 3204 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 3205 is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>, 3206 <a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>, 3207 <a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p> 3208 3209 <p> 3210 Examples: 3211 </p> 3212 3213 <pre> 3214 <a href="postconf.5.html#home_mailbox">home_mailbox</a> = Mailbox 3215 <a href="postconf.5.html#home_mailbox">home_mailbox</a> = Maildir/ 3216 </pre> 3217 3218 3219 </DD> 3220 3221 <DT><b><a name="hopcount_limit">hopcount_limit</a> 3222 (default: 50)</b></DT><DD> 3223 3224 <p> 3225 The maximal number of Received: message headers that is allowed 3226 in the primary message headers. A message that exceeds the limit 3227 is bounced, in order to stop a mailer loop. 3228 </p> 3229 3230 3231 </DD> 3232 3233 <DT><b><a name="html_directory">html_directory</a> 3234 (default: see "postconf -d" output)</b></DT><DD> 3235 3236 <p> 3237 The location of Postfix HTML files that describe how to build, 3238 configure or operate a specific Postfix subsystem or feature. 3239 </p> 3240 3241 3242 </DD> 3243 3244 <DT><b><a name="ignore_mx_lookup_error">ignore_mx_lookup_error</a> 3245 (default: no)</b></DT><DD> 3246 3247 <p> Ignore DNS MX lookups that produce no response. By default, 3248 the Postfix SMTP client defers delivery and tries again after some 3249 delay. This behavior is required by the SMTP standard. </p> 3250 3251 <p> 3252 Specify "<a href="postconf.5.html#ignore_mx_lookup_error">ignore_mx_lookup_error</a> = yes" to force a DNS A record 3253 lookup instead. This violates the SMTP standard and can result in 3254 mis-delivery of mail. 3255 </p> 3256 3257 3258 </DD> 3259 3260 <DT><b><a name="import_environment">import_environment</a> 3261 (default: see "postconf -d" output)</b></DT><DD> 3262 3263 <p> 3264 The list of environment parameters that a Postfix process will 3265 import from a non-Postfix parent process. Examples of relevant 3266 parameters: 3267 </p> 3268 3269 <dl> 3270 3271 <dt><b>TZ</b></dt> 3272 3273 <dd>Needed for sane time keeping on most System-V-ish systems. </dd> 3274 3275 <dt><b>DISPLAY</b></dt> 3276 3277 <dd>Needed for debugging Postfix daemons with an X-windows debugger. </dd> 3278 3279 <dt><b>XAUTHORITY</b></dt> 3280 3281 <dd>Needed for debugging Postfix daemons with an X-windows debugger. </dd> 3282 3283 <dt><b>MAIL_CONFIG</b></dt> 3284 3285 <dd>Needed to make "<b>postfix -c</b>" work. </dd> 3286 3287 </dl> 3288 3289 <p> Specify a list of names and/or name=value pairs, separated by 3290 whitespace or comma. The name=value form is supported with 3291 Postfix version 2.1 and later. </p> 3292 3293 3294 </DD> 3295 3296 <DT><b><a name="in_flow_delay">in_flow_delay</a> 3297 (default: 1s)</b></DT><DD> 3298 3299 <p> Time to pause before accepting a new message, when the message 3300 arrival rate exceeds the message delivery rate. This feature is 3301 turned on by default (it's disabled on SCO UNIX due to an SCO bug). 3302 </p> 3303 3304 <p> 3305 With the default 100 SMTP server process limit, "<a href="postconf.5.html#in_flow_delay">in_flow_delay</a> 3306 = 1s" limits the mail inflow to 100 messages per second above the 3307 number of messages delivered per second. 3308 </p> 3309 3310 <p> 3311 Specify 0 to disable the feature. Valid delays are 0..10. 3312 </p> 3313 3314 3315 </DD> 3316 3317 <DT><b><a name="inet_interfaces">inet_interfaces</a> 3318 (default: all)</b></DT><DD> 3319 3320 <p> The network interface addresses that this mail system receives 3321 mail on. Specify "all" to receive mail on all network 3322 interfaces (default), and "loopback-only" to receive mail 3323 on loopback network interfaces only (Postfix version 2.2 and later). The 3324 parameter also controls delivery of mail to <tt>user@[ip.address]</tt>. 3325 </p> 3326 3327 <p> 3328 Note 1: you need to stop and start Postfix when this parameter changes. 3329 </p> 3330 3331 <p> Note 2: address information may be enclosed inside <tt>[]</tt>, 3332 but this form is not required here. </p> 3333 3334 <p> When <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> specifies just one IPv4 and/or IPv6 address 3335 that is not a loopback address, the Postfix SMTP client will use 3336 this address as the IP source address for outbound mail. Support 3337 for IPv6 is available in Postfix version 2.2 and later. </p> 3338 3339 <p> 3340 On a multi-homed firewall with separate Postfix instances listening on the 3341 "inside" and "outside" interfaces, this can prevent each instance from 3342 being able to reach servers on the "other side" of the firewall. Setting 3343 <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a> to 0.0.0.0 avoids the potential problem for 3344 IPv4, and setting <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a> to :: solves the problem 3345 for IPv6. </p> 3346 3347 <p> 3348 A better solution for multi-homed firewalls is to leave <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> 3349 at the default value and instead use explicit IP addresses in 3350 the <a href="master.5.html">master.cf</a> SMTP server definitions. This preserves the Postfix 3351 SMTP client's 3352 loop detection, by ensuring that each side of the firewall knows that the 3353 other IP address is still the same host. Setting $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> to a 3354 single IPv4 and/or IPV6 address is primarily useful with virtual 3355 hosting of domains on 3356 secondary IP addresses, when each IP address serves a different domain 3357 (and has a different $<a href="postconf.5.html#myhostname">myhostname</a> setting). </p> 3358 3359 <p> 3360 See also the <a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> parameter, for network addresses that 3361 are forwarded to Postfix by way of a proxy or address translator. 3362 </p> 3363 3364 <p> 3365 Examples: 3366 </p> 3367 3368 <pre> 3369 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = all (DEFAULT) 3370 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = loopback-only (Postfix version 2.2 and later) 3371 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = 127.0.0.1 3372 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = 127.0.0.1, [::1] (Postfix version 2.2 and later) 3373 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = 192.168.1.2, 127.0.0.1 3374 </pre> 3375 3376 3377 </DD> 3378 3379 <DT><b><a name="inet_protocols">inet_protocols</a> 3380 (default: ipv4)</b></DT><DD> 3381 3382 <p> The Internet protocols Postfix will attempt to use when making 3383 or accepting connections. Specify one or more of "ipv4" 3384 or "ipv6", separated by whitespace or commas. The form 3385 "all" is equivalent to "ipv4, ipv6" or "ipv4", depending 3386 on whether the operating system implements IPv6. </p> 3387 3388 <p> This feature is available in Postfix 2.2 and later. </p> 3389 3390 <p> Note: you MUST stop and start Postfix after changing this 3391 parameter. </p> 3392 3393 <p> On systems that pre-date IPV6_V6ONLY support (<a href="http://tools.ietf.org/html/rfc3493">RFC 3493</a>), an 3394 IPv6 server will also accept IPv4 connections, even when IPv4 is 3395 turned off with the <a href="postconf.5.html#inet_protocols">inet_protocols</a> parameter. On systems with 3396 IPV6_V6ONLY support, Postfix will use separate server sockets for 3397 IPv6 and IPv4, and each will accept only connections for the 3398 corresponding protocol. </p> 3399 3400 <p> When IPv4 support is enabled via the <a href="postconf.5.html#inet_protocols">inet_protocols</a> parameter, 3401 Postfix will to DNS type A record lookups, and will convert 3402 IPv4-in-IPv6 client IP addresses (::ffff:1.2.3.4) to their original 3403 IPv4 form (1.2.3.4). The latter is needed on hosts that pre-date 3404 IPV6_V6ONLY support (<a href="http://tools.ietf.org/html/rfc3493">RFC 3493</a>). </p> 3405 3406 <p> When IPv6 support is enabled via the <a href="postconf.5.html#inet_protocols">inet_protocols</a> parameter, 3407 Postfix will do DNS type AAAA record lookups. </p> 3408 3409 <p> When both IPv4 and IPv6 support are enabled, the Postfix SMTP 3410 client will attempt to connect via IPv6 before attempting to use 3411 IPv4. </p> 3412 3413 <p> 3414 Examples: 3415 </p> 3416 3417 <pre> 3418 <a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv4 (DEFAULT) 3419 <a href="postconf.5.html#inet_protocols">inet_protocols</a> = all 3420 <a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv6 3421 <a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv4, ipv6 3422 </pre> 3423 3424 3425 </DD> 3426 3427 <DT><b><a name="initial_destination_concurrency">initial_destination_concurrency</a> 3428 (default: 5)</b></DT><DD> 3429 3430 <p> 3431 The initial per-destination concurrency level for parallel delivery 3432 to the same destination. 3433 With per-destination recipient limit > 1, a destination is a domain, 3434 otherwise it is a recipient. 3435 </p> 3436 3437 <p> Use <a href="postconf.5.html#transport_initial_destination_concurrency"><i>transport</i>_initial_destination_concurrency</a> to specify 3438 a transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 3439 name of the message delivery transport (Postfix 2.5 and later). </p> 3440 3441 <p> 3442 Warning: with concurrency of 1, one bad message can be enough to 3443 block all mail to a site. 3444 </p> 3445 3446 3447 </DD> 3448 3449 <DT><b><a name="internal_mail_filter_classes">internal_mail_filter_classes</a> 3450 (default: empty)</b></DT><DD> 3451 3452 <p> What categories of Postfix-generated mail are subject to 3453 before-queue content inspection by <a href="postconf.5.html#non_smtpd_milters">non_smtpd_milters</a>, <a href="postconf.5.html#header_checks">header_checks</a> 3454 and <a href="postconf.5.html#body_checks">body_checks</a>. Specify zero or more of the following, separated 3455 by whitespace or comma. </p> 3456 3457 <dl> 3458 3459 <dt><b>bounce</b></dt> <dd> Inspect the content of delivery 3460 status notifications. </dd> 3461 3462 <dt><b>notify</b></dt> <dd> Inspect the content of postmaster 3463 notifications by the <a href="smtp.8.html">smtp(8)</a> and <a href="smtpd.8.html">smtpd(8)</a> processes. </dd> 3464 3465 </dl> 3466 3467 <p> NOTE: It's generally not safe to enable content inspection of 3468 Postfix-generated email messages. The user is warned. </p> 3469 3470 <p> This feature is available in Postfix 2.3 and later. </p> 3471 3472 3473 </DD> 3474 3475 <DT><b><a name="invalid_hostname_reject_code">invalid_hostname_reject_code</a> 3476 (default: 501)</b></DT><DD> 3477 3478 <p> 3479 The numerical Postfix SMTP server response code when the client 3480 HELO or EHLO command parameter is rejected by the <a href="postconf.5.html#reject_invalid_helo_hostname">reject_invalid_helo_hostname</a> 3481 restriction. 3482 </p> 3483 3484 <p> 3485 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 3486 </p> 3487 3488 3489 </DD> 3490 3491 <DT><b><a name="ipc_idle">ipc_idle</a> 3492 (default: version dependent)</b></DT><DD> 3493 3494 <p> 3495 The time after which a client closes an idle internal communication 3496 channel. The purpose is to allow servers to terminate voluntarily 3497 after they become idle. This is used, for example, by the address 3498 resolving and rewriting clients. 3499 </p> 3500 3501 <p> With Postfix 2.4 the default value was reduced from 100s to 5s. </p> 3502 3503 <p> 3504 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3505 The default time unit is s (seconds). 3506 </p> 3507 3508 3509 </DD> 3510 3511 <DT><b><a name="ipc_timeout">ipc_timeout</a> 3512 (default: 3600s)</b></DT><DD> 3513 3514 <p> 3515 The time limit for sending or receiving information over an internal 3516 communication channel. The purpose is to break out of deadlock 3517 situations. If the time limit is exceeded the software aborts with a 3518 fatal error. 3519 </p> 3520 3521 <p> 3522 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3523 The default time unit is s (seconds). 3524 </p> 3525 3526 3527 </DD> 3528 3529 <DT><b><a name="ipc_ttl">ipc_ttl</a> 3530 (default: 1000s)</b></DT><DD> 3531 3532 <p> 3533 The time after which a client closes an active internal communication 3534 channel. The purpose is to allow servers to terminate voluntarily 3535 after reaching their client limit. This is used, for example, by 3536 the address resolving and rewriting clients. 3537 </p> 3538 3539 <p> 3540 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3541 The default time unit is s (seconds). 3542 </p> 3543 3544 <p> 3545 This feature is available in Postfix 2.1 and later. 3546 </p> 3547 3548 3549 </DD> 3550 3551 <DT><b><a name="line_length_limit">line_length_limit</a> 3552 (default: 2048)</b></DT><DD> 3553 3554 <p> Upon input, long lines are chopped up into pieces of at most 3555 this length; upon delivery, long lines are reconstructed. </p> 3556 3557 3558 </DD> 3559 3560 <DT><b><a name="lmtp_address_preference">lmtp_address_preference</a> 3561 (default: ipv6)</b></DT><DD> 3562 3563 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_address_preference">smtp_address_preference</a> 3564 configuration parameter. See there for details. </p> 3565 3566 <p> This feature is available in Postfix 2.8 and later. </p> 3567 3568 3569 </DD> 3570 3571 <DT><b><a name="lmtp_assume_final">lmtp_assume_final</a> 3572 (default: no)</b></DT><DD> 3573 3574 <p> When an LMTP server announces no DSN support, assume that the 3575 server performs final delivery, and send "delivered" delivery status 3576 notifications instead of "relayed". The default setting is backwards 3577 compatible to avoid the infinetisimal possibility of breaking 3578 existing LMTP-based content filters. </p> 3579 3580 3581 </DD> 3582 3583 <DT><b><a name="lmtp_bind_address">lmtp_bind_address</a> 3584 (default: empty)</b></DT><DD> 3585 3586 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a> configuration 3587 parameter. See there for details. </p> 3588 3589 <p> This feature is available in Postfix 2.3 and later. </p> 3590 3591 3592 </DD> 3593 3594 <DT><b><a name="lmtp_bind_address6">lmtp_bind_address6</a> 3595 (default: empty)</b></DT><DD> 3596 3597 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a> configuration 3598 parameter. See there for details. </p> 3599 3600 <p> This feature is available in Postfix 2.3 and later. </p> 3601 3602 3603 </DD> 3604 3605 <DT><b><a name="lmtp_body_checks">lmtp_body_checks</a> 3606 (default: empty)</b></DT><DD> 3607 3608 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_body_checks">smtp_body_checks</a> configuration 3609 parameter. See there for details. </p> 3610 3611 <p> This feature is available in Postfix 2.5 and later. </p> 3612 3613 3614 </DD> 3615 3616 <DT><b><a name="lmtp_cache_connection">lmtp_cache_connection</a> 3617 (default: yes)</b></DT><DD> 3618 3619 <p> 3620 Keep Postfix LMTP client connections open for up to $<a href="postconf.5.html#max_idle">max_idle</a> 3621 seconds. When the LMTP client receives a request for the same 3622 connection the connection is reused. 3623 </p> 3624 3625 <p> This parameter is available in Postfix version 2.2 and earlier. 3626 With Postfix version 2.3 and later, see <a href="postconf.5.html#lmtp_connection_cache_on_demand">lmtp_connection_cache_on_demand</a>, 3627 <a href="postconf.5.html#lmtp_connection_cache_destinations">lmtp_connection_cache_destinations</a>, or <a href="postconf.5.html#lmtp_connection_reuse_time_limit">lmtp_connection_reuse_time_limit</a>. 3628 </p> 3629 3630 <p> 3631 The effectiveness of cached connections will be determined by the 3632 number of LMTP servers in use, and the concurrency limit specified 3633 for the LMTP client. Cached connections are closed under any of 3634 the following conditions: 3635 </p> 3636 3637 <ul> 3638 3639 <li> The LMTP client idle time limit is reached. This limit is 3640 specified with the Postfix <a href="postconf.5.html#max_idle">max_idle</a> configuration parameter. 3641 3642 <li> A delivery request specifies a different destination than the 3643 one currently cached. 3644 3645 <li> The per-process limit on the number of delivery requests is 3646 reached. This limit is specified with the Postfix <a href="postconf.5.html#max_use">max_use</a> 3647 configuration parameter. 3648 3649 <li> Upon the onset of another delivery request, the LMTP server 3650 associated with the current session does not respond to the RSET 3651 command. 3652 3653 </ul> 3654 3655 <p> 3656 Most of these limitations will be removed after Postfix implements 3657 a connection cache that is shared among multiple LMTP client 3658 programs. 3659 </p> 3660 3661 3662 </DD> 3663 3664 <DT><b><a name="lmtp_cname_overrides_servername">lmtp_cname_overrides_servername</a> 3665 (default: yes)</b></DT><DD> 3666 3667 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_cname_overrides_servername">smtp_cname_overrides_servername</a> 3668 configuration parameter. See there for details. </p> 3669 3670 <p> This feature is available in Postfix 2.3 and later. </p> 3671 3672 3673 </DD> 3674 3675 <DT><b><a name="lmtp_connect_timeout">lmtp_connect_timeout</a> 3676 (default: 0s)</b></DT><DD> 3677 3678 <p> The LMTP client time limit for completing a TCP connection, or 3679 zero (use the operating system built-in time limit). When no 3680 connection can be made within the deadline, the LMTP client tries 3681 the next address on the mail exchanger list. </p> 3682 3683 <p> 3684 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3685 The default time unit is s (seconds). 3686 </p> 3687 3688 <p> 3689 Example: 3690 </p> 3691 3692 <pre> 3693 <a href="postconf.5.html#lmtp_connect_timeout">lmtp_connect_timeout</a> = 30s 3694 </pre> 3695 3696 3697 </DD> 3698 3699 <DT><b><a name="lmtp_connection_cache_destinations">lmtp_connection_cache_destinations</a> 3700 (default: empty)</b></DT><DD> 3701 3702 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_cache_destinations">smtp_connection_cache_destinations</a> 3703 configuration parameter. See there for details. </p> 3704 3705 <p> This feature is available in Postfix 2.3 and later. </p> 3706 3707 3708 </DD> 3709 3710 <DT><b><a name="lmtp_connection_cache_on_demand">lmtp_connection_cache_on_demand</a> 3711 (default: yes)</b></DT><DD> 3712 3713 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_cache_on_demand">smtp_connection_cache_on_demand</a> 3714 configuration parameter. See there for details. </p> 3715 3716 <p> This feature is available in Postfix 2.3 and later. </p> 3717 3718 3719 </DD> 3720 3721 <DT><b><a name="lmtp_connection_cache_time_limit">lmtp_connection_cache_time_limit</a> 3722 (default: 2s)</b></DT><DD> 3723 3724 <p> The LMTP-specific version of the 3725 <a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> configuration parameter. 3726 See there for details. </p> 3727 3728 <p> This feature is available in Postfix 2.3 and later. </p> 3729 3730 3731 </DD> 3732 3733 <DT><b><a name="lmtp_connection_reuse_time_limit">lmtp_connection_reuse_time_limit</a> 3734 (default: 300s)</b></DT><DD> 3735 3736 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a> 3737 configuration parameter. See there for details. </p> 3738 3739 <p> This feature is available in Postfix 2.3 and later. </p> 3740 3741 3742 </DD> 3743 3744 <DT><b><a name="lmtp_data_done_timeout">lmtp_data_done_timeout</a> 3745 (default: 600s)</b></DT><DD> 3746 3747 <p> The LMTP client time limit for sending the LMTP ".", and for 3748 receiving the server response. When no response is received within 3749 the deadline, a warning is logged that the mail may be delivered 3750 multiple times. </p> 3751 3752 <p> 3753 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3754 The default time unit is s (seconds). 3755 </p> 3756 3757 3758 </DD> 3759 3760 <DT><b><a name="lmtp_data_init_timeout">lmtp_data_init_timeout</a> 3761 (default: 120s)</b></DT><DD> 3762 3763 <p> 3764 The LMTP client time limit for sending the LMTP DATA command, and 3765 for receiving the server response. 3766 </p> 3767 3768 <p> 3769 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3770 The default time unit is s (seconds). 3771 </p> 3772 3773 3774 </DD> 3775 3776 <DT><b><a name="lmtp_data_xfer_timeout">lmtp_data_xfer_timeout</a> 3777 (default: 180s)</b></DT><DD> 3778 3779 <p> 3780 The LMTP client time limit for sending the LMTP message content. 3781 When the connection stalls for more than $<a href="postconf.5.html#lmtp_data_xfer_timeout">lmtp_data_xfer_timeout</a> 3782 the LMTP client terminates the transfer. 3783 </p> 3784 3785 <p> 3786 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3787 The default time unit is s (seconds). 3788 </p> 3789 3790 3791 </DD> 3792 3793 <DT><b><a name="lmtp_defer_if_no_mx_address_found">lmtp_defer_if_no_mx_address_found</a> 3794 (default: no)</b></DT><DD> 3795 3796 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_defer_if_no_mx_address_found">smtp_defer_if_no_mx_address_found</a> 3797 configuration parameter. See there for details. </p> 3798 3799 <p> This feature is available in Postfix 2.3 and later. </p> 3800 3801 3802 </DD> 3803 3804 <DT><b><a name="lmtp_destination_concurrency_limit">lmtp_destination_concurrency_limit</a> 3805 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 3806 3807 <p> The maximal number of parallel deliveries to the same destination 3808 via the lmtp message delivery transport. This limit is enforced by 3809 the queue manager. The message delivery transport name is the first 3810 field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 3811 3812 3813 </DD> 3814 3815 <DT><b><a name="lmtp_destination_recipient_limit">lmtp_destination_recipient_limit</a> 3816 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 3817 3818 <p> The maximal number of recipients per message for the lmtp 3819 message delivery transport. This limit is enforced by the queue 3820 manager. The message delivery transport name is the first field in 3821 the entry in the <a href="master.5.html">master.cf</a> file. </p> 3822 3823 <p> Setting this parameter to a value of 1 changes the meaning of 3824 <a href="postconf.5.html#lmtp_destination_concurrency_limit">lmtp_destination_concurrency_limit</a> from concurrency per domain into 3825 concurrency per recipient. </p> 3826 3827 3828 </DD> 3829 3830 <DT><b><a name="lmtp_discard_lhlo_keyword_address_maps">lmtp_discard_lhlo_keyword_address_maps</a> 3831 (default: empty)</b></DT><DD> 3832 3833 <p> Lookup tables, indexed by the remote LMTP server address, with 3834 case insensitive lists of LHLO keywords (pipelining, starttls, 3835 auth, etc.) that the LMTP client will ignore in the LHLO response 3836 from a remote LMTP server. See <a href="postconf.5.html#lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a> for 3837 details. The table is not indexed by hostname for consistency with 3838 <a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a>. </p> 3839 3840 <p> This feature is available in Postfix 2.3 and later. </p> 3841 3842 3843 </DD> 3844 3845 <DT><b><a name="lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a> 3846 (default: empty)</b></DT><DD> 3847 3848 <p> A case insensitive list of LHLO keywords (pipelining, starttls, 3849 auth, etc.) that the LMTP client will ignore in the LHLO response 3850 from a remote LMTP server. </p> 3851 3852 <p> This feature is available in Postfix 2.3 and later. </p> 3853 3854 <p> Notes: </p> 3855 3856 <ul> 3857 3858 <li> <p> Specify the <b>silent-discard</b> pseudo keyword to prevent 3859 this action from being logged. </p> 3860 3861 <li> <p> Use the <a href="postconf.5.html#lmtp_discard_lhlo_keyword_address_maps">lmtp_discard_lhlo_keyword_address_maps</a> feature to 3862 discard LHLO keywords selectively. </p> 3863 3864 </ul> 3865 3866 3867 </DD> 3868 3869 <DT><b><a name="lmtp_dns_resolver_options">lmtp_dns_resolver_options</a> 3870 (default: empty)</b></DT><DD> 3871 3872 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_dns_resolver_options">smtp_dns_resolver_options</a> 3873 configuration parameter. See there for details. </p> 3874 3875 <p> This feature is available in Postfix 2.8 and later. </p> 3876 3877 3878 </DD> 3879 3880 <DT><b><a name="lmtp_enforce_tls">lmtp_enforce_tls</a> 3881 (default: no)</b></DT><DD> 3882 3883 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a> configuration 3884 parameter. See there for details. </p> 3885 3886 <p> This feature is available in Postfix 2.3 and later. </p> 3887 3888 3889 </DD> 3890 3891 <DT><b><a name="lmtp_generic_maps">lmtp_generic_maps</a> 3892 (default: empty)</b></DT><DD> 3893 3894 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_generic_maps">smtp_generic_maps</a> configuration 3895 parameter. See there for details. </p> 3896 3897 <p> This feature is available in Postfix 2.3 and later. </p> 3898 3899 3900 </DD> 3901 3902 <DT><b><a name="lmtp_header_checks">lmtp_header_checks</a> 3903 (default: empty)</b></DT><DD> 3904 3905 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_header_checks">smtp_header_checks</a> configuration 3906 parameter. See there for details. </p> 3907 3908 <p> This feature is available in Postfix 2.5 and later. </p> 3909 3910 3911 </DD> 3912 3913 <DT><b><a name="lmtp_host_lookup">lmtp_host_lookup</a> 3914 (default: dns)</b></DT><DD> 3915 3916 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_host_lookup">smtp_host_lookup</a> configuration 3917 parameter. See there for details. </p> 3918 3919 <p> This feature is available in Postfix 2.3 and later. </p> 3920 3921 3922 </DD> 3923 3924 <DT><b><a name="lmtp_lhlo_name">lmtp_lhlo_name</a> 3925 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 3926 3927 <p> 3928 The hostname to send in the LMTP LHLO command. 3929 </p> 3930 3931 <p> 3932 The default value is the machine hostname. Specify a hostname or 3933 [ip.add.re.ss]. 3934 </p> 3935 3936 <p> 3937 This information can be specified in the <a href="postconf.5.html">main.cf</a> file for all LMTP 3938 clients, or it can be specified in the <a href="master.5.html">master.cf</a> file for a specific 3939 client, for example: 3940 </p> 3941 3942 <blockquote> 3943 <pre> 3944 /etc/postfix/<a href="master.5.html">master.cf</a>: 3945 mylmtp ... lmtp -o <a href="postconf.5.html#lmtp_lhlo_name">lmtp_lhlo_name</a>=foo.bar.com 3946 </pre> 3947 </blockquote> 3948 3949 <p> 3950 This feature is available in Postfix 2.3 and later. 3951 </p> 3952 3953 3954 </DD> 3955 3956 <DT><b><a name="lmtp_lhlo_timeout">lmtp_lhlo_timeout</a> 3957 (default: 300s)</b></DT><DD> 3958 3959 <p> The LMTP client time limit for sending the LHLO command, and 3960 for receiving the initial server response. </p> 3961 3962 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 3963 (weeks). The default time unit is s (seconds). </p> 3964 3965 3966 </DD> 3967 3968 <DT><b><a name="lmtp_line_length_limit">lmtp_line_length_limit</a> 3969 (default: 990)</b></DT><DD> 3970 3971 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_line_length_limit">smtp_line_length_limit</a> 3972 configuration parameter. See there for details. </p> 3973 3974 <p> This feature is available in Postfix 2.3 and later. </p> 3975 3976 3977 </DD> 3978 3979 <DT><b><a name="lmtp_mail_timeout">lmtp_mail_timeout</a> 3980 (default: 300s)</b></DT><DD> 3981 3982 <p> 3983 The LMTP client time limit for sending the MAIL FROM command, and 3984 for receiving the server response. 3985 </p> 3986 3987 <p> 3988 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3989 The default time unit is s (seconds). 3990 </p> 3991 3992 3993 </DD> 3994 3995 <DT><b><a name="lmtp_mime_header_checks">lmtp_mime_header_checks</a> 3996 (default: empty)</b></DT><DD> 3997 3998 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_mime_header_checks">smtp_mime_header_checks</a> 3999 configuration parameter. See there for details. </p> 4000 4001 <p> This feature is available in Postfix 2.5 and later. </p> 4002 4003 4004 </DD> 4005 4006 <DT><b><a name="lmtp_mx_address_limit">lmtp_mx_address_limit</a> 4007 (default: 5)</b></DT><DD> 4008 4009 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_mx_address_limit">smtp_mx_address_limit</a> configuration 4010 parameter. See there for details. </p> 4011 4012 <p> This feature is available in Postfix 2.3 and later. </p> 4013 4014 4015 </DD> 4016 4017 <DT><b><a name="lmtp_mx_session_limit">lmtp_mx_session_limit</a> 4018 (default: 2)</b></DT><DD> 4019 4020 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_mx_session_limit">smtp_mx_session_limit</a> configuration 4021 parameter. See there for details. </p> 4022 4023 <p> This feature is available in Postfix 2.3 and later. </p> 4024 4025 4026 </DD> 4027 4028 <DT><b><a name="lmtp_nested_header_checks">lmtp_nested_header_checks</a> 4029 (default: empty)</b></DT><DD> 4030 4031 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_nested_header_checks">smtp_nested_header_checks</a> 4032 configuration parameter. See there for details. </p> 4033 4034 <p> This feature is available in Postfix 2.5 and later. </p> 4035 4036 4037 </DD> 4038 4039 <DT><b><a name="lmtp_pix_workaround_delay_time">lmtp_pix_workaround_delay_time</a> 4040 (default: 10s)</b></DT><DD> 4041 4042 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a> 4043 configuration parameter. See there for details. </p> 4044 4045 <p> This feature is available in Postfix 2.3 and later. </p> 4046 4047 4048 </DD> 4049 4050 <DT><b><a name="lmtp_pix_workaround_maps">lmtp_pix_workaround_maps</a> 4051 (default: empty)</b></DT><DD> 4052 4053 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_pix_workaround_maps">smtp_pix_workaround_maps</a> 4054 configuration parameter. See there for details. </p> 4055 4056 <p> This feature is available in Postfix 2.4 and later. </p> 4057 4058 4059 </DD> 4060 4061 <DT><b><a name="lmtp_pix_workaround_threshold_time">lmtp_pix_workaround_threshold_time</a> 4062 (default: 500s)</b></DT><DD> 4063 4064 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a> 4065 configuration parameter. See there for details. </p> 4066 4067 <p> This feature is available in Postfix 2.3 and later. </p> 4068 4069 4070 </DD> 4071 4072 <DT><b><a name="lmtp_pix_workarounds">lmtp_pix_workarounds</a> 4073 (default: empty)</b></DT><DD> 4074 4075 <p> The LMTP-specific version of the smtp_pix_workaround 4076 configuration parameter. See there for details. </p> 4077 4078 <p> This feature is available in Postfix 2.4 and later. </p> 4079 4080 4081 </DD> 4082 4083 <DT><b><a name="lmtp_quit_timeout">lmtp_quit_timeout</a> 4084 (default: 300s)</b></DT><DD> 4085 4086 <p> 4087 The LMTP client time limit for sending the QUIT command, and for 4088 receiving the server response. 4089 </p> 4090 4091 <p> 4092 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 4093 The default time unit is s (seconds). 4094 </p> 4095 4096 4097 </DD> 4098 4099 <DT><b><a name="lmtp_quote_rfc821_envelope">lmtp_quote_rfc821_envelope</a> 4100 (default: yes)</b></DT><DD> 4101 4102 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a> 4103 configuration parameter. See there for details. </p> 4104 4105 <p> This feature is available in Postfix 2.3 and later. </p> 4106 4107 4108 </DD> 4109 4110 <DT><b><a name="lmtp_randomize_addresses">lmtp_randomize_addresses</a> 4111 (default: yes)</b></DT><DD> 4112 4113 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_randomize_addresses">smtp_randomize_addresses</a> 4114 configuration parameter. See there for details. </p> 4115 4116 <p> This feature is available in Postfix 2.3 and later. </p> 4117 4118 4119 </DD> 4120 4121 <DT><b><a name="lmtp_rcpt_timeout">lmtp_rcpt_timeout</a> 4122 (default: 300s)</b></DT><DD> 4123 4124 <p> 4125 The LMTP client time limit for sending the RCPT TO command, and 4126 for receiving the server response. 4127 </p> 4128 4129 <p> 4130 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 4131 The default time unit is s (seconds). 4132 </p> 4133 4134 4135 </DD> 4136 4137 <DT><b><a name="lmtp_reply_filter">lmtp_reply_filter</a> 4138 (default: empty)</b></DT><DD> 4139 4140 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_reply_filter">smtp_reply_filter</a> 4141 configuration parameter. See there for details. </p> 4142 4143 <p> This feature is available in Postfix 2.7 and later. </p> 4144 4145 4146 </DD> 4147 4148 <DT><b><a name="lmtp_rset_timeout">lmtp_rset_timeout</a> 4149 (default: 20s)</b></DT><DD> 4150 4151 <p> The LMTP client time limit for sending the RSET command, and 4152 for receiving the server response. The LMTP client sends RSET in 4153 order to finish a recipient address probe, or to verify that a 4154 cached connection is still alive. </p> 4155 4156 <p> 4157 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 4158 The default time unit is s (seconds). 4159 </p> 4160 4161 4162 </DD> 4163 4164 <DT><b><a name="lmtp_sasl_auth_cache_name">lmtp_sasl_auth_cache_name</a> 4165 (default: empty)</b></DT><DD> 4166 4167 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> 4168 configuration parameter. See there for details. </p> 4169 4170 <p> This feature is available in Postfix 2.5 and later. </p> 4171 4172 4173 </DD> 4174 4175 <DT><b><a name="lmtp_sasl_auth_cache_time">lmtp_sasl_auth_cache_time</a> 4176 (default: 90d)</b></DT><DD> 4177 4178 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_auth_cache_time">smtp_sasl_auth_cache_time</a> 4179 configuration parameter. See there for details. </p> 4180 4181 <p> This feature is available in Postfix 2.5 and later. </p> 4182 4183 4184 </DD> 4185 4186 <DT><b><a name="lmtp_sasl_auth_enable">lmtp_sasl_auth_enable</a> 4187 (default: no)</b></DT><DD> 4188 4189 <p> 4190 Enable SASL authentication in the Postfix LMTP client. 4191 </p> 4192 4193 4194 </DD> 4195 4196 <DT><b><a name="lmtp_sasl_auth_soft_bounce">lmtp_sasl_auth_soft_bounce</a> 4197 (default: yes)</b></DT><DD> 4198 4199 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> 4200 configuration parameter. See there for details. </p> 4201 4202 <p> This feature is available in Postfix 2.5 and later. </p> 4203 4204 4205 </DD> 4206 4207 <DT><b><a name="lmtp_sasl_mechanism_filter">lmtp_sasl_mechanism_filter</a> 4208 (default: empty)</b></DT><DD> 4209 4210 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> 4211 configuration parameter. See there for details. </p> 4212 4213 <p> This feature is available in Postfix 2.3 and later. </p> 4214 4215 4216 </DD> 4217 4218 <DT><b><a name="lmtp_sasl_password_maps">lmtp_sasl_password_maps</a> 4219 (default: empty)</b></DT><DD> 4220 4221 <p> 4222 Optional LMTP client lookup tables with one username:password entry 4223 per host or domain. If a remote host or domain has no username:password 4224 entry, then the Postfix LMTP client will not attempt to authenticate 4225 to the remote host. 4226 </p> 4227 4228 4229 </DD> 4230 4231 <DT><b><a name="lmtp_sasl_path">lmtp_sasl_path</a> 4232 (default: empty)</b></DT><DD> 4233 4234 <p> Implementation-specific information that is passed through to 4235 the SASL plug-in implementation that is selected with 4236 <b><a href="postconf.5.html#lmtp_sasl_type">lmtp_sasl_type</a></b>. Typically this specifies the name of a 4237 configuration file or rendezvous point. </p> 4238 4239 <p> This feature is available in Postfix 2.3 and later. </p> 4240 4241 4242 </DD> 4243 4244 <DT><b><a name="lmtp_sasl_security_options">lmtp_sasl_security_options</a> 4245 (default: noplaintext, noanonymous)</b></DT><DD> 4246 4247 <p> SASL security options; as of Postfix 2.3 the list of available 4248 features depends on the SASL client implementation that is selected 4249 with <b><a href="postconf.5.html#lmtp_sasl_type">lmtp_sasl_type</a></b>. </p> 4250 4251 <p> The following security features are defined for the <b>cyrus</b> 4252 client SASL implementation: </p> 4253 4254 <dl> 4255 4256 <dt><b>noplaintext</b></dt> 4257 4258 <dd>Disallow authentication methods that use plaintext passwords. </dd> 4259 4260 <dt><b>noactive</b></dt> 4261 4262 <dd>Disallow authentication methods that are vulnerable to non-dictionary 4263 active attacks. </dd> 4264 4265 <dt><b>nodictionary</b></dt> 4266 4267 <dd>Disallow authentication methods that are vulnerable to passive 4268 dictionary attack. </dd> 4269 4270 <dt><b>noanonymous</b></dt> 4271 4272 <dd>Disallow anonymous logins. </dd> 4273 4274 </dl> 4275 4276 <p> 4277 Example: 4278 </p> 4279 4280 <pre> 4281 <a href="postconf.5.html#lmtp_sasl_security_options">lmtp_sasl_security_options</a> = noplaintext 4282 </pre> 4283 4284 4285 </DD> 4286 4287 <DT><b><a name="lmtp_sasl_tls_security_options">lmtp_sasl_tls_security_options</a> 4288 (default: $<a href="postconf.5.html#lmtp_sasl_security_options">lmtp_sasl_security_options</a>)</b></DT><DD> 4289 4290 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a> 4291 configuration parameter. See there for details. </p> 4292 4293 <p> This feature is available in Postfix 2.3 and later. </p> 4294 4295 4296 </DD> 4297 4298 <DT><b><a name="lmtp_sasl_tls_verified_security_options">lmtp_sasl_tls_verified_security_options</a> 4299 (default: $<a href="postconf.5.html#lmtp_sasl_tls_security_options">lmtp_sasl_tls_security_options</a>)</b></DT><DD> 4300 4301 <p> The LMTP-specific version of the 4302 <a href="postconf.5.html#smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a> configuration parameter. 4303 See there for details. </p> 4304 4305 <p> This feature is available in Postfix 2.3 and later. </p> 4306 4307 4308 </DD> 4309 4310 <DT><b><a name="lmtp_sasl_type">lmtp_sasl_type</a> 4311 (default: cyrus)</b></DT><DD> 4312 4313 <p> The SASL plug-in type that the Postfix LMTP client should use 4314 for authentication. The available types are listed with the 4315 "<b>postconf -A</b>" command. </p> 4316 4317 <p> This feature is available in Postfix 2.3 and later. </p> 4318 4319 4320 </DD> 4321 4322 <DT><b><a name="lmtp_send_xforward_command">lmtp_send_xforward_command</a> 4323 (default: no)</b></DT><DD> 4324 4325 <p> 4326 Send an XFORWARD command to the LMTP server when the LMTP LHLO 4327 server response announces XFORWARD support. This allows an <a href="lmtp.8.html">lmtp(8)</a> 4328 delivery agent, used for content filter message injection, to 4329 forward the name, address, protocol and HELO name of the original 4330 client to the content filter and downstream queuing LMTP server. 4331 Before you change the value to yes, it is best to make sure that 4332 your content filter supports this command. 4333 </p> 4334 4335 <p> 4336 This feature is available in Postfix 2.1 and later. 4337 </p> 4338 4339 4340 </DD> 4341 4342 <DT><b><a name="lmtp_sender_dependent_authentication">lmtp_sender_dependent_authentication</a> 4343 (default: no)</b></DT><DD> 4344 4345 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sender_dependent_authentication">smtp_sender_dependent_authentication</a> 4346 configuration parameter. See there for details. </p> 4347 4348 <p> This feature is available in Postfix 2.3 and later. </p> 4349 4350 4351 </DD> 4352 4353 <DT><b><a name="lmtp_skip_5xx_greeting">lmtp_skip_5xx_greeting</a> 4354 (default: yes)</b></DT><DD> 4355 4356 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_skip_5xx_greeting">smtp_skip_5xx_greeting</a> 4357 configuration parameter. See there for details. </p> 4358 4359 <p> This feature is available in Postfix 2.3 and later. </p> 4360 4361 4362 </DD> 4363 4364 <DT><b><a name="lmtp_skip_quit_response">lmtp_skip_quit_response</a> 4365 (default: no)</b></DT><DD> 4366 4367 <p> 4368 Wait for the response to the LMTP QUIT command. 4369 </p> 4370 4371 4372 </DD> 4373 4374 <DT><b><a name="lmtp_starttls_timeout">lmtp_starttls_timeout</a> 4375 (default: 300s)</b></DT><DD> 4376 4377 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_starttls_timeout">smtp_starttls_timeout</a> configuration 4378 parameter. See there for details. </p> 4379 4380 <p> This feature is available in Postfix 2.3 and later. </p> 4381 4382 4383 </DD> 4384 4385 <DT><b><a name="lmtp_tcp_port">lmtp_tcp_port</a> 4386 (default: 24)</b></DT><DD> 4387 4388 <p> 4389 The default TCP port that the Postfix LMTP client connects to. 4390 </p> 4391 4392 4393 </DD> 4394 4395 <DT><b><a name="lmtp_tls_CAfile">lmtp_tls_CAfile</a> 4396 (default: empty)</b></DT><DD> 4397 4398 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a> 4399 configuration parameter. See there for details. </p> 4400 4401 <p> This feature is available in Postfix 2.3 and later. </p> 4402 4403 4404 </DD> 4405 4406 <DT><b><a name="lmtp_tls_CApath">lmtp_tls_CApath</a> 4407 (default: empty)</b></DT><DD> 4408 4409 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a> 4410 configuration parameter. See there for details. </p> 4411 4412 <p> This feature is available in Postfix 2.3 and later. </p> 4413 4414 4415 </DD> 4416 4417 <DT><b><a name="lmtp_tls_block_early_mail_reply">lmtp_tls_block_early_mail_reply</a> 4418 (default: empty)</b></DT><DD> 4419 4420 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_block_early_mail_reply">smtp_tls_block_early_mail_reply</a> 4421 configuration parameter. See there for details. </p> 4422 4423 <p> This feature is available in Postfix 2.7 and later. </p> 4424 4425 4426 </DD> 4427 4428 <DT><b><a name="lmtp_tls_cert_file">lmtp_tls_cert_file</a> 4429 (default: empty)</b></DT><DD> 4430 4431 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> 4432 configuration parameter. See there for details. </p> 4433 4434 <p> This feature is available in Postfix 2.3 and later. </p> 4435 4436 4437 </DD> 4438 4439 <DT><b><a name="lmtp_tls_ciphers">lmtp_tls_ciphers</a> 4440 (default: export)</b></DT><DD> 4441 4442 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> configuration 4443 parameter. See there for details. </p> 4444 4445 <p> This feature is available in Postfix 2.6 and later. </p> 4446 4447 4448 </DD> 4449 4450 <DT><b><a name="lmtp_tls_dcert_file">lmtp_tls_dcert_file</a> 4451 (default: empty)</b></DT><DD> 4452 4453 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> 4454 configuration parameter. See there for details. </p> 4455 4456 <p> This feature is available in Postfix 2.3 and later. </p> 4457 4458 4459 </DD> 4460 4461 <DT><b><a name="lmtp_tls_dkey_file">lmtp_tls_dkey_file</a> 4462 (default: $<a href="postconf.5.html#lmtp_tls_dcert_file">lmtp_tls_dcert_file</a>)</b></DT><DD> 4463 4464 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_dkey_file">smtp_tls_dkey_file</a> 4465 configuration parameter. See there for details. </p> 4466 4467 <p> This feature is available in Postfix 2.3 and later. </p> 4468 4469 4470 </DD> 4471 4472 <DT><b><a name="lmtp_tls_eccert_file">lmtp_tls_eccert_file</a> 4473 (default: empty)</b></DT><DD> 4474 4475 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a> configuration 4476 parameter. See there for details. </p> 4477 4478 <p> This feature is available in Postfix 2.6 and later, when Postfix is 4479 compiled and linked with OpenSSL 1.0.0 or later. </p> 4480 4481 4482 </DD> 4483 4484 <DT><b><a name="lmtp_tls_eckey_file">lmtp_tls_eckey_file</a> 4485 (default: empty)</b></DT><DD> 4486 4487 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_eckey_file">smtp_tls_eckey_file</a> configuration 4488 parameter. See there for details. </p> 4489 4490 <p> This feature is available in Postfix 2.6 and later, when Postfix is 4491 compiled and linked with OpenSSL 1.0.0 or later. </p> 4492 4493 4494 </DD> 4495 4496 <DT><b><a name="lmtp_tls_enforce_peername">lmtp_tls_enforce_peername</a> 4497 (default: yes)</b></DT><DD> 4498 4499 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> 4500 configuration parameter. See there for details. </p> 4501 4502 <p> This feature is available in Postfix 2.3 and later. </p> 4503 4504 4505 </DD> 4506 4507 <DT><b><a name="lmtp_tls_exclude_ciphers">lmtp_tls_exclude_ciphers</a> 4508 (default: empty)</b></DT><DD> 4509 4510 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> 4511 configuration parameter. See there for details. </p> 4512 4513 <p> This feature is available in Postfix 2.3 and later. </p> 4514 4515 4516 </DD> 4517 4518 <DT><b><a name="lmtp_tls_fingerprint_cert_match">lmtp_tls_fingerprint_cert_match</a> 4519 (default: empty)</b></DT><DD> 4520 4521 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> 4522 configuration parameter. See there for details. </p> 4523 4524 <p> This feature is available in Postfix 2.5 and later. </p> 4525 4526 4527 </DD> 4528 4529 <DT><b><a name="lmtp_tls_fingerprint_digest">lmtp_tls_fingerprint_digest</a> 4530 (default: md5)</b></DT><DD> 4531 4532 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> 4533 configuration parameter. See there for details. </p> 4534 4535 <p> This feature is available in Postfix 2.5 and later. </p> 4536 4537 4538 </DD> 4539 4540 <DT><b><a name="lmtp_tls_key_file">lmtp_tls_key_file</a> 4541 (default: $<a href="postconf.5.html#lmtp_tls_cert_file">lmtp_tls_cert_file</a>)</b></DT><DD> 4542 4543 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a> 4544 configuration parameter. See there for details. </p> 4545 4546 <p> This feature is available in Postfix 2.3 and later. </p> 4547 4548 4549 </DD> 4550 4551 <DT><b><a name="lmtp_tls_loglevel">lmtp_tls_loglevel</a> 4552 (default: 0)</b></DT><DD> 4553 4554 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_loglevel">smtp_tls_loglevel</a> 4555 configuration parameter. See there for details. </p> 4556 4557 <p> This feature is available in Postfix 2.3 and later. </p> 4558 4559 4560 </DD> 4561 4562 <DT><b><a name="lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a> 4563 (default: empty)</b></DT><DD> 4564 4565 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> 4566 configuration parameter. See there for details. </p> 4567 4568 <p> This feature is available in Postfix 2.3 and later. </p> 4569 4570 4571 </DD> 4572 4573 <DT><b><a name="lmtp_tls_mandatory_exclude_ciphers">lmtp_tls_mandatory_exclude_ciphers</a> 4574 (default: empty)</b></DT><DD> 4575 4576 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> 4577 configuration parameter. See there for details. </p> 4578 4579 <p> This feature is available in Postfix 2.3 and later. </p> 4580 4581 4582 </DD> 4583 4584 <DT><b><a name="lmtp_tls_mandatory_protocols">lmtp_tls_mandatory_protocols</a> 4585 (default: !SSLv2)</b></DT><DD> 4586 4587 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> 4588 configuration parameter. See there for details. </p> 4589 4590 <p> This feature is available in Postfix 2.3 and later. </p> 4591 4592 4593 </DD> 4594 4595 <DT><b><a name="lmtp_tls_note_starttls_offer">lmtp_tls_note_starttls_offer</a> 4596 (default: no)</b></DT><DD> 4597 4598 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_note_starttls_offer">smtp_tls_note_starttls_offer</a> 4599 configuration parameter. See there for details. </p> 4600 4601 <p> This feature is available in Postfix 2.3 and later. </p> 4602 4603 4604 </DD> 4605 4606 <DT><b><a name="lmtp_tls_per_site">lmtp_tls_per_site</a> 4607 (default: empty)</b></DT><DD> 4608 4609 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> configuration 4610 parameter. See there for details. </p> 4611 4612 <p> This feature is available in Postfix 2.3 and later. </p> 4613 4614 4615 </DD> 4616 4617 <DT><b><a name="lmtp_tls_policy_maps">lmtp_tls_policy_maps</a> 4618 (default: empty)</b></DT><DD> 4619 4620 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> 4621 configuration parameter. See there for details. </p> 4622 4623 <p> This feature is available in Postfix 2.3 and later. </p> 4624 4625 4626 </DD> 4627 4628 <DT><b><a name="lmtp_tls_protocols">lmtp_tls_protocols</a> 4629 (default: empty)</b></DT><DD> 4630 4631 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> configuration 4632 parameter. See there for details. </p> 4633 4634 <p> This feature is available in Postfix 2.6 and later. </p> 4635 4636 4637 </DD> 4638 4639 <DT><b><a name="lmtp_tls_scert_verifydepth">lmtp_tls_scert_verifydepth</a> 4640 (default: 9)</b></DT><DD> 4641 4642 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_scert_verifydepth">smtp_tls_scert_verifydepth</a> 4643 configuration parameter. See there for details. </p> 4644 4645 <p> This feature is available in Postfix 2.3 and later. </p> 4646 4647 4648 </DD> 4649 4650 <DT><b><a name="lmtp_tls_secure_cert_match">lmtp_tls_secure_cert_match</a> 4651 (default: nexthop)</b></DT><DD> 4652 4653 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> 4654 configuration parameter. See there for details. </p> 4655 4656 <p> This feature is available in Postfix 2.3 and later. </p> 4657 4658 4659 </DD> 4660 4661 <DT><b><a name="lmtp_tls_security_level">lmtp_tls_security_level</a> 4662 (default: empty)</b></DT><DD> 4663 4664 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> configuration 4665 parameter. See there for details. </p> 4666 4667 <p> This feature is available in Postfix 2.3 and later. </p> 4668 4669 4670 </DD> 4671 4672 <DT><b><a name="lmtp_tls_session_cache_database">lmtp_tls_session_cache_database</a> 4673 (default: empty)</b></DT><DD> 4674 4675 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> 4676 configuration parameter. See there for details. </p> 4677 4678 <p> This feature is available in Postfix 2.3 and later. </p> 4679 4680 4681 </DD> 4682 4683 <DT><b><a name="lmtp_tls_session_cache_timeout">lmtp_tls_session_cache_timeout</a> 4684 (default: 3600s)</b></DT><DD> 4685 4686 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a> 4687 configuration parameter. See there for details. </p> 4688 4689 <p> This feature is available in Postfix 2.3 and later. </p> 4690 4691 4692 </DD> 4693 4694 <DT><b><a name="lmtp_tls_verify_cert_match">lmtp_tls_verify_cert_match</a> 4695 (default: hostname)</b></DT><DD> 4696 4697 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> 4698 configuration parameter. See there for details. </p> 4699 4700 <p> This feature is available in Postfix 2.3 and later. </p> 4701 4702 4703 </DD> 4704 4705 <DT><b><a name="lmtp_use_tls">lmtp_use_tls</a> 4706 (default: no)</b></DT><DD> 4707 4708 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a> configuration 4709 parameter. See there for details. </p> 4710 4711 <p> This feature is available in Postfix 2.3 and later. </p> 4712 4713 4714 </DD> 4715 4716 <DT><b><a name="lmtp_xforward_timeout">lmtp_xforward_timeout</a> 4717 (default: 300s)</b></DT><DD> 4718 4719 <p> 4720 The LMTP client time limit for sending the XFORWARD command, and 4721 for receiving the server response. 4722 </p> 4723 4724 <p> 4725 In case of problems the client does NOT try the next address on 4726 the mail exchanger list. 4727 </p> 4728 4729 <p> 4730 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 4731 The default time unit is s (seconds). 4732 </p> 4733 4734 <p> 4735 This feature is available in Postfix 2.1 and later. 4736 </p> 4737 4738 4739 </DD> 4740 4741 <DT><b><a name="local_command_shell">local_command_shell</a> 4742 (default: empty)</b></DT><DD> 4743 4744 <p> 4745 Optional shell program for <a href="local.8.html">local(8)</a> delivery to non-Postfix command. 4746 By default, non-Postfix commands are executed directly; commands 4747 are given to given to the default shell (typically, /bin/sh) only 4748 when they contain shell meta characters or shell built-in commands. 4749 </p> 4750 4751 <p> "sendmail's restricted shell" (smrsh) is what most people will 4752 use in order to restrict what programs can be run from e.g. .forward 4753 files (smrsh is part of the Sendmail distribution). </p> 4754 4755 <p> Note: when a shell program is specified, it is invoked even 4756 when the command contains no shell built-in commands or meta 4757 characters. </p> 4758 4759 <p> 4760 Example: 4761 </p> 4762 4763 <pre> 4764 <a href="postconf.5.html#local_command_shell">local_command_shell</a> = /some/where/smrsh -c 4765 <a href="postconf.5.html#local_command_shell">local_command_shell</a> = /bin/bash -c 4766 </pre> 4767 4768 4769 </DD> 4770 4771 <DT><b><a name="local_destination_concurrency_limit">local_destination_concurrency_limit</a> 4772 (default: 2)</b></DT><DD> 4773 4774 <p> The maximal number of parallel deliveries via the local mail 4775 delivery transport to the same recipient (when 4776 "<a href="postconf.5.html#local_destination_recipient_limit">local_destination_recipient_limit</a> = 1") or the maximal number of 4777 parallel deliveries to the same <a href="ADDRESS_CLASS_README.html#local_domain_class">local domain</a> (when 4778 "<a href="postconf.5.html#local_destination_recipient_limit">local_destination_recipient_limit</a> > 1"). This limit is enforced by 4779 the queue manager. The message delivery transport name is the first 4780 field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 4781 4782 <p> A low limit of 2 is recommended, just in case someone has an 4783 expensive shell command in a .forward file or in an alias (e.g., 4784 a mailing list manager). You don't want to run lots of those at 4785 the same time. </p> 4786 4787 4788 </DD> 4789 4790 <DT><b><a name="local_destination_recipient_limit">local_destination_recipient_limit</a> 4791 (default: 1)</b></DT><DD> 4792 4793 <p> The maximal number of recipients per message delivery via the 4794 local mail delivery transport. This limit is enforced by the queue 4795 manager. The message delivery transport name is the first field in 4796 the entry in the <a href="master.5.html">master.cf</a> file. </p> 4797 4798 <p> Setting this parameter to a value > 1 changes the meaning of 4799 <a href="postconf.5.html#local_destination_concurrency_limit">local_destination_concurrency_limit</a> from concurrency per recipient 4800 into concurrency per domain. </p> 4801 4802 4803 </DD> 4804 4805 <DT><b><a name="local_header_rewrite_clients">local_header_rewrite_clients</a> 4806 (default: <a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</a>)</b></DT><DD> 4807 4808 <p> Rewrite message header addresses in mail from these clients and 4809 update incomplete addresses with the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or 4810 $<a href="postconf.5.html#mydomain">mydomain</a>; either don't rewrite message headers from other clients 4811 at all, or rewrite message headers and update incomplete addresses 4812 with the domain specified in the <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> 4813 parameter. </p> 4814 4815 <p> See the <a href="postconf.5.html#append_at_myorigin">append_at_myorigin</a> and <a href="postconf.5.html#append_dot_mydomain">append_dot_mydomain</a> parameters 4816 for details of how domain names are appended to incomplete addresses. 4817 </p> 4818 4819 <p> Specify a list of zero or more of the following: </p> 4820 4821 <dl> 4822 4823 <dt><b><a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</a></b></dt> 4824 4825 <dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the 4826 client IP address matches $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>. This is enabled by 4827 default. </dd> 4828 4829 <dt><b><a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a></b></dt> 4830 4831 <dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the 4832 client IP address matches any network or network address listed in 4833 $<a href="postconf.5.html#mynetworks">mynetworks</a>. This setting will not prevent remote mail header 4834 address rewriting when mail from a remote client is forwarded by 4835 a neighboring system. </dd> 4836 4837 <dt><b><a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a> </b></dt> 4838 4839 <dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the 4840 client is successfully authenticated via the <a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a> (AUTH) 4841 protocol. </dd> 4842 4843 <dt><b><a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> </b></dt> 4844 4845 <dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the 4846 client TLS certificate fingerprint is listed in $<a href="postconf.5.html#relay_clientcerts">relay_clientcerts</a>. 4847 The fingerprint digest algorithm is configurable via the 4848 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to 4849 Postfix version 2.5). </dd> 4850 4851 <dt><b><a href="postconf.5.html#permit_tls_all_clientcerts">permit_tls_all_clientcerts</a> </b></dt> 4852 4853 <dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the 4854 client TLS certificate is successfully verified, regardless of 4855 whether it is listed on the server, and regardless of the certifying 4856 authority. </dd> 4857 4858 <dt><b><a name="check_address_map">check_address_map</a> <i><a href="DATABASE_README.html">type:table</a></i> </b></dt> 4859 4860 <dt><b><i><a href="DATABASE_README.html">type:table</a></i> </b></dt> 4861 4862 <dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the 4863 client IP address matches the specified lookup table. 4864 The lookup result is ignored, and no subnet lookup is done. This 4865 is suitable for, e.g., pop-before-smtp lookup tables. </dd> 4866 4867 </dl> 4868 4869 <p> Examples: </p> 4870 4871 <p> The Postfix < 2.2 backwards compatible setting: always rewrite 4872 message headers, and always append my own domain to incomplete 4873 header addresses. </p> 4874 4875 <blockquote> 4876 <pre> 4877 <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all 4878 </pre> 4879 </blockquote> 4880 4881 <p> The purist (and default) setting: rewrite headers only in mail 4882 from Postfix sendmail and in SMTP mail from this machine. </p> 4883 4884 <blockquote> 4885 <pre> 4886 <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</a> 4887 </pre> 4888 </blockquote> 4889 4890 <p> The intermediate setting: rewrite header addresses and append 4891 $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> information only with mail from Postfix 4892 sendmail, from local clients, or from authorized SMTP clients. </p> 4893 4894 <p> Note: this setting will not prevent remote mail header address 4895 rewriting when mail from a remote client is forwarded by a neighboring 4896 system. </p> 4897 4898 <blockquote> 4899 <pre> 4900 <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, 4901 <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a> <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> 4902 <a href="postconf.5.html#check_address_map">check_address_map</a> hash:/etc/postfix/pop-before-smtp 4903 </pre> 4904 </blockquote> 4905 4906 4907 </DD> 4908 4909 <DT><b><a name="local_recipient_maps">local_recipient_maps</a> 4910 (default: <a href="proxymap.8.html">proxy</a>:unix:passwd.byname $<a href="postconf.5.html#alias_maps">alias_maps</a>)</b></DT><DD> 4911 4912 <p> Lookup tables with all names or addresses of local recipients: 4913 a recipient address is local when its domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, 4914 $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. Specify @domain as a 4915 wild-card for domains that do not have a valid recipient list. 4916 Technically, tables listed with $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> are used as 4917 lists: Postfix needs to know only if a lookup string is found or 4918 not, but it does not use the result from table lookup. </p> 4919 4920 <p> 4921 If this parameter is non-empty (the default), then the Postfix SMTP 4922 server will reject mail for unknown local users. 4923 </p> 4924 4925 <p> 4926 To turn off local recipient checking in the Postfix SMTP server, 4927 specify "<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> =" (i.e. empty). 4928 </p> 4929 4930 <p> 4931 The default setting assumes that you use the default Postfix local 4932 delivery agent for local delivery. You need to update the 4933 <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> setting if: 4934 </p> 4935 4936 <ul> 4937 4938 <li>You redefine the local delivery agent in <a href="master.5.html">master.cf</a>. 4939 4940 <li>You redefine the "<a href="postconf.5.html#local_transport">local_transport</a>" setting in <a href="postconf.5.html">main.cf</a>. 4941 4942 <li>You use the "<a href="postconf.5.html#luser_relay">luser_relay</a>", "<a href="postconf.5.html#mailbox_transport">mailbox_transport</a>", or "<a href="postconf.5.html#fallback_transport">fallback_transport</a>" 4943 feature of the Postfix <a href="local.8.html">local(8)</a> delivery agent. 4944 4945 </ul> 4946 4947 <p> 4948 Details are described in the <a href="LOCAL_RECIPIENT_README.html">LOCAL_RECIPIENT_README</a> file. 4949 </p> 4950 4951 <p> 4952 Beware: if the Postfix SMTP server runs chrooted, you need to access 4953 the passwd file via the <a href="proxymap.8.html">proxymap(8)</a> service, in order to overcome 4954 chroot access restrictions. The alternative, maintaining a copy of 4955 the system password file in the chroot jail is not practical. 4956 </p> 4957 4958 <p> 4959 Examples: 4960 </p> 4961 4962 <pre> 4963 <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> = 4964 </pre> 4965 4966 4967 </DD> 4968 4969 <DT><b><a name="local_transport">local_transport</a> 4970 (default: <a href="local.8.html">local</a>:$<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 4971 4972 <p> The default mail delivery transport and next-hop destination 4973 for final delivery to domains listed with <a href="postconf.5.html#mydestination">mydestination</a>, and for 4974 [ipaddress] destinations that match $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. 4975 This information can be overruled with the <a href="transport.5.html">transport(5)</a> table. </p> 4976 4977 <p> 4978 By default, local mail is delivered to the transport called "local", 4979 which is just the name of a service that is defined the <a href="master.5.html">master.cf</a> file. 4980 </p> 4981 4982 <p> 4983 Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i> 4984 is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>. 4985 The <i>:nexthop</i> destination is optional; its syntax is documented 4986 in the manual page of the corresponding delivery agent. 4987 </p> 4988 4989 <p> 4990 Beware: if you override the default local delivery agent then you 4991 need to review the <a href="LOCAL_RECIPIENT_README.html">LOCAL_RECIPIENT_README</a> document, otherwise the 4992 SMTP server may reject mail for local recipients. 4993 </p> 4994 4995 4996 </DD> 4997 4998 <DT><b><a name="luser_relay">luser_relay</a> 4999 (default: empty)</b></DT><DD> 5000 5001 <p> 5002 Optional catch-all destination for unknown <a href="local.8.html">local(8)</a> recipients. 5003 By default, mail for unknown recipients in domains that match 5004 $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> is returned 5005 as undeliverable. 5006 </p> 5007 5008 <p> 5009 The following $name expansions are done on <a href="postconf.5.html#luser_relay">luser_relay</a>: 5010 </p> 5011 5012 <dl> 5013 5014 <dt><b>$domain</b></dt> 5015 5016 <dd>The recipient domain. </dd> 5017 5018 <dt><b>$extension</b></dt> 5019 5020 <dd>The recipient address extension. </dd> 5021 5022 <dt><b>$home</b></dt> 5023 5024 <dd>The recipient's home directory. </dd> 5025 5026 <dt><b>$local</b></dt> 5027 5028 <dd>The entire recipient address localpart. </dd> 5029 5030 <dt><b>$recipient</b></dt> 5031 5032 <dd>The full recipient address. </dd> 5033 5034 <dt><b>$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b></dt> 5035 5036 <dd>The system-wide recipient address extension delimiter. </dd> 5037 5038 <dt><b>$shell</b></dt> 5039 5040 <dd>The recipient's login shell. </dd> 5041 5042 <dt><b>$user</b></dt> 5043 5044 <dd>The recipient username. </dd> 5045 5046 <dt><b>${name?value}</b></dt> 5047 5048 <dd>Expands to <i>value</i> when <i>$name</i> has a non-empty value. </dd> 5049 5050 <dt><b>${name:value}</b></dt> 5051 5052 <dd>Expands to <i>value</i> when <i>$name</i> has an empty value. </dd> 5053 5054 </dl> 5055 5056 <p> 5057 Instead of $name you can also specify ${name} or $(name). 5058 </p> 5059 5060 <p> 5061 Note: <a href="postconf.5.html#luser_relay">luser_relay</a> works only for the Postfix <a href="local.8.html">local(8)</a> delivery agent. 5062 </p> 5063 5064 <p> 5065 Note: if you use this feature for accounts not in the UNIX password 5066 file, then you must specify "<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> =" (i.e. empty) 5067 in the <a href="postconf.5.html">main.cf</a> file, otherwise the Postfix SMTP server will reject mail 5068 for non-UNIX accounts with "User unknown in local recipient table". 5069 </p> 5070 5071 <p> 5072 Examples: 5073 </p> 5074 5075 <pre> 5076 <a href="postconf.5.html#luser_relay">luser_relay</a> = $user (a] other.host 5077 <a href="postconf.5.html#luser_relay">luser_relay</a> = $local (a] other.host 5078 <a href="postconf.5.html#luser_relay">luser_relay</a> = admin+$local 5079 </pre> 5080 5081 5082 </DD> 5083 5084 <DT><b><a name="mail_name">mail_name</a> 5085 (default: Postfix)</b></DT><DD> 5086 5087 <p> 5088 The mail system name that is displayed in Received: headers, in 5089 the SMTP greeting banner, and in bounced mail. 5090 </p> 5091 5092 5093 </DD> 5094 5095 <DT><b><a name="mail_owner">mail_owner</a> 5096 (default: postfix)</b></DT><DD> 5097 5098 <p> 5099 The UNIX system account that owns the Postfix queue and most Postfix 5100 daemon processes. Specify the name of a user account that does 5101 not share a group with other accounts and that owns no other files 5102 or processes on the system. In particular, don't specify nobody 5103 or daemon. PLEASE USE A DEDICATED USER ID AND GROUP ID. 5104 </p> 5105 5106 <p> 5107 When this parameter value is changed you need to re-run "<b>postfix 5108 set-permissions</b>" (with Postfix version 2.0 and earlier: 5109 "<b>/etc/postfix/post-install set-permissions</b>". 5110 </p> 5111 5112 5113 </DD> 5114 5115 <DT><b><a name="mail_release_date">mail_release_date</a> 5116 (default: see "postconf -d" output)</b></DT><DD> 5117 5118 <p> 5119 The Postfix release date, in "YYYYMMDD" format. 5120 </p> 5121 5122 5123 </DD> 5124 5125 <DT><b><a name="mail_spool_directory">mail_spool_directory</a> 5126 (default: see "postconf -d" output)</b></DT><DD> 5127 5128 <p> 5129 The directory where <a href="local.8.html">local(8)</a> UNIX-style mailboxes are kept. The 5130 default setting depends on the system type. Specify a name ending 5131 in / for maildir-style delivery. 5132 </p> 5133 5134 <p> 5135 Note: maildir delivery is done with the privileges of the recipient. 5136 If you use the <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a> setting for maildir style 5137 delivery, then you must create the top-level maildir directory in 5138 advance. Postfix will not create it. 5139 </p> 5140 5141 <p> 5142 Examples: 5143 </p> 5144 5145 <pre> 5146 <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a> = /var/mail 5147 <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a> = /var/spool/mail 5148 </pre> 5149 5150 5151 </DD> 5152 5153 <DT><b><a name="mail_version">mail_version</a> 5154 (default: see "postconf -d" output)</b></DT><DD> 5155 5156 <p> 5157 The version of the mail system. Stable releases are named 5158 <i>major</i>.<i>minor</i>.<i>patchlevel</i>. Experimental releases 5159 also include the release date. The version string can be used in, 5160 for example, the SMTP greeting banner. 5161 </p> 5162 5163 5164 </DD> 5165 5166 <DT><b><a name="mailbox_command">mailbox_command</a> 5167 (default: empty)</b></DT><DD> 5168 5169 <p> 5170 Optional external command that the <a href="local.8.html">local(8)</a> delivery agent should 5171 use for mailbox delivery. The command is run with the user ID and 5172 the primary group ID privileges of the recipient. Exception: 5173 command delivery for root executes with $<a href="postconf.5.html#default_privs">default_privs</a> privileges. 5174 This is not a problem, because 1) mail for root should always be 5175 aliased to a real user and 2) don't log in as root, use "su" instead. 5176 </p> 5177 5178 <p> 5179 The following environment variables are exported to the command: 5180 </p> 5181 5182 <dl> 5183 5184 <dt><b>CLIENT_ADDRESS</b></dt> 5185 5186 <dd>Remote client network address. Available in Postfix version 2.2 and 5187 later. </dd> 5188 5189 <dt><b>CLIENT_HELO</b></dt> 5190 5191 <dd>Remote client EHLO command parameter. Available in Postfix version 2.2 5192 and later.</dd> 5193 5194 <dt><b>CLIENT_HOSTNAME</b></dt> 5195 5196 <dd>Remote client hostname. Available in Postfix version 2.2 and later. 5197 </dd> 5198 5199 <dt><b>CLIENT_PROTOCOL</b></dt> 5200 5201 <dd>Remote client protocol. Available in Postfix version 2.2 and later. 5202 </dd> 5203 5204 <dt><b>DOMAIN</b></dt> 5205 5206 <dd>The domain part of the recipient address. </dd> 5207 5208 <dt><b>EXTENSION</b></dt> 5209 5210 <dd>The optional address extension. </dd> 5211 5212 <dt><b>HOME</b></dt> 5213 5214 <dd>The recipient home directory. </dd> 5215 5216 <dt><b>LOCAL</b></dt> 5217 5218 <dd>The recipient address localpart. </dd> 5219 5220 <dt><b>LOGNAME</b></dt> 5221 5222 <dd>The recipient's username. </dd> 5223 5224 <dt><b>ORIGINAL_RECIPIENT</b></dt> 5225 5226 <dd>The entire recipient address, before any address rewriting or 5227 aliasing. </dd> 5228 5229 <dt><b>RECIPIENT</b></dt> 5230 5231 <dd>The full recipient address. </dd> 5232 5233 <dt><b>SASL_METHOD</b></dt> 5234 5235 <dd>SASL authentication method specified in the remote client AUTH 5236 command. Available in Postfix version 2.2 and later. </dd> 5237 5238 <dt><b>SASL_SENDER</b></dt> 5239 5240 <dd>SASL sender address specified in the remote client MAIL FROM 5241 command. Available in Postfix version 2.2 and later. </dd> 5242 5243 <dt><b>SASL_USER</b></dt> 5244 5245 <dd>SASL username specified in the remote client AUTH command. 5246 Available in Postfix version 2.2 and later. </dd> 5247 5248 <dt><b>SENDER</b></dt> 5249 5250 <dd>The full sender address. </dd> 5251 5252 <dt><b>SHELL</b></dt> 5253 5254 <dd>The recipient's login shell. </dd> 5255 5256 <dt><b>USER</b></dt> 5257 5258 <dd>The recipient username. </dd> 5259 5260 </dl> 5261 5262 <p> 5263 Unlike other Postfix configuration parameters, the <a href="postconf.5.html#mailbox_command">mailbox_command</a> 5264 parameter is not subjected to $name substitutions. This is to make 5265 it easier to specify shell syntax (see example below). 5266 </p> 5267 5268 <p> 5269 If you can, avoid shell meta characters because they will force 5270 Postfix to run an expensive shell process. If you're delivering 5271 via Procmail then running a shell won't make a noticeable difference 5272 in the total cost. 5273 </p> 5274 5275 <p> 5276 Note: if you use the <a href="postconf.5.html#mailbox_command">mailbox_command</a> feature to deliver mail 5277 system-wide, you must set up an alias that forwards mail for root 5278 to a real user. 5279 </p> 5280 5281 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 5282 is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>, 5283 <a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>, 5284 <a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p> 5285 5286 <p> 5287 Examples: 5288 </p> 5289 5290 <pre> 5291 <a href="postconf.5.html#mailbox_command">mailbox_command</a> = /some/where/procmail 5292 <a href="postconf.5.html#mailbox_command">mailbox_command</a> = /some/where/procmail -a "$EXTENSION" 5293 <a href="postconf.5.html#mailbox_command">mailbox_command</a> = /some/where/maildrop -d "$USER" 5294 -f "$SENDER" "$EXTENSION" 5295 </pre> 5296 5297 5298 </DD> 5299 5300 <DT><b><a name="mailbox_command_maps">mailbox_command_maps</a> 5301 (default: empty)</b></DT><DD> 5302 5303 <p> 5304 Optional lookup tables with per-recipient external commands to use 5305 for <a href="local.8.html">local(8)</a> mailbox delivery. Behavior is as with <a href="postconf.5.html#mailbox_command">mailbox_command</a>. 5306 </p> 5307 5308 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 5309 is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>, 5310 <a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>, 5311 <a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p> 5312 5313 5314 </DD> 5315 5316 <DT><b><a name="mailbox_delivery_lock">mailbox_delivery_lock</a> 5317 (default: see "postconf -d" output)</b></DT><DD> 5318 5319 <p> 5320 How to lock a UNIX-style <a href="local.8.html">local(8)</a> mailbox before attempting delivery. 5321 For a list of available file locking methods, use the "<b>postconf 5322 -l</b>" command. 5323 </p> 5324 5325 <p> 5326 This setting is ignored with <b>maildir</b> style delivery, 5327 because such deliveries are safe without explicit locks. 5328 </p> 5329 5330 <p> 5331 Note: The <b>dotlock</b> method requires that the recipient UID or 5332 GID has write access to the parent directory of the mailbox file. 5333 </p> 5334 5335 <p> 5336 Note: the default setting of this parameter is system dependent. 5337 </p> 5338 5339 5340 </DD> 5341 5342 <DT><b><a name="mailbox_size_limit">mailbox_size_limit</a> 5343 (default: 51200000)</b></DT><DD> 5344 5345 <p> The maximal size of any <a href="local.8.html">local(8)</a> individual mailbox or maildir 5346 file, or zero (no limit). In fact, this limits the size of any 5347 file that is written to upon local delivery, including files written 5348 by external commands that are executed by the <a href="local.8.html">local(8)</a> delivery 5349 agent. </p> 5350 5351 <p> 5352 This limit must not be smaller than the message size limit. 5353 </p> 5354 5355 5356 </DD> 5357 5358 <DT><b><a name="mailbox_transport">mailbox_transport</a> 5359 (default: empty)</b></DT><DD> 5360 5361 <p> 5362 Optional message delivery transport that the <a href="local.8.html">local(8)</a> delivery 5363 agent should use for mailbox delivery to all local recipients, 5364 whether or not they are found in the UNIX passwd database. 5365 </p> 5366 5367 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 5368 is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>, 5369 <a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>, 5370 <a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p> 5371 5372 5373 </DD> 5374 5375 <DT><b><a name="mailbox_transport_maps">mailbox_transport_maps</a> 5376 (default: empty)</b></DT><DD> 5377 5378 <p> Optional lookup tables with per-recipient message delivery 5379 transports to use for <a href="local.8.html">local(8)</a> mailbox delivery, whether or not the 5380 recipients are found in the UNIX passwd database. </p> 5381 5382 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 5383 is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>, 5384 <a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>, 5385 <a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p> 5386 5387 <p> For safety reasons, this feature does not allow $number 5388 substitutions in regular expression maps. </p> 5389 5390 <p> This feature is available in Postfix 2.3 and later. </p> 5391 5392 5393 </DD> 5394 5395 <DT><b><a name="mailq_path">mailq_path</a> 5396 (default: see "postconf -d" output)</b></DT><DD> 5397 5398 <p> 5399 Sendmail compatibility feature that specifies where the Postfix 5400 <a href="mailq.1.html">mailq(1)</a> command is installed. This command can be used to 5401 list the Postfix mail queue. 5402 </p> 5403 5404 5405 </DD> 5406 5407 <DT><b><a name="manpage_directory">manpage_directory</a> 5408 (default: see "postconf -d" output)</b></DT><DD> 5409 5410 <p> 5411 Where the Postfix manual pages are installed. 5412 </p> 5413 5414 5415 </DD> 5416 5417 <DT><b><a name="maps_rbl_domains">maps_rbl_domains</a> 5418 (default: empty)</b></DT><DD> 5419 5420 <p> 5421 Obsolete feature: use the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> feature instead. 5422 </p> 5423 5424 5425 </DD> 5426 5427 <DT><b><a name="maps_rbl_reject_code">maps_rbl_reject_code</a> 5428 (default: 554)</b></DT><DD> 5429 5430 <p> 5431 The numerical Postfix SMTP server response code when a remote SMTP 5432 client request is blocked by the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a>, <a href="postconf.5.html#reject_rhsbl_client">reject_rhsbl_client</a>, 5433 <a href="postconf.5.html#reject_rhsbl_reverse_client">reject_rhsbl_reverse_client</a>, <a href="postconf.5.html#reject_rhsbl_sender">reject_rhsbl_sender</a> or 5434 <a href="postconf.5.html#reject_rhsbl_recipient">reject_rhsbl_recipient</a> restriction. 5435 </p> 5436 5437 <p> 5438 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 5439 </p> 5440 5441 5442 </DD> 5443 5444 <DT><b><a name="masquerade_classes">masquerade_classes</a> 5445 (default: envelope_sender, header_sender, header_recipient)</b></DT><DD> 5446 5447 <p> 5448 What addresses are subject to address masquerading. 5449 </p> 5450 5451 <p> 5452 By default, address masquerading is limited to envelope sender 5453 addresses, and to header sender and header recipient addresses. 5454 This allows you to use address masquerading on a mail gateway while 5455 still being able to forward mail to users on individual machines. 5456 </p> 5457 5458 <p> 5459 Specify zero or more of: envelope_sender, envelope_recipient, 5460 header_sender, header_recipient 5461 </p> 5462 5463 5464 </DD> 5465 5466 <DT><b><a name="masquerade_domains">masquerade_domains</a> 5467 (default: empty)</b></DT><DD> 5468 5469 <p> 5470 Optional list of domains whose subdomain structure will be stripped 5471 off in email addresses. 5472 </p> 5473 5474 <p> 5475 The list is processed left to right, and processing stops at the 5476 first match. Thus, 5477 </p> 5478 5479 <blockquote> 5480 <pre> 5481 <a href="postconf.5.html#masquerade_domains">masquerade_domains</a> = foo.example.com example.com 5482 </pre> 5483 </blockquote> 5484 5485 <p> 5486 strips "user (a] any.thing.foo.example.com" to "user (a] foo.example.com", 5487 but strips "user (a] any.thing.else.example.com" to "user (a] example.com". 5488 </p> 5489 5490 <p> 5491 A domain name prefixed with ! means do not masquerade this domain 5492 or its subdomains. Thus, 5493 </p> 5494 5495 <blockquote> 5496 <pre> 5497 <a href="postconf.5.html#masquerade_domains">masquerade_domains</a> = !foo.example.com example.com 5498 </pre> 5499 </blockquote> 5500 5501 <p> 5502 does not change "user (a] any.thing.foo.example.com" or "user (a] foo.example.com", 5503 but strips "user (a] any.thing.else.example.com" to "user (a] example.com". 5504 </p> 5505 5506 <p> Note: with Postfix version 2.2, message header address masquerading 5507 happens only when message header address rewriting is enabled: </p> 5508 5509 <ul> 5510 5511 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 5512 5513 <li> The message is received from a network client that matches 5514 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 5515 5516 <li> The message is received from the network, and the 5517 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 5518 5519 </ul> 5520 5521 <p> To get the behavior before Postfix version 2.2, specify 5522 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 5523 5524 <p> 5525 Example: 5526 </p> 5527 5528 <pre> 5529 <a href="postconf.5.html#masquerade_domains">masquerade_domains</a> = $<a href="postconf.5.html#mydomain">mydomain</a> 5530 </pre> 5531 5532 5533 </DD> 5534 5535 <DT><b><a name="masquerade_exceptions">masquerade_exceptions</a> 5536 (default: empty)</b></DT><DD> 5537 5538 <p> 5539 Optional list of user names that are not subjected to address 5540 masquerading, even when their address matches $<a href="postconf.5.html#masquerade_domains">masquerade_domains</a>. 5541 </p> 5542 5543 <p> 5544 By default, address masquerading makes no exceptions. 5545 </p> 5546 5547 <p> 5548 Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns, 5549 separated by commas and/or whitespace. The list is matched left to 5550 right, and the search stops on the first match. A "/file/name" 5551 pattern is replaced 5552 by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name 5553 matches a lookup key (the lookup result is ignored). Continue long 5554 lines by starting the next line with whitespace. Specify "!pattern" 5555 to exclude a name from the list. The form "!/file/name" is supported 5556 only in Postfix version 2.4 and later. </p> 5557 5558 <p> 5559 Examples: 5560 </p> 5561 5562 <pre> 5563 <a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a> = root, mailer-daemon 5564 <a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a> = root 5565 </pre> 5566 5567 5568 </DD> 5569 5570 <DT><b><a name="master_service_disable">master_service_disable</a> 5571 (default: empty)</b></DT><DD> 5572 5573 <p> Selectively disable <a href="master.8.html">master(8)</a> listener ports by service type 5574 or by service name and type. Specify a list of service types 5575 ("inet", "unix", "fifo", or "pass") or "name.type" tuples, where 5576 "name" is the first field of a <a href="master.5.html">master.cf</a> entry and "type" is a 5577 service type. As with other Postfix matchlists, a search stops at 5578 the first match. Specify "!pattern" to exclude a service from the 5579 list. By default, all <a href="master.8.html">master(8)</a> listener ports are enabled. </p> 5580 5581 <p> Note: this feature does not support "/file/name" or "<a href="DATABASE_README.html">type:table</a>" 5582 patterns, nor does it support wildcards such as "*" or "all". This 5583 is intentional. </p> 5584 5585 <p> Examples: </p> 5586 5587 <pre> 5588 # Turn on all <a href="master.8.html">master(8)</a> listener ports (the default). 5589 <a href="postconf.5.html#master_service_disable">master_service_disable</a> = 5590 # Turn off only the main SMTP listener port. 5591 <a href="postconf.5.html#master_service_disable">master_service_disable</a> = smtp.inet 5592 # Turn off all TCP/IP listener ports. 5593 <a href="postconf.5.html#master_service_disable">master_service_disable</a> = inet 5594 # Turn off all TCP/IP listener ports except "foo". 5595 <a href="postconf.5.html#master_service_disable">master_service_disable</a> = !foo.inet, inet 5596 </pre> 5597 5598 <p> This feature is available in Postfix 2.6 and later. </p> 5599 5600 5601 </DD> 5602 5603 <DT><b><a name="max_idle">max_idle</a> 5604 (default: 100s)</b></DT><DD> 5605 5606 <p> 5607 The maximum amount of time that an idle Postfix daemon process waits 5608 for an incoming connection before terminating voluntarily. This 5609 parameter 5610 is ignored by the Postfix queue manager and by other long-lived 5611 Postfix daemon processes. 5612 </p> 5613 5614 <p> 5615 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 5616 The default time unit is s (seconds). 5617 </p> 5618 5619 5620 </DD> 5621 5622 <DT><b><a name="max_use">max_use</a> 5623 (default: 100)</b></DT><DD> 5624 5625 <p> 5626 The maximal number of incoming connections that a Postfix daemon 5627 process will service before terminating voluntarily. This parameter 5628 is ignored by the Postfix queue 5629 manager and by other long-lived Postfix daemon processes. 5630 </p> 5631 5632 5633 </DD> 5634 5635 <DT><b><a name="maximal_backoff_time">maximal_backoff_time</a> 5636 (default: 4000s)</b></DT><DD> 5637 5638 <p> 5639 The maximal time between attempts to deliver a deferred message. 5640 </p> 5641 5642 <p> This parameter should be set to a value greater than or equal 5643 to $<a href="postconf.5.html#minimal_backoff_time">minimal_backoff_time</a>. See also $<a href="postconf.5.html#queue_run_delay">queue_run_delay</a>. </p> 5644 5645 <p> 5646 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 5647 The default time unit is s (seconds). 5648 </p> 5649 5650 5651 </DD> 5652 5653 <DT><b><a name="maximal_queue_lifetime">maximal_queue_lifetime</a> 5654 (default: 5d)</b></DT><DD> 5655 5656 <p> 5657 The maximal time a message is queued before it is sent back as 5658 undeliverable. 5659 </p> 5660 5661 <p> 5662 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 5663 The default time unit is d (days). 5664 </p> 5665 5666 <p> 5667 Specify 0 when mail delivery should be tried only once. 5668 </p> 5669 5670 5671 </DD> 5672 5673 <DT><b><a name="message_reject_characters">message_reject_characters</a> 5674 (default: empty)</b></DT><DD> 5675 5676 <p> The set of characters that Postfix will reject in message 5677 content. The usual C-like escape sequences are recognized: <tt>\a 5678 \b \f \n \r \t \v \<i>ddd</i></tt> (up to three octal digits) and 5679 <tt>\\</tt>. </p> 5680 5681 <p> Example: </p> 5682 5683 <pre> 5684 <a href="postconf.5.html#message_reject_characters">message_reject_characters</a> = \0 5685 </pre> 5686 5687 <p> This feature is available in Postfix 2.3 and later. </p> 5688 5689 5690 </DD> 5691 5692 <DT><b><a name="message_size_limit">message_size_limit</a> 5693 (default: 10240000)</b></DT><DD> 5694 5695 <p> 5696 The maximal size in bytes of a message, including envelope information. 5697 </p> 5698 5699 <p> Note: be careful when making changes. Excessively small values 5700 will result in the loss of non-delivery notifications, when a bounce 5701 message size exceeds the local or remote MTA's message size limit. 5702 </p> 5703 5704 5705 </DD> 5706 5707 <DT><b><a name="message_strip_characters">message_strip_characters</a> 5708 (default: empty)</b></DT><DD> 5709 5710 <p> The set of characters that Postfix will remove from message 5711 content. The usual C-like escape sequences are recognized: <tt>\a 5712 \b \f \n \r \t \v \<i>ddd</i></tt> (up to three octal digits) and 5713 <tt>\\</tt>. </p> 5714 5715 <p> Example: </p> 5716 5717 <pre> 5718 <a href="postconf.5.html#message_strip_characters">message_strip_characters</a> = \0 5719 </pre> 5720 5721 <p> This feature is available in Postfix 2.3 and later. </p> 5722 5723 5724 </DD> 5725 5726 <DT><b><a name="milter_command_timeout">milter_command_timeout</a> 5727 (default: 30s)</b></DT><DD> 5728 5729 <p> The time limit for sending an SMTP command to a Milter (mail 5730 filter) application, and for receiving the response. </p> 5731 5732 <p> Specify a non-zero time value (an integral value plus an optional 5733 one-letter suffix that specifies the time unit). </p> 5734 5735 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 5736 (weeks). The default time unit is s (seconds). </p> 5737 5738 <p> This feature is available in Postfix 2.3 and later. </p> 5739 5740 5741 </DD> 5742 5743 <DT><b><a name="milter_connect_macros">milter_connect_macros</a> 5744 (default: see "postconf -d" output)</b></DT><DD> 5745 5746 <p> The macros that are sent to Milter (mail filter) applications 5747 after completion of an SMTP connection. See <a href="MILTER_README.html">MILTER_README</a> 5748 for a list of available macro names and their meanings. </p> 5749 5750 <p> This feature is available in Postfix 2.3 and later. </p> 5751 5752 5753 </DD> 5754 5755 <DT><b><a name="milter_connect_timeout">milter_connect_timeout</a> 5756 (default: 30s)</b></DT><DD> 5757 5758 <p> The time limit for connecting to a Milter (mail filter) 5759 application, and for negotiating protocol options. </p> 5760 5761 <p> Specify a non-zero time value (an integral value plus an optional 5762 one-letter suffix that specifies the time unit). </p> 5763 5764 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 5765 (weeks). The default time unit is s (seconds). </p> 5766 5767 <p> This feature is available in Postfix 2.3 and later. </p> 5768 5769 5770 </DD> 5771 5772 <DT><b><a name="milter_content_timeout">milter_content_timeout</a> 5773 (default: 300s)</b></DT><DD> 5774 5775 <p> The time limit for sending message content to a Milter (mail 5776 filter) application, and for receiving the response. </p> 5777 5778 <p> Specify a non-zero time value (an integral value plus an optional 5779 one-letter suffix that specifies the time unit). </p> 5780 5781 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 5782 (weeks). The default time unit is s (seconds). </p> 5783 5784 <p> This feature is available in Postfix 2.3 and later. </p> 5785 5786 5787 </DD> 5788 5789 <DT><b><a name="milter_data_macros">milter_data_macros</a> 5790 (default: see "postconf -d" output)</b></DT><DD> 5791 5792 <p> The macros that are sent to version 4 or higher Milter (mail 5793 filter) applications after the SMTP DATA command. See <a href="MILTER_README.html">MILTER_README</a> 5794 for a list of available macro names and their meanings. </p> 5795 5796 <p> This feature is available in Postfix 2.3 and later. </p> 5797 5798 5799 </DD> 5800 5801 <DT><b><a name="milter_default_action">milter_default_action</a> 5802 (default: tempfail)</b></DT><DD> 5803 5804 <p> The default action when a Milter (mail filter) application is 5805 unavailable or mis-configured. Specify one of the following: </p> 5806 5807 <dl compact> 5808 5809 <dt>accept</dt> <dd>Proceed as if the mail filter was not present. 5810 </dd> 5811 5812 <dt>reject</dt> <dd>Reject all further commands in this session 5813 with a permanent status code.</dd> 5814 5815 <dt>tempfail</dt> <dd>Reject all further commands in this session 5816 with a temporary status code. </dd> 5817 5818 <dt>quarantine</dt> <dd>Like "accept", but freeze the message in 5819 the "<a href="QSHAPE_README.html#hold_queue">hold" queue</a>. Available with Postfix 2.6 and later. </dd> 5820 5821 </dl> 5822 5823 <p> This feature is available in Postfix 2.3 and later. </p> 5824 5825 5826 </DD> 5827 5828 <DT><b><a name="milter_end_of_data_macros">milter_end_of_data_macros</a> 5829 (default: see "postconf -d" output)</b></DT><DD> 5830 5831 <p> The macros that are sent to Milter (mail filter) applications 5832 after the message end-of-data. See <a href="MILTER_README.html">MILTER_README</a> for a list of 5833 available macro names and their meanings. </p> 5834 5835 <p> This feature is available in Postfix 2.3 and later. </p> 5836 5837 5838 </DD> 5839 5840 <DT><b><a name="milter_end_of_header_macros">milter_end_of_header_macros</a> 5841 (default: see "postconf -d" output)</b></DT><DD> 5842 5843 <p> The macros that are sent to Milter (mail filter) applications 5844 after the end of the message header. See <a href="MILTER_README.html">MILTER_README</a> for a list 5845 of available macro names and their meanings. </p> 5846 5847 <p> This feature is available in Postfix 2.5 and later. </p> 5848 5849 5850 </DD> 5851 5852 <DT><b><a name="milter_header_checks">milter_header_checks</a> 5853 (default: empty)</b></DT><DD> 5854 5855 <p> Optional lookup tables for content inspection of message headers 5856 that are produced by Milter applications. See the <a href="header_checks.5.html">header_checks(5)</a> 5857 manual page available actions. Currently, PREPEND is not implemented. 5858 </p> 5859 5860 <p> The following example sends all mail that is marked as SPAM to 5861 a spam handling machine. Note that matches are case-insensitive 5862 by default. </p> 5863 5864 <pre> 5865 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 5866 <a href="postconf.5.html#milter_header_checks">milter_header_checks</a> = <a href="pcre_table.5.html">pcre</a>:/etc/postfix/<a href="postconf.5.html#milter_header_checks">milter_header_checks</a> 5867 </pre> 5868 5869 <pre> 5870 /etc/postfix/<a href="postconf.5.html#milter_header_checks">milter_header_checks</a>: 5871 /^X-SPAM-FLAG:\s+YES/ FILTER mysmtp:sanitizer.example.com:25 5872 </pre> 5873 5874 <p> The <a href="postconf.5.html#milter_header_checks">milter_header_checks</a> mechanism could also be used for 5875 whitelisting. For example it could be used to skip heavy content 5876 inspection for DKIM-signed mail from known friendly domains. </p> 5877 5878 <p> This feature is available in Postfix 2.7, and as an optional 5879 patch for Postfix 2.6. </p> 5880 5881 5882 </DD> 5883 5884 <DT><b><a name="milter_helo_macros">milter_helo_macros</a> 5885 (default: see "postconf -d" output)</b></DT><DD> 5886 5887 <p> The macros that are sent to Milter (mail filter) applications 5888 after the SMTP HELO or EHLO command. See 5889 <a href="MILTER_README.html">MILTER_README</a> for a list of available macro names and their meanings. 5890 </p> 5891 5892 <p> This feature is available in Postfix 2.3 and later. </p> 5893 5894 5895 </DD> 5896 5897 <DT><b><a name="milter_macro_daemon_name">milter_macro_daemon_name</a> 5898 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 5899 5900 <p> The {daemon_name} macro value for Milter (mail filter) applications. 5901 See <a href="MILTER_README.html">MILTER_README</a> for a list of available macro names and their 5902 meanings. </p> 5903 5904 <p> This feature is available in Postfix 2.3 and later. </p> 5905 5906 5907 </DD> 5908 5909 <DT><b><a name="milter_macro_v">milter_macro_v</a> 5910 (default: $<a href="postconf.5.html#mail_name">mail_name</a> $<a href="postconf.5.html#mail_version">mail_version</a>)</b></DT><DD> 5911 5912 <p> The {v} macro value for Milter (mail filter) applications. 5913 See <a href="MILTER_README.html">MILTER_README</a> for a list of available macro names and their 5914 meanings. </p> 5915 5916 <p> This feature is available in Postfix 2.3 and later. </p> 5917 5918 5919 </DD> 5920 5921 <DT><b><a name="milter_mail_macros">milter_mail_macros</a> 5922 (default: see "postconf -d" output)</b></DT><DD> 5923 5924 <p> The macros that are sent to Milter (mail filter) applications 5925 after the SMTP MAIL FROM command. See <a href="MILTER_README.html">MILTER_README</a> 5926 for a list of available macro names and their meanings. </p> 5927 5928 <p> This feature is available in Postfix 2.3 and later. </p> 5929 5930 5931 </DD> 5932 5933 <DT><b><a name="milter_protocol">milter_protocol</a> 5934 (default: 6)</b></DT><DD> 5935 5936 <p> The mail filter protocol version and optional protocol extensions 5937 for communication with a Milter application; prior to Postfix 2.6 5938 the default protocol is 2. Postfix 5939 sends this version number during the initial protocol handshake. 5940 It should match the version number that is expected by the mail 5941 filter application (or by its Milter library). </p> 5942 5943 <p>Protocol versions: </p> 5944 5945 <dl compact> 5946 5947 <dt>2</dt> <dd>Use Sendmail 8 mail filter protocol version 2 (default 5948 with Sendmail version 8.11 .. 8.13 and Postfix version 2.3 .. 5949 2.5).</dd> 5950 5951 <dt>3</dt> <dd>Use Sendmail 8 mail filter protocol version 3.</dd> 5952 5953 <dt>4</dt> <dd>Use Sendmail 8 mail filter protocol version 4.</dd> 5954 5955 <dt>6</dt> <dd>Use Sendmail 8 mail filter protocol version 6 (default 5956 with Sendmail version 8.14 and Postfix version 2.6).</dd> 5957 5958 </dl> 5959 5960 <p>Protocol extensions: </p> 5961 5962 <dl compact> 5963 5964 <dt>no_header_reply</dt> <dd> Specify this when the Milter application 5965 will not reply for each individual message header.</dd> 5966 5967 </dl> 5968 5969 <p> This feature is available in Postfix 2.3 and later. </p> 5970 5971 5972 </DD> 5973 5974 <DT><b><a name="milter_rcpt_macros">milter_rcpt_macros</a> 5975 (default: see "postconf -d" output)</b></DT><DD> 5976 5977 <p> The macros that are sent to Milter (mail filter) applications 5978 after the SMTP RCPT TO command. See <a href="MILTER_README.html">MILTER_README</a> 5979 for a list of available macro names and their meanings. </p> 5980 5981 <p> This feature is available in Postfix 2.3 and later. </p> 5982 5983 5984 </DD> 5985 5986 <DT><b><a name="milter_unknown_command_macros">milter_unknown_command_macros</a> 5987 (default: see "postconf -d" output)</b></DT><DD> 5988 5989 <p> The macros that are sent to version 3 or higher Milter (mail 5990 filter) applications after an unknown SMTP command. See <a href="MILTER_README.html">MILTER_README</a> 5991 for a list of available macro names and their meanings. </p> 5992 5993 <p> This feature is available in Postfix 2.3 and later. </p> 5994 5995 5996 </DD> 5997 5998 <DT><b><a name="mime_boundary_length_limit">mime_boundary_length_limit</a> 5999 (default: 2048)</b></DT><DD> 6000 6001 <p> 6002 The maximal length of MIME multipart boundary strings. The MIME 6003 processor is unable to distinguish between boundary strings that 6004 do not differ in the first $<a href="postconf.5.html#mime_boundary_length_limit">mime_boundary_length_limit</a> characters. 6005 </p> 6006 6007 <p> 6008 This feature is available in Postfix 2.0 and later. 6009 </p> 6010 6011 6012 </DD> 6013 6014 <DT><b><a name="mime_header_checks">mime_header_checks</a> 6015 (default: $<a href="postconf.5.html#header_checks">header_checks</a>)</b></DT><DD> 6016 6017 <p> 6018 Optional lookup tables for content inspection of MIME related 6019 message headers, as described in the <a href="header_checks.5.html">header_checks(5)</a> manual page. 6020 </p> 6021 6022 <p> 6023 This feature is available in Postfix 2.0 and later. 6024 </p> 6025 6026 6027 </DD> 6028 6029 <DT><b><a name="mime_nesting_limit">mime_nesting_limit</a> 6030 (default: 100)</b></DT><DD> 6031 6032 <p> 6033 The maximal recursion level that the MIME processor will handle. 6034 Postfix refuses mail that is nested deeper than the specified limit. 6035 </p> 6036 6037 <p> 6038 This feature is available in Postfix 2.0 and later. 6039 </p> 6040 6041 6042 </DD> 6043 6044 <DT><b><a name="minimal_backoff_time">minimal_backoff_time</a> 6045 (default: 300s)</b></DT><DD> 6046 6047 <p> 6048 The minimal time between attempts to deliver a deferred message; 6049 prior to Postfix 2.4 the default value was 1000s. 6050 </p> 6051 6052 <p> 6053 This parameter also limits the time an unreachable destination is 6054 kept in the short-term, in-memory, destination status cache. 6055 </p> 6056 6057 <p> This parameter should be set greater than or equal to 6058 $<a href="postconf.5.html#queue_run_delay">queue_run_delay</a>. See also $<a href="postconf.5.html#maximal_backoff_time">maximal_backoff_time</a>. </p> 6059 6060 <p> 6061 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 6062 The default time unit is s (seconds). 6063 </p> 6064 6065 6066 </DD> 6067 6068 <DT><b><a name="multi_instance_directories">multi_instance_directories</a> 6069 (default: empty)</b></DT><DD> 6070 6071 <p> An optional list of non-default Postfix configuration directories; 6072 these directories belong to additional Postfix instances that share 6073 the Postfix executable files and documentation with the default 6074 Postfix instance, and that are started, stopped, etc., together 6075 with the default Postfix instance. Specify a list of pathnames 6076 separated by comma or whitespace. </p> 6077 6078 <p> When $<a href="postconf.5.html#multi_instance_directories">multi_instance_directories</a> is empty, the <a href="postfix.1.html">postfix(1)</a> command 6079 runs in single-instance mode and operates on a single Postfix 6080 instance only. Otherwise, the <a href="postfix.1.html">postfix(1)</a> command runs in multi-instance 6081 mode and invokes the multi-instance manager specified with the 6082 <a href="postconf.5.html#multi_instance_wrapper">multi_instance_wrapper</a> parameter. The multi-instance manager in 6083 turn executes <a href="postfix.1.html">postfix(1)</a> commands for the default instance and for 6084 all Postfix instances in $<a href="postconf.5.html#multi_instance_directories">multi_instance_directories</a>. </p> 6085 6086 <p> Currently, this parameter setting is ignored except for the 6087 default <a href="postconf.5.html">main.cf</a> file. </p> 6088 6089 <p> This feature is available in Postfix 2.6 and later. </p> 6090 6091 6092 </DD> 6093 6094 <DT><b><a name="multi_instance_enable">multi_instance_enable</a> 6095 (default: no)</b></DT><DD> 6096 6097 <p> Allow this Postfix instance to be started, stopped, etc., by a 6098 multi-instance manager. By default, new instances are created in 6099 a safe state that prevents them from being started inadvertently. 6100 This parameter is reserved for the multi-instance manager. </p> 6101 6102 <p> This feature is available in Postfix 2.6 and later. </p> 6103 6104 6105 </DD> 6106 6107 <DT><b><a name="multi_instance_group">multi_instance_group</a> 6108 (default: empty)</b></DT><DD> 6109 6110 <p> The optional instance group name of this Postfix instance. A 6111 group identifies closely-related Postfix instances that the 6112 multi-instance manager can start, stop, etc., as a unit. This 6113 parameter is reserved for the multi-instance manager. </p> 6114 6115 <p> This feature is available in Postfix 2.6 and later. </p> 6116 6117 6118 </DD> 6119 6120 <DT><b><a name="multi_instance_name">multi_instance_name</a> 6121 (default: empty)</b></DT><DD> 6122 6123 <p> The optional instance name of this Postfix instance. This name 6124 becomes also the default value for the <a href="postconf.5.html#syslog_name">syslog_name</a> parameter. </p> 6125 6126 <p> This feature is available in Postfix 2.6 and later. </p> 6127 6128 6129 </DD> 6130 6131 <DT><b><a name="multi_instance_wrapper">multi_instance_wrapper</a> 6132 (default: empty)</b></DT><DD> 6133 6134 <p> The pathname of a multi-instance manager command that the 6135 <a href="postfix.1.html">postfix(1)</a> command invokes when the <a href="postconf.5.html#multi_instance_directories">multi_instance_directories</a> 6136 parameter value is non-empty. The pathname may be followed by 6137 initial command arguments separated by whitespace; shell 6138 metacharacters such as quotes are not supported in this context. 6139 </p> 6140 6141 <p> The <a href="postfix.1.html">postfix(1)</a> command invokes the manager command with the 6142 <a href="postfix.1.html">postfix(1)</a> non-option command arguments on the manager command line, 6143 and with all installation configuration parameters exported into 6144 the manager command process environment. The manager command in 6145 turn invokes the <a href="postfix.1.html">postfix(1)</a> command for individual Postfix instances 6146 as "postfix -c <i><a href="postconf.5.html#config_directory">config_directory</a></i> <i>command</i>". </p> 6147 6148 <p> This feature is available in Postfix 2.6 and later. </p> 6149 6150 6151 </DD> 6152 6153 <DT><b><a name="multi_recipient_bounce_reject_code">multi_recipient_bounce_reject_code</a> 6154 (default: 550)</b></DT><DD> 6155 6156 <p> 6157 The numerical Postfix SMTP server response code when a remote SMTP 6158 client request is blocked by the <a href="postconf.5.html#reject_multi_recipient_bounce">reject_multi_recipient_bounce</a> 6159 restriction. 6160 </p> 6161 6162 <p> 6163 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 6164 </p> 6165 6166 <p> 6167 This feature is available in Postfix 2.1 and later. 6168 </p> 6169 6170 6171 </DD> 6172 6173 <DT><b><a name="mydestination">mydestination</a> 6174 (default: $<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a>, localhost)</b></DT><DD> 6175 6176 <p> The list of domains that are delivered via the $<a href="postconf.5.html#local_transport">local_transport</a> 6177 mail delivery transport. By default this is the Postfix <a href="local.8.html">local(8)</a> 6178 delivery agent which looks up all recipients in /etc/passwd and 6179 /etc/aliases. The SMTP server validates recipient addresses with 6180 $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> and rejects non-existent recipients. See also 6181 the <a href="ADDRESS_CLASS_README.html#local_domain_class">local domain</a> class in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file. 6182 </p> 6183 6184 <p> 6185 The default <a href="postconf.5.html#mydestination">mydestination</a> value specifies names for the local 6186 machine only. On a mail domain gateway, you should also include 6187 $<a href="postconf.5.html#mydomain">mydomain</a>. 6188 </p> 6189 6190 <p> 6191 The $<a href="postconf.5.html#local_transport">local_transport</a> delivery method is also selected for mail 6192 addressed to user@[the.net.work.address] of the mail system (the 6193 IP addresses specified with the <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> and <a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> 6194 parameters). 6195 </p> 6196 6197 <p> 6198 Warnings: 6199 </p> 6200 6201 <ul> 6202 6203 <li><p>Do not specify the names of virtual domains - those domains 6204 are specified elsewhere. See <a href="VIRTUAL_README.html">VIRTUAL_README</a> for more information. </p> 6205 6206 <li><p>Do not specify the names of domains that this machine is 6207 backup MX host for. See <a href="STANDARD_CONFIGURATION_README.html">STANDARD_CONFIGURATION_README</a> for how to 6208 set up backup MX hosts. </p> 6209 6210 <li><p>By default, the Postfix SMTP server rejects mail for recipients 6211 not listed with the <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> parameter. See the 6212 <a href="postconf.5.html">postconf(5)</a> manual for a description of the <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> 6213 and <a href="postconf.5.html#unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> parameters. </p> 6214 6215 </ul> 6216 6217 <p> 6218 Specify a list of host or domain names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" 6219 patterns, separated by commas and/or whitespace. A "/file/name" 6220 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 6221 is matched when a name matches a lookup key (the lookup result is 6222 ignored). Continue long lines by starting the next line with 6223 whitespace. </p> 6224 6225 <p> 6226 Examples: 6227 </p> 6228 6229 <pre> 6230 <a href="postconf.5.html#mydestination">mydestination</a> = $<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a> $<a href="postconf.5.html#mydomain">mydomain</a> 6231 <a href="postconf.5.html#mydestination">mydestination</a> = $<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a> www.$<a href="postconf.5.html#mydomain">mydomain</a>, ftp.$<a href="postconf.5.html#mydomain">mydomain</a> 6232 </pre> 6233 6234 6235 </DD> 6236 6237 <DT><b><a name="mydomain">mydomain</a> 6238 (default: see "postconf -d" output)</b></DT><DD> 6239 6240 <p> 6241 The internet domain name of this mail system. The default is to 6242 use $<a href="postconf.5.html#myhostname">myhostname</a> minus the first component, or "localdomain" (Postfix 6243 2.3 and later). $<a href="postconf.5.html#mydomain">mydomain</a> is used as 6244 a default value for many other configuration parameters. 6245 </p> 6246 6247 <p> 6248 Example: 6249 </p> 6250 6251 <pre> 6252 <a href="postconf.5.html#mydomain">mydomain</a> = domain.tld 6253 </pre> 6254 6255 6256 </DD> 6257 6258 <DT><b><a name="myhostname">myhostname</a> 6259 (default: see "postconf -d" output)</b></DT><DD> 6260 6261 <p> 6262 The internet hostname of this mail system. The default is to use 6263 the fully-qualified domain name (FQDN) from gethostname(), or to 6264 use the non-FQDN result from gethostname() and append ".$<a href="postconf.5.html#mydomain">mydomain</a>". 6265 $<a href="postconf.5.html#myhostname">myhostname</a> is used as a default value for many other configuration 6266 parameters. </p> 6267 6268 <p> 6269 Example: 6270 </p> 6271 6272 <pre> 6273 <a href="postconf.5.html#myhostname">myhostname</a> = host.example.com 6274 </pre> 6275 6276 6277 </DD> 6278 6279 <DT><b><a name="mynetworks">mynetworks</a> 6280 (default: see "postconf -d" output)</b></DT><DD> 6281 6282 <p> 6283 The list of "trusted" SMTP clients that have more privileges than 6284 "strangers". 6285 </p> 6286 6287 <p> 6288 In particular, "trusted" SMTP clients are allowed to relay mail 6289 through Postfix. See the <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> parameter 6290 description in the <a href="postconf.5.html">postconf(5)</a> manual. 6291 </p> 6292 6293 <p> 6294 You can specify the list of "trusted" network addresses by hand 6295 or you can let Postfix do it for you (which is the default). 6296 See the description of the <a href="postconf.5.html#mynetworks_style">mynetworks_style</a> parameter for more 6297 information. 6298 </p> 6299 6300 <p> 6301 If you specify the <a href="postconf.5.html#mynetworks">mynetworks</a> list by hand, 6302 Postfix ignores the <a href="postconf.5.html#mynetworks_style">mynetworks_style</a> setting. 6303 </p> 6304 6305 <p> Specify a list of network addresses or network/netmask patterns, 6306 separated by commas and/or whitespace. Continue long lines by 6307 starting the next line with whitespace. </p> 6308 6309 <p> The netmask specifies the number of bits in the network part 6310 of a host address. You can also specify "/file/name" or "<a href="DATABASE_README.html">type:table</a>" 6311 patterns. A "/file/name" pattern is replaced by its contents; a 6312 "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a table entry matches a 6313 lookup string (the lookup result is ignored). </p> 6314 6315 <p> The list is matched left to right, and the search stops on the 6316 first match. Specify "!pattern" to exclude an address or network 6317 block from the list. The form "!/file/name" is supported only 6318 in Postfix version 2.4 and later. </p> 6319 6320 <p> Note: IP version 6 address information must be specified inside 6321 <tt>[]</tt> in the <a href="postconf.5.html#mynetworks">mynetworks</a> value, and in files specified with 6322 "/file/name". IP version 6 addresses contain the ":" character, 6323 and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" pattern. </p> 6324 6325 <p> Examples: </p> 6326 6327 <pre> 6328 <a href="postconf.5.html#mynetworks">mynetworks</a> = 127.0.0.0/8 168.100.189.0/28 6329 <a href="postconf.5.html#mynetworks">mynetworks</a> = !192.168.0.1, 192.168.0.0/28 6330 <a href="postconf.5.html#mynetworks">mynetworks</a> = 127.0.0.0/8 168.100.189.0/28 [::1]/128 [2001:240:587::]/64 6331 <a href="postconf.5.html#mynetworks">mynetworks</a> = $<a href="postconf.5.html#config_directory">config_directory</a>/mynetworks 6332 <a href="postconf.5.html#mynetworks">mynetworks</a> = hash:/etc/postfix/network_table 6333 </pre> 6334 6335 6336 </DD> 6337 6338 <DT><b><a name="mynetworks_style">mynetworks_style</a> 6339 (default: subnet)</b></DT><DD> 6340 6341 <p> 6342 The method to generate the default value for the <a href="postconf.5.html#mynetworks">mynetworks</a> parameter. 6343 This is the list of trusted networks for relay access control etc. 6344 </p> 6345 6346 <ul> 6347 6348 <li><p>Specify "<a href="postconf.5.html#mynetworks_style">mynetworks_style</a> = host" when Postfix should 6349 "trust" only the local machine. </p> 6350 6351 <li><p>Specify "<a href="postconf.5.html#mynetworks_style">mynetworks_style</a> = subnet" when Postfix 6352 should "trust" SMTP clients in the same IP subnetworks as the local 6353 machine. On Linux, this works correctly only with interfaces 6354 specified with the "ifconfig" command. </p> 6355 6356 <li><p>Specify "<a href="postconf.5.html#mynetworks_style">mynetworks_style</a> = class" when Postfix should 6357 "trust" SMTP clients in the same IP class A/B/C networks as the 6358 local machine. Don't do this with a dialup site - it would cause 6359 Postfix to "trust" your entire provider's network. Instead, specify 6360 an explicit <a href="postconf.5.html#mynetworks">mynetworks</a> list by hand, as described with the <a href="postconf.5.html#mynetworks">mynetworks</a> 6361 configuration parameter. </p> 6362 6363 </ul> 6364 6365 6366 </DD> 6367 6368 <DT><b><a name="myorigin">myorigin</a> 6369 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 6370 6371 <p> 6372 The domain name that locally-posted mail appears to come 6373 from, and that locally posted mail is delivered to. The default, 6374 $<a href="postconf.5.html#myhostname">myhostname</a>, is adequate for small sites. If you run a domain with 6375 multiple machines, you should (1) change this to $<a href="postconf.5.html#mydomain">mydomain</a> and (2) 6376 set up a domain-wide alias database that aliases each user to 6377 user (a] that.users.mailhost. 6378 </p> 6379 6380 <p> 6381 Example: 6382 </p> 6383 6384 <pre> 6385 <a href="postconf.5.html#myorigin">myorigin</a> = $<a href="postconf.5.html#mydomain">mydomain</a> 6386 </pre> 6387 6388 6389 </DD> 6390 6391 <DT><b><a name="nested_header_checks">nested_header_checks</a> 6392 (default: $<a href="postconf.5.html#header_checks">header_checks</a>)</b></DT><DD> 6393 6394 <p> 6395 Optional lookup tables for content inspection of non-MIME message 6396 headers in attached messages, as described in the <a href="header_checks.5.html">header_checks(5)</a> 6397 manual page. 6398 </p> 6399 6400 <p> 6401 This feature is available in Postfix 2.0 and later. 6402 </p> 6403 6404 6405 </DD> 6406 6407 <DT><b><a name="newaliases_path">newaliases_path</a> 6408 (default: see "postconf -d" output)</b></DT><DD> 6409 6410 <p> 6411 Sendmail compatibility feature that specifies the location of the 6412 <a href="newaliases.1.html">newaliases(1)</a> command. This command can be used to rebuild the 6413 <a href="local.8.html">local(8)</a> <a href="aliases.5.html">aliases(5)</a> database. 6414 </p> 6415 6416 6417 </DD> 6418 6419 <DT><b><a name="non_fqdn_reject_code">non_fqdn_reject_code</a> 6420 (default: 504)</b></DT><DD> 6421 6422 <p> 6423 The numerical Postfix SMTP server reply code when a client request 6424 is rejected by the <a href="postconf.5.html#reject_non_fqdn_helo_hostname">reject_non_fqdn_helo_hostname</a>, <a href="postconf.5.html#reject_non_fqdn_sender">reject_non_fqdn_sender</a> 6425 or <a href="postconf.5.html#reject_non_fqdn_recipient">reject_non_fqdn_recipient</a> restriction. 6426 </p> 6427 6428 6429 </DD> 6430 6431 <DT><b><a name="non_smtpd_milters">non_smtpd_milters</a> 6432 (default: empty)</b></DT><DD> 6433 6434 <p> A list of Milter (mail filter) applications for new mail that 6435 does not arrive via the Postfix <a href="smtpd.8.html">smtpd(8)</a> server. This includes local 6436 submission via the <a href="sendmail.1.html">sendmail(1)</a> command line, new mail that arrives 6437 via the Postfix <a href="qmqpd.8.html">qmqpd(8)</a> server, and old mail that is re-injected 6438 into the queue with "postsuper -r". See the <a href="MILTER_README.html">MILTER_README</a> document 6439 for details. </p> 6440 6441 <p> This feature is available in Postfix 2.3 and later. </p> 6442 6443 6444 </DD> 6445 6446 <DT><b><a name="notify_classes">notify_classes</a> 6447 (default: resource, software)</b></DT><DD> 6448 6449 <p> 6450 The list of error classes that are reported to the postmaster. The 6451 default is to report only the most serious problems. The paranoid 6452 may wish to turn on the policy (UCE and mail relaying) and protocol 6453 error (broken mail software) reports. 6454 </p> 6455 6456 <p> NOTE: postmaster notifications may contain confidential information 6457 such as SASL passwords or message content. It is the system 6458 administrator's responsibility to treat such information with care. 6459 </p> 6460 6461 <p> 6462 The error classes are: 6463 </p> 6464 6465 <dl> 6466 6467 <dt><b>bounce</b> (also implies <b>2bounce</b>)</dt> 6468 6469 <dd>Send the postmaster copies of the headers of bounced mail, and 6470 send transcripts of SMTP sessions when Postfix rejects mail. The 6471 notification is sent to the address specified with the 6472 <a href="postconf.5.html#bounce_notice_recipient">bounce_notice_recipient</a> configuration parameter (default: postmaster). 6473 </dd> 6474 6475 <dt><b>2bounce</b></dt> 6476 6477 <dd>Send undeliverable bounced mail to the postmaster. The notification 6478 is sent to the address specified with the <a href="postconf.5.html#2bounce_notice_recipient">2bounce_notice_recipient</a> 6479 configuration parameter (default: postmaster). </dd> 6480 6481 <dt><b>delay</b></dt> 6482 6483 <dd>Send the postmaster copies of the headers of delayed mail. The 6484 notification is sent to the address specified with the 6485 <a href="postconf.5.html#delay_notice_recipient">delay_notice_recipient</a> configuration parameter (default: postmaster). 6486 </dd> 6487 6488 <dt><b>policy</b></dt> 6489 6490 <dd>Send the postmaster a transcript of the SMTP session when a 6491 client request was rejected because of (UCE) policy. The notification 6492 is sent to the address specified with the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> 6493 configuration parameter (default: postmaster). </dd> 6494 6495 <dt><b>protocol</b></dt> 6496 6497 <dd>Send the postmaster a transcript of the SMTP session in case 6498 of client or server protocol errors. The notification is sent to 6499 the address specified with the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> configuration 6500 parameter (default: postmaster). </dd> 6501 6502 <dt><b>resource</b></dt> 6503 6504 <dd>Inform the postmaster of mail not delivered due to resource 6505 problems. The notification is sent to the address specified with 6506 the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> configuration parameter (default: 6507 postmaster). </dd> 6508 6509 <dt><b>software</b></dt> 6510 6511 <dd>Inform the postmaster of mail not delivered due to software 6512 problems. The notification is sent to the address specified with 6513 the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> configuration parameter (default: 6514 postmaster). </dd> 6515 6516 </dl> 6517 6518 <p> 6519 Examples: 6520 </p> 6521 6522 <pre> 6523 <a href="postconf.5.html#notify_classes">notify_classes</a> = bounce, delay, policy, protocol, resource, software 6524 <a href="postconf.5.html#notify_classes">notify_classes</a> = 2bounce, resource, software 6525 </pre> 6526 6527 6528 </DD> 6529 6530 <DT><b><a name="owner_request_special">owner_request_special</a> 6531 (default: yes)</b></DT><DD> 6532 6533 <p> 6534 Give special treatment to owner-listname and listname-request 6535 address localparts: don't split such addresses when the 6536 <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> is set to "-". This feature is useful for 6537 mailing lists. 6538 </p> 6539 6540 6541 </DD> 6542 6543 <DT><b><a name="parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> 6544 (default: see "postconf -d" output)</b></DT><DD> 6545 6546 <p> 6547 What Postfix features match subdomains of "domain.tld" automatically, 6548 instead of requiring an explicit ".domain.tld" pattern. This is 6549 planned backwards compatibility: eventually, all Postfix features 6550 are expected to require explicit ".domain.tld" style patterns when 6551 you really want to match subdomains. 6552 </p> 6553 6554 6555 </DD> 6556 6557 <DT><b><a name="permit_mx_backup_networks">permit_mx_backup_networks</a> 6558 (default: empty)</b></DT><DD> 6559 6560 <p> 6561 Restrict the use of the <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> SMTP access feature to 6562 only domains whose primary MX hosts match the listed networks. 6563 The parameter value syntax is the same as with the <a href="postconf.5.html#mynetworks">mynetworks</a> 6564 parameter; note, however, that the default value is empty. </p> 6565 6566 6567 </DD> 6568 6569 <DT><b><a name="pickup_service_name">pickup_service_name</a> 6570 (default: pickup)</b></DT><DD> 6571 6572 <p> 6573 The name of the <a href="pickup.8.html">pickup(8)</a> service. This service picks up local mail 6574 submissions from the Postfix <a href="QSHAPE_README.html#maildrop_queue">maildrop queue</a>. 6575 </p> 6576 6577 <p> 6578 This feature is available in Postfix 2.0 and later. 6579 </p> 6580 6581 6582 </DD> 6583 6584 <DT><b><a name="plaintext_reject_code">plaintext_reject_code</a> 6585 (default: 450)</b></DT><DD> 6586 6587 <p> 6588 The numerical Postfix SMTP server response code when a request 6589 is rejected by the <b><a href="postconf.5.html#reject_plaintext_session">reject_plaintext_session</a></b> restriction. 6590 </p> 6591 6592 <p> This feature is available in Postfix 2.3 and later. </p> 6593 6594 6595 </DD> 6596 6597 <DT><b><a name="postmulti_control_commands">postmulti_control_commands</a> 6598 (default: reload flush)</b></DT><DD> 6599 6600 <p> The <a href="postfix.1.html">postfix(1)</a> commands that the <a href="postmulti.1.html">postmulti(1)</a> instance manager 6601 treats as "control" commands, that operate on running instances. For 6602 these commands, disabled instances are skipped. </p> 6603 6604 <p> This feature is available in Postfix 2.6 and later. </p> 6605 6606 6607 </DD> 6608 6609 <DT><b><a name="postmulti_start_commands">postmulti_start_commands</a> 6610 (default: start)</b></DT><DD> 6611 6612 <p> The <a href="postfix.1.html">postfix(1)</a> commands that the <a href="postmulti.1.html">postmulti(1)</a> instance manager treats 6613 as "start" commands. For these commands, disabled instances are "checked" 6614 rather than "started", and failure to "start" a member instance of an 6615 instance group will abort the start-up of later instances. </p> 6616 6617 <p> This feature is available in Postfix 2.6 and later. </p> 6618 6619 6620 </DD> 6621 6622 <DT><b><a name="postmulti_stop_commands">postmulti_stop_commands</a> 6623 (default: see "postconf -d" output)</b></DT><DD> 6624 6625 <p> The <a href="postfix.1.html">postfix(1)</a> commands that the <a href="postmulti.1.html">postmulti(1)</a> instance manager treats 6626 as "stop" commands. For these commands, disabled instances are skipped, 6627 and enabled instances are processed in reverse order. </p> 6628 6629 <p> This feature is available in Postfix 2.6 and later. </p> 6630 6631 6632 </DD> 6633 6634 <DT><b><a name="postscreen_access_list">postscreen_access_list</a> 6635 (default: <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>)</b></DT><DD> 6636 6637 <p> Permanent white/blacklist for remote SMTP client IP addresses. 6638 <a href="postscreen.8.html">postscreen(8)</a> searches this list immediately after a remote SMTP 6639 client connects. Specify a comma- or whitespace-separated list of 6640 commands (in upper or lower case) or lookup tables. The search stops 6641 upon the first command that fires for the client IP address. </p> 6642 6643 <dl> 6644 6645 <dt> <b> <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a> </b> </dt> <dd> Whitelist the client and 6646 terminate the search if the client IP address matches $<a href="postconf.5.html#mynetworks">mynetworks</a>. 6647 Do not subject the client to any before/after 220 greeting tests. 6648 Pass the connection immediately to a Postfix SMTP server process. 6649 </dd> 6650 6651 <dt> <b> <a href="DATABASE_README.html">type:table</a> </b> </dt> <dd> Query the specified lookup 6652 table. Each table lookup result is an access list, except that 6653 access lists inside a table cannot specify <a href="DATABASE_README.html">type:table</a> entries. <br> 6654 To discourage the use of hash, btree, etc. tables, there is no 6655 support for substring matching like <a href="smtpd.8.html">smtpd(8)</a>. Use CIDR tables 6656 instead. </dd> 6657 6658 <dt> <b> permit </b> </dt> <dd> Whitelist the client and terminate 6659 the search. Do not subject the client to any before/after 220 6660 greeting tests. Pass the connection immediately to a Postfix SMTP 6661 server process. </dd> 6662 6663 <dt> <b> reject </b> </dt> <dd> Blacklist the client and terminate 6664 the search. Subject the client to the action configured with the 6665 <a href="postconf.5.html#postscreen_blacklist_action">postscreen_blacklist_action</a> configuration parameter. </dd> 6666 6667 <dt> <b> dunno </b> </dt> <dd> All <a href="postscreen.8.html">postscreen(8)</a> access lists 6668 implicitly have this command at the end. <br> When <b> dunno </b> 6669 is executed inside a lookup table, return from the lookup table and 6670 evaluate the next command. <br> When <b> dunno </b> is executed 6671 outside a lookup table, terminate the search, and subject the client 6672 to the configured before/after 220 greeting tests. </dd> 6673 6674 </dl> 6675 6676 <p> Example: </p> 6677 6678 <pre> 6679 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 6680 <a href="postconf.5.html#postscreen_access_list">postscreen_access_list</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, 6681 <a href="cidr_table.5.html">cidr</a>:/etc/postfix/postscreen_access.cidr 6682 </pre> 6683 6684 <pre> 6685 /etc/postfix/postscreen_access.<a href="cidr_table.5.html">cidr</a>: 6686 # Rules are evaluated in the order as specified. 6687 # Blacklist 192.168.* except 192.168.0.1. 6688 192.168.0.1 dunno 6689 192.168.0.0/16 reject 6690 </pre> 6691 6692 <p> This feature is available in Postfix 2.8. </p> 6693 6694 6695 </DD> 6696 6697 <DT><b><a name="postscreen_bare_newline_action">postscreen_bare_newline_action</a> 6698 (default: ignore)</b></DT><DD> 6699 6700 <p> The action that <a href="postscreen.8.html">postscreen(8)</a> takes when an SMTP client sends 6701 a bare newline character, that is, a newline not preceded by carriage 6702 return. Specify one of the following: </p> 6703 6704 <dl> 6705 6706 <dt> <b>ignore</b> </dt> 6707 6708 <dd> Ignore the failure of this test. Allow other tests to complete. 6709 Do <i>not</i> repeat this test before some the result from some 6710 other test expires. 6711 This option is useful for testing and collecting statistics 6712 without blocking mail permanently. </dd> 6713 6714 <dt> <b>enforce</b> </dt> 6715 6716 <dd> Allow other tests to complete. Reject attempts to deliver mail 6717 with a 550 SMTP reply, and log the helo/sender/recipient information. 6718 Repeat this test the next time the client connects. </dd> 6719 6720 <dt> <b>drop</b> </dt> 6721 6722 <dd> Drop the connection immediately with a 521 SMTP reply. Repeat 6723 this test the next time the client connects. </dd> 6724 6725 </dl> 6726 6727 <p> This feature is available in Postfix 2.8. </p> 6728 6729 6730 </DD> 6731 6732 <DT><b><a name="postscreen_bare_newline_enable">postscreen_bare_newline_enable</a> 6733 (default: no)</b></DT><DD> 6734 6735 <p> Enable "bare newline" SMTP protocol tests in the <a href="postscreen.8.html">postscreen(8)</a> 6736 server. These tests are expensive: a client must disconnect after 6737 it passes the test, before it can talk to a real Postfix SMTP server. 6738 </p> 6739 6740 <p> This feature is available in Postfix 2.8. </p> 6741 6742 6743 </DD> 6744 6745 <DT><b><a name="postscreen_bare_newline_ttl">postscreen_bare_newline_ttl</a> 6746 (default: 30d)</b></DT><DD> 6747 6748 <p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from 6749 a successful "bare newline" SMTP protocol test. During this 6750 time, the client IP address is excluded from this test. The default 6751 is long because a client must disconnect after it passes the test, 6752 before it can talk to a real Postfix SMTP server. </p> 6753 6754 <p> Specify a non-zero time value (an integral value plus an optional 6755 one-letter suffix that specifies the time unit). Time units: s 6756 (seconds), m (minutes), h (hours), d (days), w (weeks). </p> 6757 6758 <p> This feature is available in Postfix 2.8. </p> 6759 6760 6761 </DD> 6762 6763 <DT><b><a name="postscreen_blacklist_action">postscreen_blacklist_action</a> 6764 (default: ignore)</b></DT><DD> 6765 6766 <p> The action that <a href="postscreen.8.html">postscreen(8)</a> takes when an SMTP client is 6767 permanently blacklisted with the <a href="postconf.5.html#postscreen_access_list">postscreen_access_list</a> parameter. 6768 Specify one of the following: </p> 6769 6770 <dl> 6771 6772 <dt> <b>ignore</b> (default) </dt> 6773 6774 <dd> Ignore this result. Allow other tests to complete. Repeat 6775 this test the next time the client connects. 6776 This option is useful for testing and collecting statistics 6777 without blocking mail. </dd> 6778 6779 <dt> <b>enforce</b> </dt> 6780 6781 <dd> Allow other tests to complete. Reject attempts to deliver mail 6782 with a 550 SMTP reply, and log the helo/sender/recipient information. 6783 Repeat this test the next time the client connects. </dd> 6784 6785 <dt> <b>drop</b> </dt> 6786 6787 <dd> Drop the connection immediately with a 521 SMTP reply. Repeat 6788 this test the next time the client connects. </dd> 6789 6790 </dl> 6791 6792 <p> This feature is available in Postfix 2.8. </p> 6793 6794 6795 </DD> 6796 6797 <DT><b><a name="postscreen_cache_cleanup_interval">postscreen_cache_cleanup_interval</a> 6798 (default: 12h)</b></DT><DD> 6799 6800 <p> The amount of time between <a href="postscreen.8.html">postscreen(8)</a> cache cleanup runs. 6801 Cache cleanup increases the load on the cache database and should 6802 therefore not be run frequently. This feature requires that the 6803 cache database supports the "delete" and "sequence" operators. 6804 Specify a zero interval to disable cache cleanup. </p> 6805 6806 <p> After each cache cleanup run, the <a href="postscreen.8.html">postscreen(8)</a> daemon logs the 6807 number of entries that were retained and dropped. A cleanup run is 6808 logged as "partial" when the daemon terminates early after "<b>postfix 6809 reload</b>", "<b>postfix stop</b>", or no requests for $<a href="postconf.5.html#max_idle">max_idle</a> 6810 seconds. </p> 6811 6812 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 6813 (weeks). </p> 6814 6815 <p> This feature is available in Postfix 2.8. </p> 6816 6817 6818 </DD> 6819 6820 <DT><b><a name="postscreen_cache_map">postscreen_cache_map</a> 6821 (default: btree:$<a href="postconf.5.html#data_directory">data_directory</a>/postscreen_cache)</b></DT><DD> 6822 6823 <p> Persistent storage for the <a href="postscreen.8.html">postscreen(8)</a> server decisions. </p> 6824 6825 <p> This feature is available in Postfix 2.8. </p> 6826 6827 6828 </DD> 6829 6830 <DT><b><a name="postscreen_cache_retention_time">postscreen_cache_retention_time</a> 6831 (default: 7d)</b></DT><DD> 6832 6833 <p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will cache an expired 6834 temporary whitelist entry before it is removed. This prevents clients 6835 from being logged as "NEW" just because their cache entry expired 6836 an hour ago. It also prevents the cache from filling up with clients 6837 that passed some deep protocol test once and never came back. </p> 6838 6839 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 6840 (weeks). </p> 6841 6842 <p> This feature is available in Postfix 2.8. </p> 6843 6844 6845 </DD> 6846 6847 <DT><b><a name="postscreen_client_connection_count_limit">postscreen_client_connection_count_limit</a> 6848 (default: $<a href="postconf.5.html#smtpd_client_connection_count_limit">smtpd_client_connection_count_limit</a>)</b></DT><DD> 6849 6850 <p> How many simultaneous connections any client is allowed to have 6851 with the <a href="postscreen.8.html">postscreen(8)</a> daemon. By default, this limit is the same 6852 as with the Postfix SMTP server. Note that the triage process can 6853 take several seconds, with the time spent in <a href="postconf.5.html#postscreen_greet_wait">postscreen_greet_wait</a> 6854 delay, and with the time spent talking to the <a href="postscreen.8.html">postscreen(8)</a> built-in 6855 dummy SMTP protocol engine. </p> 6856 6857 <p> This feature is available in Postfix 2.8. </p> 6858 6859 6860 </DD> 6861 6862 <DT><b><a name="postscreen_command_count_limit">postscreen_command_count_limit</a> 6863 (default: 20)</b></DT><DD> 6864 6865 <p> The limit on the total number of commands per SMTP session for 6866 <a href="postscreen.8.html">postscreen(8)</a>'s built-in SMTP protocol engine. This SMTP engine 6867 defers or rejects all attempts to deliver mail, therefore there is 6868 no need to enforce separate limits on the number of junk commands 6869 and error commands. </p> 6870 6871 <p> This feature is available in Postfix 2.8. </p> 6872 6873 6874 </DD> 6875 6876 <DT><b><a name="postscreen_command_filter">postscreen_command_filter</a> 6877 (default: $<a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a>)</b></DT><DD> 6878 6879 <p> A mechanism to transform commands from remote SMTP clients. 6880 See <a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a> for further details. </p> 6881 6882 <p> This feature is available in Postfix 2.8 and later. </p> 6883 6884 6885 </DD> 6886 6887 <DT><b><a name="postscreen_command_time_limit">postscreen_command_time_limit</a> 6888 (default: ${stress?10}${stress:300}s)</b></DT><DD> 6889 6890 <p> The time limit to read an entire command line with <a href="postscreen.8.html">postscreen(8)</a>'s 6891 built-in SMTP protocol engine. </p> 6892 6893 <p> This feature is available in Postfix 2.8. </p> 6894 6895 6896 </DD> 6897 6898 <DT><b><a name="postscreen_disable_vrfy_command">postscreen_disable_vrfy_command</a> 6899 (default: $<a href="postconf.5.html#disable_vrfy_command">disable_vrfy_command</a>)</b></DT><DD> 6900 6901 <p> Disable the SMTP VRFY command in the <a href="postscreen.8.html">postscreen(8)</a> daemon. See 6902 <a href="postconf.5.html#disable_vrfy_command">disable_vrfy_command</a> for details. </p> 6903 6904 <p> This feature is available in Postfix 2.8. </p> 6905 6906 6907 </DD> 6908 6909 <DT><b><a name="postscreen_discard_ehlo_keyword_address_maps">postscreen_discard_ehlo_keyword_address_maps</a> 6910 (default: $<a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a>)</b></DT><DD> 6911 6912 <p> Lookup tables, indexed by the remote SMTP client address, with 6913 case insensitive lists of EHLO keywords (pipelining, starttls, auth, 6914 etc.) that the <a href="postscreen.8.html">postscreen(8)</a> server will not send in the EHLO response 6915 to a remote SMTP client. See <a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a> for details. 6916 The table is not searched by hostname for robustness reasons. </p> 6917 6918 <p> This feature is available in Postfix 2.8 and later. </p> 6919 6920 6921 </DD> 6922 6923 <DT><b><a name="postscreen_discard_ehlo_keywords">postscreen_discard_ehlo_keywords</a> 6924 (default: $<a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a>)</b></DT><DD> 6925 6926 <p> A case insensitive list of EHLO keywords (pipelining, starttls, 6927 auth, etc.) that the <a href="postscreen.8.html">postscreen(8)</a> server will not send in the EHLO 6928 response to a remote SMTP client. See <a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a> 6929 for details. </p> 6930 6931 <p> This feature is available in Postfix 2.8 and later. </p> 6932 6933 6934 </DD> 6935 6936 <DT><b><a name="postscreen_dnsbl_action">postscreen_dnsbl_action</a> 6937 (default: ignore)</b></DT><DD> 6938 6939 <p>The action that <a href="postscreen.8.html">postscreen(8)</a> takes when an SMTP client's combined 6940 DNSBL score is equal to or greater than a threshold (as defined 6941 with the <a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> and <a href="postconf.5.html#postscreen_dnsbl_threshold">postscreen_dnsbl_threshold</a> 6942 parameters). Specify one of the following: </p> 6943 6944 <dl> 6945 6946 <dt> <b>ignore</b> (default) </dt> 6947 6948 <dd> Ignore the failure of this test. Allow other tests to complete. 6949 Repeat this test the next time the client connects. 6950 This option is useful for testing and collecting statistics 6951 without blocking mail. </dd> 6952 6953 <dt> <b>enforce</b> </dt> 6954 6955 <dd> Allow other tests to complete. Reject attempts to deliver mail 6956 with a 550 SMTP reply, and log the helo/sender/recipient information. 6957 Repeat this test the next time the client connects. </dd> 6958 6959 <dt> <b>drop</b> </dt> 6960 6961 <dd> Drop the connection immediately with a 521 SMTP reply. Repeat 6962 this test the next time the client connects. </dd> 6963 6964 </dl> 6965 6966 <p> This feature is available in Postfix 2.8. </p> 6967 6968 6969 </DD> 6970 6971 <DT><b><a name="postscreen_dnsbl_reply_map">postscreen_dnsbl_reply_map</a> 6972 (default: empty)</b></DT><DD> 6973 6974 <p> A mapping from actual DNSBL domain name which includes a secret 6975 password, to the DNSBL domain name that postscreen will reply with 6976 when it rejects mail. When no mapping is found, the actual DNSBL 6977 domain will be used. </p> 6978 6979 <p> For maximal stability it is best to use a file that is read 6980 into memory such as <a href="pcre_table.5.html">pcre</a>:, <a href="regexp_table.5.html">regexp</a>: or texthash: (texthash: is similar 6981 to hash:, except a) there is no need to run <a href="postmap.1.html">postmap(1)</a> before the 6982 file can be used, and b) texthash: does not detect changes after 6983 the file is read). </p> 6984 6985 <p> Example: </p> 6986 6987 <pre> 6988 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 6989 <a href="postconf.5.html#postscreen_dnsbl_reply_map">postscreen_dnsbl_reply_map</a> = texthash:/etc/postfix/dnsbl_reply 6990 </pre> 6991 6992 <pre> 6993 /etc/postfix/dnsbl_reply: 6994 secret.zen.spamhaus.org zen.spamhaus.org 6995 </pre> 6996 6997 <p> This feature is available in Postfix 2.8. </p> 6998 6999 7000 </DD> 7001 7002 <DT><b><a name="postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> 7003 (default: empty)</b></DT><DD> 7004 7005 <p>Optional list of DNS white/blacklist domains, filters and weight 7006 factors. When the list is non-empty, the <a href="dnsblog.8.html">dnsblog(8)</a> daemon will 7007 query these domains with the IP addresses of remote SMTP clients, 7008 and <a href="postscreen.8.html">postscreen(8)</a> will update an SMTP client's DNSBL score with 7009 each non-error reply. </p> 7010 7011 <p> Caution: when postscreen rejects mail, it replies with the DNSBL 7012 domain name. Use the <a href="postconf.5.html#postscreen_dnsbl_reply_map">postscreen_dnsbl_reply_map</a> feature to hide 7013 "password" information in DNSBL domain names. </p> 7014 7015 <p> When a client's score is equal to or greater than the threshold 7016 specified with <a href="postconf.5.html#postscreen_dnsbl_threshold">postscreen_dnsbl_threshold</a>, <a href="postscreen.8.html">postscreen(8)</a> can drop 7017 the connection with the SMTP client. </p> 7018 7019 <p> Specify a list of domain=filter*weight entries, separated by 7020 comma or whitespace. </p> 7021 7022 <ul> 7023 7024 <li> <p> When no "=filter" is specified, <a href="postscreen.8.html">postscreen(8)</a> will use any 7025 non-error DNSBL reply. Otherwise, <a href="postscreen.8.html">postscreen(8)</a> uses only DNSBL 7026 replies that match the filter. The filter has the form d.d.d.d, 7027 where each d is a number, or a pattern inside [] that contains one 7028 or more ";"-separated numbers or number..number ranges. </p> 7029 7030 <li> <p> When no "*weight" is specified, <a href="postscreen.8.html">postscreen(8)</a> increments 7031 the SMTP client's DNSBL score by 1. Otherwise, the weight must be 7032 an integral number, and <a href="postscreen.8.html">postscreen(8)</a> adds the specified weight to 7033 the SMTP client's DNSBL score. Specify a negative number for 7034 whitelisting. </p> 7035 7036 <li> <p> When one <a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> entry produces multiple 7037 DNSBL responses, <a href="postscreen.8.html">postscreen(8)</a> applies the weight at most once. 7038 </p> 7039 7040 </ul> 7041 7042 <p> Examples: </p> 7043 7044 <p> To use example.com as a high-confidence blocklist, and to 7045 block mail with example.net and example.org only when both agree: 7046 </p> 7047 7048 <pre> 7049 <a href="postconf.5.html#postscreen_dnsbl_threshold">postscreen_dnsbl_threshold</a> = 2 7050 <a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> = example.com*2, example.net, example.org 7051 </pre> 7052 7053 <p> To filter only DNSBL replies containing 127.0.0.4: </p> 7054 7055 <pre> 7056 <a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> = example.com=127.0.0.4 7057 </pre> 7058 7059 <p> This feature is available in Postfix 2.8. </p> 7060 7061 7062 </DD> 7063 7064 <DT><b><a name="postscreen_dnsbl_threshold">postscreen_dnsbl_threshold</a> 7065 (default: 1)</b></DT><DD> 7066 7067 <p> The inclusive lower bound for blocking an SMTP client, based on 7068 its combined DNSBL score as defined with the <a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> 7069 parameter. </p> 7070 7071 <p> This feature is available in Postfix 2.8. </p> 7072 7073 7074 </DD> 7075 7076 <DT><b><a name="postscreen_dnsbl_ttl">postscreen_dnsbl_ttl</a> 7077 (default: 1h)</b></DT><DD> 7078 7079 <p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from 7080 a successful DNS blocklist test. During this time, the client IP address 7081 is excluded from this test. The default is relatively short, because a 7082 good client can immediately talk to a real Postfix SMTP server. 7083 </p> 7084 7085 <p> Specify a non-zero time value (an integral value plus an optional 7086 one-letter suffix that specifies the time unit). Time units: s 7087 (seconds), m (minutes), h (hours), d (days), w (weeks). </p> 7088 7089 <p> This feature is available in Postfix 2.8. </p> 7090 7091 7092 </DD> 7093 7094 <DT><b><a name="postscreen_enforce_tls">postscreen_enforce_tls</a> 7095 (default: $<a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>)</b></DT><DD> 7096 7097 <p> Mandatory TLS: announce STARTTLS support to SMTP clients, and 7098 require that clients use TLS encryption. See smtpd_postscreen_enforce_tls 7099 for details. </p> 7100 7101 <p> This feature is available in Postfix 2.8 and later. 7102 Preferably, use <a href="postconf.5.html#postscreen_tls_security_level">postscreen_tls_security_level</a> instead. </p> 7103 7104 7105 </DD> 7106 7107 <DT><b><a name="postscreen_expansion_filter">postscreen_expansion_filter</a> 7108 (default: see "postconf -d" output)</b></DT><DD> 7109 7110 <p> List of characters that are permitted in <a href="postconf.5.html#postscreen_reject_footer">postscreen_reject_footer</a> 7111 attribute expansions. See <a href="postconf.5.html#smtpd_expansion_filter">smtpd_expansion_filter</a> for further 7112 details. </p> 7113 7114 <p> This feature is available in Postfix 2.8 and later. </p> 7115 7116 7117 </DD> 7118 7119 <DT><b><a name="postscreen_forbidden_commands">postscreen_forbidden_commands</a> 7120 (default: $<a href="postconf.5.html#smtpd_forbidden_commands">smtpd_forbidden_commands</a>)</b></DT><DD> 7121 7122 <p> List of commands that the <a href="postscreen.8.html">postscreen(8)</a> server considers in 7123 violation of the SMTP protocol. See <a href="postconf.5.html#smtpd_forbidden_commands">smtpd_forbidden_commands</a> for 7124 syntax, and <a href="postconf.5.html#postscreen_non_smtp_command_action">postscreen_non_smtp_command_action</a> for possible actions. 7125 </p> 7126 7127 <p> This feature is available in Postfix 2.8. </p> 7128 7129 7130 </DD> 7131 7132 <DT><b><a name="postscreen_greet_action">postscreen_greet_action</a> 7133 (default: ignore)</b></DT><DD> 7134 7135 <p>The action that <a href="postscreen.8.html">postscreen(8)</a> takes when an SMTP client speaks 7136 before its turn within the time specified with the <a href="postconf.5.html#postscreen_greet_wait">postscreen_greet_wait</a> 7137 parameter. Specify one of the following: </p> 7138 7139 <dl> 7140 7141 <dt> <b>ignore</b> (default) </dt> 7142 7143 <dd> Ignore the failure of this test. Allow other tests to complete. 7144 Repeat this test the next time the client connects. 7145 This option is useful for testing and collecting statistics 7146 without blocking mail. </dd> 7147 7148 <dt> <b>enforce</b> </dt> 7149 7150 <dd> Allow other tests to complete. Reject attempts to deliver mail 7151 with a 550 SMTP reply, and log the helo/sender/recipient information. 7152 Repeat this test the next time the client connects. </dd> 7153 7154 <dt> <b>drop</b> </dt> 7155 7156 <dd> Drop the connection immediately with a 521 SMTP reply. Repeat 7157 this test the next time the client connects. </dd> 7158 7159 </dl> 7160 7161 <p> In either case, <a href="postscreen.8.html">postscreen(8)</a> will not whitelist the SMTP client 7162 IP address. </p> 7163 7164 <p> This feature is available in Postfix 2.8. </p> 7165 7166 7167 </DD> 7168 7169 <DT><b><a name="postscreen_greet_banner">postscreen_greet_banner</a> 7170 (default: $<a href="postconf.5.html#smtpd_banner">smtpd_banner</a>)</b></DT><DD> 7171 7172 <p> The <i>text</i> in the optional "220-<i>text</i>..." server 7173 response that 7174 <a href="postscreen.8.html">postscreen(8)</a> sends ahead of the real Postfix SMTP server's "220 7175 text..." response, in an attempt to confuse bad SMTP clients so 7176 that they speak before their turn (pre-greet). Specify an empty 7177 value to disable this feature. </p> 7178 7179 <p> This feature is available in Postfix 2.8. </p> 7180 7181 7182 </DD> 7183 7184 <DT><b><a name="postscreen_greet_ttl">postscreen_greet_ttl</a> 7185 (default: 1d)</b></DT><DD> 7186 7187 <p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from 7188 a successful PREGREET test. During this time, the client IP address 7189 is excluded from this test. The default is relatively short, because 7190 a good client can immediately talk to a real Postfix SMTP server. </p> 7191 7192 <p> Specify a non-zero time value (an integral value plus an optional 7193 one-letter suffix that specifies the time unit). Time units: s 7194 (seconds), m (minutes), h (hours), d (days), w (weeks). </p> 7195 7196 <p> This feature is available in Postfix 2.8. </p> 7197 7198 7199 </DD> 7200 7201 <DT><b><a name="postscreen_greet_wait">postscreen_greet_wait</a> 7202 (default: ${stress?2}${stress:6}s)</b></DT><DD> 7203 7204 <p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will wait for an SMTP 7205 client to send a command before its turn, and for DNS blocklist 7206 lookup results to arrive (default: up to 2 seconds under stress, 7207 up to 6 seconds otherwise). <p> 7208 7209 <p> Specify a non-zero time value (an integral value plus an optional 7210 one-letter suffix that specifies the time unit). </p> 7211 7212 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 7213 (weeks). </p> 7214 7215 <p> This feature is available in Postfix 2.8. </p> 7216 7217 7218 </DD> 7219 7220 <DT><b><a name="postscreen_helo_required">postscreen_helo_required</a> 7221 (default: $<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a>)</b></DT><DD> 7222 7223 <p> Require that a remote SMTP client sends HELO or EHLO before 7224 commencing a MAIL transaction. </p> 7225 7226 <p> This feature is available in Postfix 2.8. </p> 7227 7228 7229 </DD> 7230 7231 <DT><b><a name="postscreen_non_smtp_command_action">postscreen_non_smtp_command_action</a> 7232 (default: drop)</b></DT><DD> 7233 7234 <p> The action that <a href="postscreen.8.html">postscreen(8)</a> takes when an SMTP client sends 7235 non-SMTP commands as specified with the <a href="postconf.5.html#postscreen_forbidden_commands">postscreen_forbidden_commands</a> 7236 parameter. Specify one of the following: </p> 7237 7238 <dl> 7239 7240 <dt> <b>ignore</b> </dt> 7241 7242 <dd> Ignore the failure of this test. Allow other tests to complete. 7243 Do <i>not</i> repeat this test before some the result from some 7244 other test expires. 7245 This option is useful for testing and collecting statistics 7246 without blocking mail permanently. </dd> 7247 7248 <dt> <b>enforce</b> </dt> 7249 7250 <dd> Allow other tests to complete. Reject attempts to deliver mail 7251 with a 550 SMTP reply, and log the helo/sender/recipient information. 7252 Repeat this test the next time the client connects. </dd> 7253 7254 <dt> <b>drop</b> </dt> 7255 7256 <dd> Drop the connection immediately with a 521 SMTP reply. Repeat 7257 this test the next time the client connects. This action is the 7258 same as with the Postfix SMTP server's <a href="postconf.5.html#smtpd_forbidden_commands">smtpd_forbidden_commands</a> 7259 feature. </dd> 7260 7261 </dl> 7262 7263 <p> This feature is available in Postfix 2.8. </p> 7264 7265 7266 </DD> 7267 7268 <DT><b><a name="postscreen_non_smtp_command_enable">postscreen_non_smtp_command_enable</a> 7269 (default: no)</b></DT><DD> 7270 7271 <p> Enable "non-SMTP command" tests in the <a href="postscreen.8.html">postscreen(8)</a> server. These 7272 tests are expensive: a client must disconnect after it passes the 7273 test, before it can talk to a real Postfix SMTP server. </p> 7274 7275 <p> This feature is available in Postfix 2.8. </p> 7276 7277 7278 </DD> 7279 7280 <DT><b><a name="postscreen_non_smtp_command_ttl">postscreen_non_smtp_command_ttl</a> 7281 (default: 30d)</b></DT><DD> 7282 7283 <p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from 7284 a successful "non_smtp_command" SMTP protocol test. During this 7285 time, the client IP address is excluded from this test. The default 7286 is long because a client must disconnect after it passes the test, 7287 before it can talk to a real Postfix SMTP server. </p> 7288 7289 <p> Specify a non-zero time value (an integral value plus an optional 7290 one-letter suffix that specifies the time unit). Time units: s 7291 (seconds), m (minutes), h (hours), d (days), w (weeks). </p> 7292 7293 <p> This feature is available in Postfix 2.8. </p> 7294 7295 7296 </DD> 7297 7298 <DT><b><a name="postscreen_pipelining_action">postscreen_pipelining_action</a> 7299 (default: enforce)</b></DT><DD> 7300 7301 <p> The action that <a href="postscreen.8.html">postscreen(8)</a> takes when an SMTP client sends 7302 multiple commands instead of sending one command and waiting for 7303 the server to respond. Specify one of the following: </p> 7304 7305 <dl> 7306 7307 <dt> <b>ignore</b> </dt> 7308 7309 <dd> Ignore the failure of this test. Allow other tests to complete. 7310 Do <i>not</i> repeat this test before some the result from some 7311 other test expires. 7312 This option is useful for testing and collecting statistics 7313 without blocking mail permanently. </dd> 7314 7315 <dt> <b>enforce</b> </dt> 7316 7317 <dd> Allow other tests to complete. Reject attempts to deliver mail 7318 with a 550 SMTP reply, and log the helo/sender/recipient information. 7319 Repeat this test the next time the client connects. </dd> 7320 7321 <dt> <b>drop</b> </dt> 7322 7323 <dd> Drop the connection immediately with a 521 SMTP reply. Repeat 7324 this test the next time the client connects. </dd> 7325 7326 </dl> 7327 7328 <p> This feature is available in Postfix 2.8. </p> 7329 7330 7331 </DD> 7332 7333 <DT><b><a name="postscreen_pipelining_enable">postscreen_pipelining_enable</a> 7334 (default: no)</b></DT><DD> 7335 7336 <p> Enable "pipelining" SMTP protocol tests in the <a href="postscreen.8.html">postscreen(8)</a> 7337 server. These tests are expensive: a good client must disconnect 7338 after it passes the test, before it can talk to a real Postfix SMTP 7339 server. </p> 7340 7341 <p> This feature is available in Postfix 2.8. </p> 7342 7343 7344 </DD> 7345 7346 <DT><b><a name="postscreen_pipelining_ttl">postscreen_pipelining_ttl</a> 7347 (default: 30d)</b></DT><DD> 7348 7349 <p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from 7350 a successful "pipelining" SMTP protocol test. During this time, the 7351 client IP address is excluded from this test. The default is 7352 long because a good client must disconnect after it passes the test, 7353 before it can talk to a real Postfix SMTP server. </p> 7354 7355 <p> Specify a non-zero time value (an integral value plus an optional 7356 one-letter suffix that specifies the time unit). Time units: s 7357 (seconds), m (minutes), h (hours), d (days), w (weeks). </p> 7358 7359 <p> This feature is available in Postfix 2.8. </p> 7360 7361 7362 </DD> 7363 7364 <DT><b><a name="postscreen_post_queue_limit">postscreen_post_queue_limit</a> 7365 (default: $<a href="postconf.5.html#default_process_limit">default_process_limit</a>)</b></DT><DD> 7366 7367 <p> The number of clients that can be waiting for service from a 7368 real SMTP server process. When this queue is full, all clients will 7369 receive a 421 reponse. </p> 7370 7371 <p> This feature is available in Postfix 2.8. </p> 7372 7373 7374 </DD> 7375 7376 <DT><b><a name="postscreen_pre_queue_limit">postscreen_pre_queue_limit</a> 7377 (default: $<a href="postconf.5.html#default_process_limit">default_process_limit</a>)</b></DT><DD> 7378 7379 <p> The number of non-whitelisted clients that can be waiting for 7380 a decision whether they will receive service from a real SMTP server 7381 process. When this queue is full, all non-whitelisted clients will 7382 receive a 421 reponse. </p> 7383 7384 <p> This feature is available in Postfix 2.8. </p> 7385 7386 7387 </DD> 7388 7389 <DT><b><a name="postscreen_reject_footer">postscreen_reject_footer</a> 7390 (default: $<a href="postconf.5.html#smtpd_reject_footer">smtpd_reject_footer</a>)</b></DT><DD> 7391 7392 <p> Optional information that is appended after a 4XX or 5XX server 7393 response. See <a href="postconf.5.html#smtpd_reject_footer">smtpd_reject_footer</a> for further details. </p> 7394 7395 <p> This feature is available in Postfix 2.8 and later. </p> 7396 7397 7398 </DD> 7399 7400 <DT><b><a name="postscreen_tls_security_level">postscreen_tls_security_level</a> 7401 (default: $<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a>)</b></DT><DD> 7402 7403 <p> The SMTP TLS security level for the <a href="postscreen.8.html">postscreen(8)</a> server; when 7404 a non-empty value is specified, this overrides the obsolete parameters 7405 <a href="postconf.5.html#postscreen_use_tls">postscreen_use_tls</a> and <a href="postconf.5.html#postscreen_enforce_tls">postscreen_enforce_tls</a>. See <a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> 7406 for details. </p> 7407 7408 <p> This feature is available in Postfix 2.8 and later. </p> 7409 7410 7411 </DD> 7412 7413 <DT><b><a name="postscreen_use_tls">postscreen_use_tls</a> 7414 (default: $<a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a>)</b></DT><DD> 7415 7416 <p> Opportunistic TLS: announce STARTTLS support to SMTP clients, 7417 but do not require that clients use TLS encryption. </p> 7418 7419 <p> This feature is available in Postfix 2.8 and later. 7420 Preferably, use <a href="postconf.5.html#postscreen_tls_security_level">postscreen_tls_security_level</a> instead. </p> 7421 7422 7423 </DD> 7424 7425 <DT><b><a name="postscreen_watchdog_timeout">postscreen_watchdog_timeout</a> 7426 (default: 10s)</b></DT><DD> 7427 7428 <p> How much time a <a href="postscreen.8.html">postscreen(8)</a> process may take to respond to 7429 an SMTP client command or to perform a cache operation before it 7430 is terminated by a built-in watchdog timer. This is a safety 7431 mechanism that prevents <a href="postscreen.8.html">postscreen(8)</a> from becoming non-responsive 7432 due to a bug in Postfix itself or in system software. To avoid 7433 false alarms and unnecessary cache corruption this limit cannot be 7434 set under 10s. </p> 7435 7436 <p> Specify a non-zero time value (an integral value plus an optional 7437 one-letter suffix that specifies the time unit). Time units: s 7438 (seconds), m (minutes), h (hours), d (days), w (weeks). </p> 7439 7440 <p> This feature is available in Postfix 2.8. </p> 7441 7442 7443 </DD> 7444 7445 <DT><b><a name="prepend_delivered_header">prepend_delivered_header</a> 7446 (default: command, file, forward)</b></DT><DD> 7447 7448 <p> The message delivery contexts where the Postfix <a href="local.8.html">local(8)</a> delivery 7449 agent prepends a Delivered-To: message header with the address 7450 that the mail was delivered to. This information is used for mail 7451 delivery loop detection. </p> 7452 7453 <p> 7454 By default, the Postfix local delivery agent prepends a Delivered-To: 7455 header when forwarding mail and when delivering to file (mailbox) 7456 and command. Turning off the Delivered-To: header when forwarding 7457 mail is not recommended. 7458 </p> 7459 7460 <p> 7461 Specify zero or more of <b>forward</b>, <b>file</b>, or <b>command</b>. 7462 </p> 7463 7464 <p> 7465 Example: 7466 </p> 7467 7468 <pre> 7469 <a href="postconf.5.html#prepend_delivered_header">prepend_delivered_header</a> = forward 7470 </pre> 7471 7472 7473 </DD> 7474 7475 <DT><b><a name="process_id">process_id</a> 7476 (read-only)</b></DT><DD> 7477 7478 <p> 7479 The process ID of a Postfix command or daemon process. 7480 </p> 7481 7482 7483 </DD> 7484 7485 <DT><b><a name="process_id_directory">process_id_directory</a> 7486 (default: pid)</b></DT><DD> 7487 7488 <p> 7489 The location of Postfix PID files relative to $<a href="postconf.5.html#queue_directory">queue_directory</a>. 7490 This is a read-only parameter. 7491 </p> 7492 7493 7494 </DD> 7495 7496 <DT><b><a name="process_name">process_name</a> 7497 (read-only)</b></DT><DD> 7498 7499 <p> 7500 The process name of a Postfix command or daemon process. 7501 </p> 7502 7503 7504 </DD> 7505 7506 <DT><b><a name="propagate_unmatched_extensions">propagate_unmatched_extensions</a> 7507 (default: canonical, virtual)</b></DT><DD> 7508 7509 <p> 7510 What address lookup tables copy an address extension from the lookup 7511 key to the lookup result. 7512 </p> 7513 7514 <p> 7515 For example, with a <a href="virtual.5.html">virtual(5)</a> mapping of "<i>joe (a] example.com => 7516 joe.user (a] example.net</i>", the address "<i>joe+foo (a] example.com</i>" 7517 would rewrite to "<i>joe.user+foo (a] example.net</i>". 7518 </p> 7519 7520 <p> 7521 Specify zero or more of <b>canonical</b>, <b>virtual</b>, <b>alias</b>, 7522 <b>forward</b>, <b>include</b> or <b>generic</b>. These cause 7523 address extension 7524 propagation with <a href="canonical.5.html">canonical(5)</a>, <a href="virtual.5.html">virtual(5)</a>, and <a href="aliases.5.html">aliases(5)</a> maps, 7525 with <a href="local.8.html">local(8)</a> .forward and :include: file lookups, and with <a href="smtp.8.html">smtp(8)</a> 7526 generic maps, respectively. </p> 7527 7528 <p> 7529 Note: enabling this feature for types other than <b>canonical</b> 7530 and <b>virtual</b> is likely to cause problems when mail is forwarded 7531 to other sites, especially with mail that is sent to a mailing list 7532 exploder address. 7533 </p> 7534 7535 <p> 7536 Examples: 7537 </p> 7538 7539 <pre> 7540 <a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> = canonical, virtual, alias, 7541 forward, include 7542 <a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> = canonical, virtual 7543 </pre> 7544 7545 7546 </DD> 7547 7548 <DT><b><a name="proxy_interfaces">proxy_interfaces</a> 7549 (default: empty)</b></DT><DD> 7550 7551 <p> 7552 The network interface addresses that this mail system receives mail 7553 on by way of a proxy or network address translation unit. 7554 </p> 7555 7556 <p> 7557 This feature is available in Postfix 2.0 and later. 7558 </p> 7559 7560 <p> You must specify your "outside" proxy/NAT addresses when your 7561 system is a backup MX host for other domains, otherwise mail delivery 7562 loops will happen when the primary MX host is down. </p> 7563 7564 <p> 7565 Example: 7566 </p> 7567 7568 <pre> 7569 <a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> = 1.2.3.4 7570 </pre> 7571 7572 7573 </DD> 7574 7575 <DT><b><a name="proxy_read_maps">proxy_read_maps</a> 7576 (default: see "postconf -d" output)</b></DT><DD> 7577 7578 <p> 7579 The lookup tables that the <a href="proxymap.8.html">proxymap(8)</a> server is allowed to 7580 access for the read-only service. 7581 Table references that don't begin with <a href="proxymap.8.html">proxy</a>: are ignored. 7582 </p> 7583 7584 <p> 7585 This feature is available in Postfix 2.0 and later. 7586 </p> 7587 7588 7589 </DD> 7590 7591 <DT><b><a name="proxy_write_maps">proxy_write_maps</a> 7592 (default: see "postconf -d" output)</b></DT><DD> 7593 7594 <p> The lookup tables that the <a href="proxymap.8.html">proxymap(8)</a> server is allowed to 7595 access for the read-write service. Postfix-owned local database 7596 files should be stored under the Postfix-owned <a href="postconf.5.html#data_directory">data_directory</a>. 7597 Table references that don't begin with <a href="proxymap.8.html">proxy</a>: are ignored. </p> 7598 7599 <p> 7600 This feature is available in Postfix 2.5 and later. 7601 </p> 7602 7603 7604 </DD> 7605 7606 <DT><b><a name="proxymap_service_name">proxymap_service_name</a> 7607 (default: proxymap)</b></DT><DD> 7608 7609 <p> The name of the proxymap read-only table lookup service. This 7610 service is normally implemented by the <a href="proxymap.8.html">proxymap(8)</a> daemon. </p> 7611 7612 <p> This feature is available in Postfix 2.6 and later. </p> 7613 7614 7615 </DD> 7616 7617 <DT><b><a name="proxywrite_service_name">proxywrite_service_name</a> 7618 (default: proxywrite)</b></DT><DD> 7619 7620 <p> The name of the proxywrite read-write table lookup service. 7621 This service is normally implemented by the <a href="proxymap.8.html">proxymap(8)</a> daemon. 7622 </p> 7623 7624 <p> This feature is available in Postfix 2.6 and later. </p> 7625 7626 7627 </DD> 7628 7629 <DT><b><a name="qmgr_clog_warn_time">qmgr_clog_warn_time</a> 7630 (default: 300s)</b></DT><DD> 7631 7632 <p> 7633 The minimal delay between warnings that a specific destination is 7634 clogging up the Postfix <a href="QSHAPE_README.html#active_queue">active queue</a>. Specify 0 to disable. 7635 </p> 7636 7637 <p> 7638 This feature is enabled with the <a href="postconf.5.html#helpful_warnings">helpful_warnings</a> parameter. 7639 </p> 7640 7641 <p> 7642 This feature is available in Postfix 2.0 and later. 7643 </p> 7644 7645 7646 </DD> 7647 7648 <DT><b><a name="qmgr_daemon_timeout">qmgr_daemon_timeout</a> 7649 (default: 1000s)</b></DT><DD> 7650 7651 <p> How much time a Postfix queue manager process may take to handle 7652 a request before it is terminated by a built-in watchdog timer. 7653 </p> 7654 7655 <p> 7656 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7657 The default time unit is s (seconds). 7658 </p> 7659 7660 <p> This feature is available in Postfix 2.8 and later. </p> 7661 7662 7663 </DD> 7664 7665 <DT><b><a name="qmgr_fudge_factor">qmgr_fudge_factor</a> 7666 (default: 100)</b></DT><DD> 7667 7668 <p> 7669 Obsolete feature: the percentage of delivery resources that a busy 7670 mail system will use up for delivery of a large mailing list 7671 message. 7672 </p> 7673 7674 <p> 7675 This feature exists only in the <a href="qmgr.8.html">oqmgr(8)</a> old queue manager. The 7676 current queue manager solves the problem in a better way. 7677 </p> 7678 7679 7680 </DD> 7681 7682 <DT><b><a name="qmgr_ipc_timeout">qmgr_ipc_timeout</a> 7683 (default: 60s)</b></DT><DD> 7684 7685 <p> The time limit for the queue manager to send or receive information 7686 over an internal communication channel. The purpose is to break 7687 out of deadlock situations. If the time limit is exceeded the 7688 software either retries or aborts the operation. </p> 7689 7690 <p> 7691 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7692 The default time unit is s (seconds). 7693 </p> 7694 7695 <p> This feature is available in Postfix 2.8 and later. </p> 7696 7697 7698 </DD> 7699 7700 <DT><b><a name="qmgr_message_active_limit">qmgr_message_active_limit</a> 7701 (default: 20000)</b></DT><DD> 7702 7703 <p> 7704 The maximal number of messages in the <a href="QSHAPE_README.html#active_queue">active queue</a>. 7705 </p> 7706 7707 7708 </DD> 7709 7710 <DT><b><a name="qmgr_message_recipient_limit">qmgr_message_recipient_limit</a> 7711 (default: 20000)</b></DT><DD> 7712 7713 <p> The maximal number of recipients held in memory by the Postfix 7714 queue manager, and the maximal size of the size of the short-term, 7715 in-memory "dead" destination status cache. </p> 7716 7717 7718 </DD> 7719 7720 <DT><b><a name="qmgr_message_recipient_minimum">qmgr_message_recipient_minimum</a> 7721 (default: 10)</b></DT><DD> 7722 7723 <p> 7724 The minimal number of in-memory recipients for any message. This 7725 takes priority over any other in-memory recipient limits (i.e., 7726 the global <a href="postconf.5.html#qmgr_message_recipient_limit">qmgr_message_recipient_limit</a> and the per transport 7727 _recipient_limit) if necessary. The minimum value allowed for this 7728 parameter is 1. 7729 </p> 7730 7731 7732 </DD> 7733 7734 <DT><b><a name="qmqpd_authorized_clients">qmqpd_authorized_clients</a> 7735 (default: empty)</b></DT><DD> 7736 7737 <p> 7738 What clients are allowed to connect to the QMQP server port. 7739 </p> 7740 7741 <p> 7742 By default, no client is allowed to use the service. This is 7743 because the QMQP server will relay mail to any destination. 7744 </p> 7745 7746 <p> 7747 Specify a list of client patterns. A list pattern specifies a host 7748 name, a domain name, an internet address, or a network/mask pattern, 7749 where the mask specifies the number of bits in the network part. 7750 When a pattern specifies a file name, its contents are substituted 7751 for the file name; when a pattern is a "<a href="DATABASE_README.html">type:table</a>" table specification, 7752 table lookup is used instead. </p> 7753 7754 <p> 7755 Patterns are separated by whitespace and/or commas. In order to 7756 reverse the result, precede a pattern with an 7757 exclamation point (!). The form "!/file/name" is supported only 7758 in Postfix version 2.4 and later. 7759 </p> 7760 7761 <p> 7762 Example: 7763 </p> 7764 7765 <pre> 7766 <a href="postconf.5.html#qmqpd_authorized_clients">qmqpd_authorized_clients</a> = !192.168.0.1, 192.168.0.0/24 7767 </pre> 7768 7769 7770 </DD> 7771 7772 <DT><b><a name="qmqpd_client_port_logging">qmqpd_client_port_logging</a> 7773 (default: no)</b></DT><DD> 7774 7775 <p> Enable logging of the remote QMQP client port in addition to 7776 the hostname and IP address. The logging format is "host[address]:port". 7777 </p> 7778 7779 <p> This feature is available in Postfix 2.5 and later. </p> 7780 7781 7782 </DD> 7783 7784 <DT><b><a name="qmqpd_error_delay">qmqpd_error_delay</a> 7785 (default: 1s)</b></DT><DD> 7786 7787 <p> 7788 How long the QMQP server will pause before sending a negative reply 7789 to the client. The purpose is to slow down confused or malicious 7790 clients. 7791 </p> 7792 7793 <p> 7794 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7795 The default time unit is s (seconds). 7796 </p> 7797 7798 7799 </DD> 7800 7801 <DT><b><a name="qmqpd_timeout">qmqpd_timeout</a> 7802 (default: 300s)</b></DT><DD> 7803 7804 <p> 7805 The time limit for sending or receiving information over the network. 7806 If a read or write operation blocks for more than $<a href="postconf.5.html#qmqpd_timeout">qmqpd_timeout</a> 7807 seconds the QMQP server gives up and disconnects. 7808 </p> 7809 7810 <p> 7811 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7812 The default time unit is s (seconds). 7813 </p> 7814 7815 7816 </DD> 7817 7818 <DT><b><a name="queue_directory">queue_directory</a> 7819 (default: see "postconf -d" output)</b></DT><DD> 7820 7821 <p> 7822 The location of the Postfix top-level queue directory. This is the 7823 root directory of Postfix daemon processes that run chrooted. 7824 </p> 7825 7826 7827 </DD> 7828 7829 <DT><b><a name="queue_file_attribute_count_limit">queue_file_attribute_count_limit</a> 7830 (default: 100)</b></DT><DD> 7831 7832 <p> 7833 The maximal number of (name=value) attributes that may be stored 7834 in a Postfix queue file. The limit is enforced by the <a href="cleanup.8.html">cleanup(8)</a> 7835 server. 7836 </p> 7837 7838 <p> 7839 This feature is available in Postfix 2.0 and later. 7840 </p> 7841 7842 7843 </DD> 7844 7845 <DT><b><a name="queue_minfree">queue_minfree</a> 7846 (default: 0)</b></DT><DD> 7847 7848 <p> 7849 The minimal amount of free space in bytes in the queue file system 7850 that is needed to receive mail. This is currently used by the SMTP 7851 server to decide if it will accept any mail at all. 7852 </p> 7853 7854 <p> 7855 By default, the Postfix SMTP server rejects MAIL FROM commands when 7856 the amount of free space is less than 1.5*$<a href="postconf.5.html#message_size_limit">message_size_limit</a> 7857 (Postfix version 2.1 and later). 7858 To specify a higher minimum free space limit, specify a <a href="postconf.5.html#queue_minfree">queue_minfree</a> 7859 value that is at least 1.5*$<a href="postconf.5.html#message_size_limit">message_size_limit</a>. 7860 </p> 7861 7862 <p> 7863 With Postfix versions 2.0 and earlier, a <a href="postconf.5.html#queue_minfree">queue_minfree</a> value of 7864 zero means there is no minimum required amount of free space. 7865 </p> 7866 7867 7868 </DD> 7869 7870 <DT><b><a name="queue_run_delay">queue_run_delay</a> 7871 (default: 300s)</b></DT><DD> 7872 7873 <p> 7874 The time between <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> scans by the queue manager; 7875 prior to Postfix 2.4 the default value was 1000s. 7876 </p> 7877 7878 <p> This parameter should be set less than or equal to 7879 $<a href="postconf.5.html#minimal_backoff_time">minimal_backoff_time</a>. See also $<a href="postconf.5.html#maximal_backoff_time">maximal_backoff_time</a>. </p> 7880 7881 <p> 7882 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7883 The default time unit is s (seconds). 7884 </p> 7885 7886 7887 </DD> 7888 7889 <DT><b><a name="queue_service_name">queue_service_name</a> 7890 (default: qmgr)</b></DT><DD> 7891 7892 <p> 7893 The name of the <a href="qmgr.8.html">qmgr(8)</a> service. This service manages the Postfix 7894 queue and schedules delivery requests. 7895 </p> 7896 7897 <p> 7898 This feature is available in Postfix 2.0 and later. 7899 </p> 7900 7901 7902 </DD> 7903 7904 <DT><b><a name="rbl_reply_maps">rbl_reply_maps</a> 7905 (default: empty)</b></DT><DD> 7906 7907 <p> 7908 Optional lookup tables with RBL response templates. The tables are 7909 indexed by the RBL domain name. By default, Postfix uses the default 7910 template as specified with the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> configuration 7911 parameter. See there for a discussion of the syntax of RBL reply 7912 templates. 7913 </p> 7914 7915 <p> 7916 This feature is available in Postfix 2.0 and later. 7917 </p> 7918 7919 7920 </DD> 7921 7922 <DT><b><a name="readme_directory">readme_directory</a> 7923 (default: see "postconf -d" output)</b></DT><DD> 7924 7925 <p> 7926 The location of Postfix README files that describe how to build, 7927 configure or operate a specific Postfix subsystem or feature. 7928 </p> 7929 7930 7931 </DD> 7932 7933 <DT><b><a name="receive_override_options">receive_override_options</a> 7934 (default: empty)</b></DT><DD> 7935 7936 <p> Enable or disable recipient validation, built-in content 7937 filtering, or address mapping. Typically, these are specified in 7938 <a href="master.5.html">master.cf</a> as command-line arguments for the <a href="smtpd.8.html">smtpd(8)</a>, <a href="qmqpd.8.html">qmqpd(8)</a> or 7939 <a href="pickup.8.html">pickup(8)</a> daemons. </p> 7940 7941 <p> Specify zero or more of the following options. The options 7942 override <a href="postconf.5.html">main.cf</a> settings and are either implemented by <a href="smtpd.8.html">smtpd(8)</a>, 7943 <a href="qmqpd.8.html">qmqpd(8)</a>, or <a href="pickup.8.html">pickup(8)</a> themselves, or they are forwarded to the 7944 cleanup server. </p> 7945 7946 <dl> 7947 7948 <dt><b><a name="no_unknown_recipient_checks">no_unknown_recipient_checks</a></b></dt> 7949 7950 <dd>Do not try to reject unknown recipients (SMTP server only). 7951 This is typically specified AFTER an external content filter. 7952 </dd> 7953 7954 <dt><b><a name="no_address_mappings">no_address_mappings</a></b></dt> 7955 7956 <dd>Disable canonical address mapping, virtual alias map expansion, 7957 address masquerading, and automatic BCC (blind carbon-copy) 7958 recipients. This is typically specified BEFORE an external content 7959 filter. </dd> 7960 7961 <dt><b><a name="no_header_body_checks">no_header_body_checks</a></b></dt> 7962 7963 <dd>Disable header/body_checks. This is typically specified AFTER 7964 an external content filter. </dd> 7965 7966 <dt><b><a name="no_milters">no_milters</a></b></dt> 7967 7968 <dd>Disable Milter (mail filter) applications. This is typically 7969 specified AFTER an external content filter. </dd> 7970 7971 </dl> 7972 7973 <p> 7974 Note: when the "BEFORE content filter" <a href="postconf.5.html#receive_override_options">receive_override_options</a> 7975 setting is specified in the <a href="postconf.5.html">main.cf</a> file, specify the "AFTER content 7976 filter" <a href="postconf.5.html#receive_override_options">receive_override_options</a> setting in <a href="master.5.html">master.cf</a> (and vice 7977 versa). 7978 </p> 7979 7980 <p> 7981 Examples: 7982 </p> 7983 7984 <pre> 7985 <a href="postconf.5.html#receive_override_options">receive_override_options</a> = 7986 <a href="postconf.5.html#no_unknown_recipient_checks">no_unknown_recipient_checks</a>, <a href="postconf.5.html#no_header_body_checks">no_header_body_checks</a> 7987 <a href="postconf.5.html#receive_override_options">receive_override_options</a> = <a href="postconf.5.html#no_address_mappings">no_address_mappings</a> 7988 </pre> 7989 7990 <p> 7991 This feature is available in Postfix 2.1 and later. 7992 </p> 7993 7994 7995 </DD> 7996 7997 <DT><b><a name="recipient_bcc_maps">recipient_bcc_maps</a> 7998 (default: empty)</b></DT><DD> 7999 8000 <p> 8001 Optional BCC (blind carbon-copy) address lookup tables, indexed by 8002 recipient address. The BCC address (multiple results are not 8003 supported) is added when mail enters from outside of Postfix. 8004 </p> 8005 8006 <p> 8007 This feature is available in Postfix 2.1 and later. 8008 </p> 8009 8010 <p> 8011 The table search order is as follows: 8012 </p> 8013 8014 <ul> 8015 8016 <li> Look up the "user+extension (a] domain.tld" address including the 8017 optional address extension. 8018 8019 <li> Look up the "user (a] domain.tld" address without the optional 8020 address extension. 8021 8022 <li> Look up the "user+extension" address local part when the 8023 recipient domain equals $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> 8024 or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. 8025 8026 <li> Look up the "user" address local part when the recipient domain 8027 equals $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. 8028 8029 <li> Look up the "@domain.tld" part. 8030 8031 </ul> 8032 8033 <p> 8034 Specify the types and names of databases to use. After change, 8035 run "<b>postmap /etc/postfix/recipient_bcc</b>". 8036 </p> 8037 8038 <p> 8039 Note: if mail to the BCC address bounces it will be returned to 8040 the sender. 8041 </p> 8042 8043 <p> Note: automatic BCC recipients are produced only for new mail. 8044 To avoid mailer loops, automatic BCC recipients are not generated 8045 after Postfix forwards mail internally, or after Postfix generates 8046 mail itself. </p> 8047 8048 <p> 8049 Example: 8050 </p> 8051 8052 <pre> 8053 <a href="postconf.5.html#recipient_bcc_maps">recipient_bcc_maps</a> = hash:/etc/postfix/recipient_bcc 8054 </pre> 8055 8056 8057 </DD> 8058 8059 <DT><b><a name="recipient_canonical_classes">recipient_canonical_classes</a> 8060 (default: envelope_recipient, header_recipient)</b></DT><DD> 8061 8062 <p> What addresses are subject to <a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> address 8063 mapping. By default, <a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> address mapping is 8064 applied to envelope recipient addresses, and to header recipient 8065 addresses. </p> 8066 8067 <p> Specify one or more of: envelope_recipient, header_recipient 8068 </p> 8069 8070 <p> This feature is available in Postfix 2.2 and later. </p> 8071 8072 8073 </DD> 8074 8075 <DT><b><a name="recipient_canonical_maps">recipient_canonical_maps</a> 8076 (default: empty)</b></DT><DD> 8077 8078 <p> 8079 Optional address mapping lookup tables for envelope and header 8080 recipient addresses. 8081 The table format and lookups are documented in <a href="canonical.5.html">canonical(5)</a>. 8082 </p> 8083 8084 <p> 8085 Note: $<a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> is processed before $<a href="postconf.5.html#canonical_maps">canonical_maps</a>. 8086 </p> 8087 8088 <p> 8089 Example: 8090 </p> 8091 8092 <pre> 8093 <a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> = hash:/etc/postfix/recipient_canonical 8094 </pre> 8095 8096 8097 </DD> 8098 8099 <DT><b><a name="recipient_delimiter">recipient_delimiter</a> 8100 (default: empty)</b></DT><DD> 8101 8102 <p> 8103 The separator between user names and address extensions (user+foo). 8104 See <a href="canonical.5.html">canonical(5)</a>, <a href="local.8.html">local(8)</a>, <a href="relocated.5.html">relocated(5)</a> and <a href="virtual.5.html">virtual(5)</a> for the 8105 effects this has on aliases, canonical, virtual, relocated and 8106 on .forward file lookups. Basically, the software tries user+foo 8107 and .forward+foo before trying user and .forward. 8108 </p> 8109 8110 <p> 8111 Example: 8112 </p> 8113 8114 <pre> 8115 <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> = + 8116 </pre> 8117 8118 8119 </DD> 8120 8121 <DT><b><a name="reject_code">reject_code</a> 8122 (default: 554)</b></DT><DD> 8123 8124 <p> 8125 The numerical Postfix SMTP server response code when a remote SMTP 8126 client request is rejected by the "reject" restriction. 8127 </p> 8128 8129 <p> 8130 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 8131 </p> 8132 8133 8134 </DD> 8135 8136 <DT><b><a name="reject_tempfail_action">reject_tempfail_action</a> 8137 (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>)</b></DT><DD> 8138 8139 <p> The Postfix SMTP server's action when a reject-type restriction 8140 fails due to a temporary error condition. Specify "defer" to defer 8141 the remote SMTP client request immediately. With the default 8142 "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look 8143 for opportunities to reject mail, and defers the client request 8144 only if it would otherwise be accepted. </p> 8145 8146 <p> For finer control, see: <a href="postconf.5.html#unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a>, 8147 <a href="postconf.5.html#unverified_sender_tempfail_action">unverified_sender_tempfail_action</a>, <a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a>, 8148 and <a href="postconf.5.html#unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a>. </p> 8149 8150 <p> This feature is available in Postfix 2.6 and later. </p> 8151 8152 8153 </DD> 8154 8155 <DT><b><a name="relay_clientcerts">relay_clientcerts</a> 8156 (default: empty)</b></DT><DD> 8157 8158 <p> List of tables with remote SMTP client-certificate fingerprints 8159 for which the Postfix SMTP server will allow access with the 8160 <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> feature. 8161 The fingerprint digest algorithm is configurable via the 8162 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to 8163 Postfix version 2.5). </p> 8164 8165 <p> Postfix lookup tables are in the form of (key, value) pairs. 8166 Since we only need the key, the value can be chosen freely, e.g. 8167 the name of the user or host: 8168 D7:04:2F:A7:0B:8C:A5:21:FA:31:77:E1:41:8A:EE:80 lutzpc.at.home </p> 8169 8170 <p> Example: </p> 8171 8172 <pre> 8173 <a href="postconf.5.html#relay_clientcerts">relay_clientcerts</a> = hash:/etc/postfix/relay_clientcerts 8174 </pre> 8175 8176 <p>For more fine-grained control, use <a href="postconf.5.html#check_ccert_access">check_ccert_access</a> to select 8177 an appropriate <a href="access.5.html">access(5)</a> policy for each client. 8178 See <a href="RESTRICTION_CLASS_README.html">RESTRICTION_CLASS_README</a>.</p> 8179 8180 <p>This feature is available with Postfix version 2.2.</p> 8181 8182 8183 </DD> 8184 8185 <DT><b><a name="relay_destination_concurrency_limit">relay_destination_concurrency_limit</a> 8186 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 8187 8188 <p> The maximal number of parallel deliveries to the same destination 8189 via the relay message delivery transport. This limit is enforced 8190 by the queue manager. The message delivery transport name is the 8191 first field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 8192 8193 <p> This feature is available in Postfix 2.0 and later. </p> 8194 8195 8196 </DD> 8197 8198 <DT><b><a name="relay_destination_recipient_limit">relay_destination_recipient_limit</a> 8199 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 8200 8201 <p> The maximal number of recipients per message for the relay 8202 message delivery transport. This limit is enforced by the queue 8203 manager. The message delivery transport name is the first field in 8204 the entry in the <a href="master.5.html">master.cf</a> file. </p> 8205 8206 <p> Setting this parameter to a value of 1 changes the meaning of 8207 <a href="postconf.5.html#relay_destination_concurrency_limit">relay_destination_concurrency_limit</a> from concurrency per domain 8208 into concurrency per recipient. </p> 8209 8210 <p> This feature is available in Postfix 2.0 and later. </p> 8211 8212 8213 </DD> 8214 8215 <DT><b><a name="relay_domains">relay_domains</a> 8216 (default: $<a href="postconf.5.html#mydestination">mydestination</a>)</b></DT><DD> 8217 8218 <p> What destination domains (and subdomains thereof) this system 8219 will relay mail to. Subdomain matching is controlled with the 8220 <a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> parameter. For details about how 8221 the <a href="postconf.5.html#relay_domains">relay_domains</a> value is used, see the description of the 8222 <a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a> and <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> SMTP recipient 8223 restrictions. </p> 8224 8225 <p> Domains that match $<a href="postconf.5.html#relay_domains">relay_domains</a> are delivered with the 8226 $<a href="postconf.5.html#relay_transport">relay_transport</a> mail delivery transport. The SMTP server validates 8227 recipient addresses with $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> and rejects non-existent 8228 recipients. See also the <a href="ADDRESS_CLASS_README.html#relay_domain_class">relay domains</a> address class in the 8229 <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file. </p> 8230 8231 <p> Note: Postfix will not automatically forward mail for domains 8232 that list this system as their primary or backup MX host. See the 8233 <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> restriction in the <a href="postconf.5.html">postconf(5)</a> manual page. </p> 8234 8235 <p> Specify a list of host or domain names, "/file/name" patterns 8236 or "<a href="DATABASE_README.html">type:table</a>" lookup tables, separated by commas and/or whitespace. 8237 Continue long lines by starting the next line with whitespace. A 8238 "/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" 8239 lookup table is matched when a (parent) domain appears as lookup 8240 key. Specify "!pattern" to exclude a domain from the list. The form 8241 "!/file/name" is supported only in Postfix version 2.4 and later. 8242 </p> 8243 8244 8245 </DD> 8246 8247 <DT><b><a name="relay_domains_reject_code">relay_domains_reject_code</a> 8248 (default: 554)</b></DT><DD> 8249 8250 <p> 8251 The numerical Postfix SMTP server response code when a client 8252 request is rejected by the <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> recipient 8253 restriction. 8254 </p> 8255 8256 <p> 8257 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 8258 </p> 8259 8260 8261 </DD> 8262 8263 <DT><b><a name="relay_recipient_maps">relay_recipient_maps</a> 8264 (default: empty)</b></DT><DD> 8265 8266 <p> Optional lookup tables with all valid addresses in the domains 8267 that match $<a href="postconf.5.html#relay_domains">relay_domains</a>. Specify @domain as a wild-card for 8268 domains that have no valid recipient list, and become a source of 8269 backscatter mail: Postfix accepts spam for non-existent recipients 8270 and then floods innocent people with undeliverable mail. Technically, 8271 tables 8272 listed with $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> are used as lists: Postfix needs 8273 to know only if a lookup string is found or not, but it does not 8274 use the result from table lookup. </p> 8275 8276 <p> 8277 If this parameter is non-empty, then the Postfix SMTP server will reject 8278 mail to unknown relay users. This feature is off by default. 8279 </p> 8280 8281 <p> 8282 See also the <a href="ADDRESS_CLASS_README.html#relay_domain_class">relay domains</a> address class in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> 8283 file. 8284 </p> 8285 8286 <p> 8287 Example: 8288 </p> 8289 8290 <pre> 8291 <a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> = hash:/etc/postfix/relay_recipients 8292 </pre> 8293 8294 <p> 8295 This feature is available in Postfix 2.0 and later. 8296 </p> 8297 8298 8299 </DD> 8300 8301 <DT><b><a name="relay_transport">relay_transport</a> 8302 (default: relay)</b></DT><DD> 8303 8304 <p> 8305 The default mail delivery transport and next-hop destination for 8306 remote delivery to domains listed with $<a href="postconf.5.html#relay_domains">relay_domains</a>. In order of 8307 decreasing precedence, the nexthop destination is taken from 8308 $<a href="postconf.5.html#relay_transport">relay_transport</a>, $<a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>, $<a href="postconf.5.html#relayhost">relayhost</a>, or 8309 from the recipient domain. This information can be overruled with 8310 the <a href="transport.5.html">transport(5)</a> table. 8311 </p> 8312 8313 <p> 8314 Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i> 8315 is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>. 8316 The <i>:nexthop</i> destination is optional; its syntax is documented 8317 in the manual page of the corresponding delivery agent. 8318 </p> 8319 8320 <p> 8321 See also the <a href="ADDRESS_CLASS_README.html#relay_domain_class">relay domains</a> address class in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> 8322 file. 8323 </p> 8324 8325 <p> 8326 This feature is available in Postfix 2.0 and later. 8327 </p> 8328 8329 8330 </DD> 8331 8332 <DT><b><a name="relayhost">relayhost</a> 8333 (default: empty)</b></DT><DD> 8334 8335 <p> 8336 The next-hop destination of non-local mail; overrides non-local 8337 domains in recipient addresses. This information is overruled with 8338 <a href="postconf.5.html#relay_transport">relay_transport</a>, <a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a>, 8339 <a href="postconf.5.html#default_transport">default_transport</a>, <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> 8340 and with the <a href="transport.5.html">transport(5)</a> table. 8341 </p> 8342 8343 <p> 8344 On an intranet, specify the organizational domain name. If your 8345 internal DNS uses no MX records, specify the name of the intranet 8346 gateway host instead. 8347 </p> 8348 8349 <p> 8350 In the case of SMTP, specify a domain name, hostname, hostname:port, 8351 [hostname]:port, [hostaddress] or [hostaddress]:port. The form 8352 [hostname] turns off MX lookups. 8353 </p> 8354 8355 <p> 8356 If you're connected via UUCP, see the <a href="UUCP_README.html">UUCP_README</a> file for useful 8357 information. 8358 </p> 8359 8360 <p> 8361 Examples: 8362 </p> 8363 8364 <pre> 8365 <a href="postconf.5.html#relayhost">relayhost</a> = $<a href="postconf.5.html#mydomain">mydomain</a> 8366 <a href="postconf.5.html#relayhost">relayhost</a> = [gateway.example.com] 8367 <a href="postconf.5.html#relayhost">relayhost</a> = uucphost 8368 <a href="postconf.5.html#relayhost">relayhost</a> = [an.ip.add.ress] 8369 </pre> 8370 8371 8372 </DD> 8373 8374 <DT><b><a name="relocated_maps">relocated_maps</a> 8375 (default: empty)</b></DT><DD> 8376 8377 <p> 8378 Optional lookup tables with new contact information for users or 8379 domains that no longer exist. The table format and lookups are 8380 documented in <a href="relocated.5.html">relocated(5)</a>. 8381 </p> 8382 8383 <p> 8384 If you use this feature, run "<b>postmap /etc/postfix/relocated</b>" to 8385 build the necessary DBM or DB file after change, then "<b>postfix 8386 reload</b>" to make the changes visible. 8387 </p> 8388 8389 <p> 8390 Examples: 8391 </p> 8392 8393 <pre> 8394 <a href="postconf.5.html#relocated_maps">relocated_maps</a> = dbm:/etc/postfix/relocated 8395 <a href="postconf.5.html#relocated_maps">relocated_maps</a> = hash:/etc/postfix/relocated 8396 </pre> 8397 8398 8399 </DD> 8400 8401 <DT><b><a name="remote_header_rewrite_domain">remote_header_rewrite_domain</a> 8402 (default: empty)</b></DT><DD> 8403 8404 <p> Don't rewrite message headers from remote clients at all when 8405 this parameter is empty; otherwise, rewrite message headers and 8406 append the specified domain name to incomplete addresses. The 8407 <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> parameter controls what clients Postfix 8408 considers local. </p> 8409 8410 <p> Examples: </p> 8411 8412 <p> The safe setting: append "domain.invalid" to incomplete header 8413 addresses from remote SMTP clients, so that those addresses cannot 8414 be confused with local addresses. </p> 8415 8416 <blockquote> 8417 <pre> 8418 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> = domain.invalid 8419 </pre> 8420 </blockquote> 8421 8422 <p> The default, purist, setting: don't rewrite headers from remote 8423 clients at all. </p> 8424 8425 <blockquote> 8426 <pre> 8427 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> = 8428 </pre> 8429 </blockquote> 8430 8431 8432 </DD> 8433 8434 <DT><b><a name="require_home_directory">require_home_directory</a> 8435 (default: no)</b></DT><DD> 8436 8437 <p> 8438 Require that a <a href="local.8.html">local(8)</a> recipient's home directory exists 8439 before mail delivery is attempted. By default this test is disabled. 8440 It can be useful for environments that import home directories to 8441 the mail server (IMPORTING HOME DIRECTORIES IS NOT RECOMMENDED). 8442 </p> 8443 8444 8445 </DD> 8446 8447 <DT><b><a name="reset_owner_alias">reset_owner_alias</a> 8448 (default: no)</b></DT><DD> 8449 8450 <p> Reset the <a href="local.8.html">local(8)</a> delivery agent's idea of the owner-alias 8451 attribute, when delivering mail to a child alias that does not have 8452 its own owner alias. </p> 8453 8454 <p> This feature is available in Postfix 2.8 and later. With older 8455 Postfix releases, the behavior is as if this parameter is set to 8456 "yes". </p> 8457 8458 <p> As documented in <a href="aliases.5.html">aliases(5)</a>, when an alias <i>name</i> has a 8459 companion alias named owner-<i>name</i>, delivery errors will be 8460 reported to the owner alias instead of the sender. This configuration 8461 is recommended for mailing lists. <p> 8462 8463 <p> A less known property of the owner alias is that it also forces 8464 the <a href="local.8.html">local(8)</a> delivery agent to write local and remote addresses 8465 from alias expansion to a new queue file, instead of attempting to 8466 deliver mail to local addresses as soon as they come out of alias 8467 expansion. </p> 8468 8469 <p> Writing local addresses from alias expansion to a new queue 8470 file allows for robust handling of temporary delivery errors: errors 8471 with one local member have no effect on deliveries to other members 8472 of the list. On the other hand, delivery to local addresses as 8473 soon as they come out of alias expansion is fragile: a temporary 8474 error with one local address from alias expansion will cause the 8475 entire alias to be expanded repeatedly until the error goes away, 8476 or until the message expires in the queue. In that case, a problem 8477 with one list member results in multiple message deliveries to other 8478 list members. </p> 8479 8480 <p> The default behavior of Postfix 2.8 and later is to keep the 8481 owner-alias attribute of the parent alias, when delivering mail to 8482 a child alias that does not have its own owner alias. Then, local 8483 addresses from that child alias will be written to a new queue file, 8484 and a temporary error with one local address will not affect delivery 8485 to other mailing list members. </p> 8486 8487 <p> Unfortunately, older Postfix releases reset the owner-alias 8488 attribute when delivering mail to a child alias that does not have 8489 its own owner alias. The <a href="local.8.html">local(8)</a> delivery agent then attempts to 8490 deliver local addresses as soon as they come out of child alias 8491 expansion. If delivery to any address from child alias expansion 8492 fails with a temporary error condition, the entire mailing list may 8493 be expanded repeatedly until the mail expires in the queue, resulting 8494 in multiple deliveries of the same message to mailing list members. 8495 </p> 8496 8497 8498 </DD> 8499 8500 <DT><b><a name="resolve_dequoted_address">resolve_dequoted_address</a> 8501 (default: yes)</b></DT><DD> 8502 8503 <p> Resolve a recipient address safely instead of correctly, by 8504 looking inside quotes. </p> 8505 8506 <p> By default, the Postfix address resolver does not quote the 8507 address localpart as per <a href="http://tools.ietf.org/html/rfc822">RFC 822</a>, so that additional @ or % or ! 8508 operators remain visible. This behavior is safe but it is also 8509 technically incorrect. </p> 8510 8511 <p> If you specify "<a href="postconf.5.html#resolve_dequoted_address">resolve_dequoted_address</a> = no", then 8512 the Postfix 8513 resolver will not know about additional @ etc. operators in the 8514 address localpart. This opens opportunities for obscure mail relay 8515 attacks with user@domain@domain addresses when Postfix provides 8516 backup MX service for Sendmail systems. </p> 8517 8518 8519 </DD> 8520 8521 <DT><b><a name="resolve_null_domain">resolve_null_domain</a> 8522 (default: no)</b></DT><DD> 8523 8524 <p> Resolve an address that ends in the "@" null domain as if the 8525 local hostname were specified, instead of rejecting the address as 8526 invalid. </p> 8527 8528 <p> This feature is available in Postfix 2.1 and later. 8529 Earlier versions always resolve the null domain as the local 8530 hostname. </p> 8531 8532 <p> The Postfix SMTP server uses this feature to reject mail from 8533 or to addresses that end in the "@" null domain, and from addresses 8534 that rewrite into a form that ends in the "@" null domain. </p> 8535 8536 8537 </DD> 8538 8539 <DT><b><a name="resolve_numeric_domain">resolve_numeric_domain</a> 8540 (default: no)</b></DT><DD> 8541 8542 <p> Resolve "user@ipaddress" as "user@[ipaddress]", instead of 8543 rejecting the address as invalid. </p> 8544 8545 <p> This feature is available in Postfix 2.3 and later. 8546 8547 8548 </DD> 8549 8550 <DT><b><a name="rewrite_service_name">rewrite_service_name</a> 8551 (default: rewrite)</b></DT><DD> 8552 8553 <p> 8554 The name of the address rewriting service. This service rewrites 8555 addresses to standard form and resolves them to a (delivery method, 8556 next-hop host, recipient) triple. 8557 </p> 8558 8559 <p> 8560 This feature is available in Postfix 2.0 and later. 8561 </p> 8562 8563 8564 </DD> 8565 8566 <DT><b><a name="sample_directory">sample_directory</a> 8567 (default: /etc/postfix)</b></DT><DD> 8568 8569 <p> 8570 The name of the directory with example Postfix configuration files. 8571 Starting with Postfix 2.1, these files have been replaced with the 8572 <a href="postconf.5.html">postconf(5)</a> manual page. 8573 </p> 8574 8575 8576 </DD> 8577 8578 <DT><b><a name="send_cyrus_sasl_authzid">send_cyrus_sasl_authzid</a> 8579 (default: no)</b></DT><DD> 8580 8581 <p> When authenticating to a remote SMTP or LMTP server with the 8582 default setting "no", send no SASL authoriZation ID (authzid); send 8583 only the SASL authentiCation ID (authcid) plus the authcid's password. 8584 </p> 8585 8586 <p> The non-default setting "yes" enables the behavior of older 8587 Postfix versions. These always send a SASL authzid that is equal 8588 to the SASL authcid, but this causes inter-operability problems 8589 with some SMTP servers. </p> 8590 8591 <p> This feature is available in Postfix 2.4.4 and later. </p> 8592 8593 8594 </DD> 8595 8596 <DT><b><a name="sender_based_routing">sender_based_routing</a> 8597 (default: no)</b></DT><DD> 8598 8599 <p> 8600 This parameter should not be used. It was replaced by <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> 8601 in Postfix version 2.3. 8602 </p> 8603 8604 8605 </DD> 8606 8607 <DT><b><a name="sender_bcc_maps">sender_bcc_maps</a> 8608 (default: empty)</b></DT><DD> 8609 8610 <p> Optional BCC (blind carbon-copy) address lookup tables, indexed 8611 by sender address. The BCC address (multiple results are not 8612 supported) is added when mail enters from outside of Postfix. </p> 8613 8614 <p> 8615 This feature is available in Postfix 2.1 and later. 8616 </p> 8617 8618 <p> 8619 The table search order is as follows: 8620 </p> 8621 8622 <ul> 8623 8624 <li> Look up the "user+extension (a] domain.tld" address including the 8625 optional address extension. 8626 8627 <li> Look up the "user (a] domain.tld" address without the optional 8628 address extension. 8629 8630 <li> Look up the "user+extension" address local part when the 8631 sender domain equals $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> 8632 or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. 8633 8634 <li> Look up the "user" address local part when the sender domain 8635 equals $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. 8636 8637 <li> Look up the "@domain.tld" part. 8638 8639 </ul> 8640 8641 <p> 8642 Specify the types and names of databases to use. After change, 8643 run "<b>postmap /etc/postfix/sender_bcc</b>". 8644 </p> 8645 8646 <p> 8647 Note: if mail to the BCC address bounces it will be returned to 8648 the sender. 8649 </p> 8650 8651 <p> Note: automatic BCC recipients are produced only for new mail. 8652 To avoid mailer loops, automatic BCC recipients are not generated 8653 after Postfix forwards mail internally, or after Postfix generates 8654 mail itself. </p> 8655 8656 <p> 8657 Example: 8658 </p> 8659 8660 <pre> 8661 <a href="postconf.5.html#sender_bcc_maps">sender_bcc_maps</a> = hash:/etc/postfix/sender_bcc 8662 </pre> 8663 8664 8665 </DD> 8666 8667 <DT><b><a name="sender_canonical_classes">sender_canonical_classes</a> 8668 (default: envelope_sender, header_sender)</b></DT><DD> 8669 8670 <p> What addresses are subject to <a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> address 8671 mapping. By default, <a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> address mapping is 8672 applied to envelope sender addresses, and to header sender addresses. 8673 </p> 8674 8675 <p> Specify one or more of: envelope_sender, header_sender </p> 8676 8677 <p> This feature is available in Postfix 2.2 and later. </p> 8678 8679 8680 </DD> 8681 8682 <DT><b><a name="sender_canonical_maps">sender_canonical_maps</a> 8683 (default: empty)</b></DT><DD> 8684 8685 <p> 8686 Optional address mapping lookup tables for envelope and header 8687 sender addresses. 8688 The table format and lookups are documented in <a href="canonical.5.html">canonical(5)</a>. 8689 </p> 8690 8691 <p> 8692 Example: you want to rewrite the SENDER address "user (a] ugly.domain" 8693 to "user (a] pretty.domain", while still being able to send mail to 8694 the RECIPIENT address "user (a] ugly.domain". 8695 </p> 8696 8697 <p> 8698 Note: $<a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> is processed before $<a href="postconf.5.html#canonical_maps">canonical_maps</a>. 8699 </p> 8700 8701 <p> 8702 Example: 8703 </p> 8704 8705 <pre> 8706 <a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> = hash:/etc/postfix/sender_canonical 8707 </pre> 8708 8709 8710 </DD> 8711 8712 <DT><b><a name="sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a> 8713 (default: empty)</b></DT><DD> 8714 8715 <p> A sender-dependent override for the global <a href="postconf.5.html#default_transport">default_transport</a> 8716 parameter setting. The tables are searched by the envelope sender 8717 address and @domain. A lookup result of DUNNO terminates the search 8718 without overriding the global <a href="postconf.5.html#default_transport">default_transport</a> parameter setting. 8719 This information is overruled with the <a href="transport.5.html">transport(5)</a> table. </p> 8720 8721 <p> Note: this overrides <a href="postconf.5.html#default_transport">default_transport</a>, not <a href="postconf.5.html#transport_maps">transport_maps</a>, and 8722 therefore the expected syntax is that of <a href="postconf.5.html#default_transport">default_transport</a>, not the 8723 syntax of <a href="postconf.5.html#transport_maps">transport_maps</a>. Specifically, this does not support the 8724 <a href="postconf.5.html#transport_maps">transport_maps</a> syntax for null transport, null nexthop, or null 8725 email addresses. </p> 8726 8727 <p> For safety reasons, this feature does not allow $number 8728 substitutions in regular expression maps. </p> 8729 8730 <p> This feature is available in Postfix 2.7 and later. </p> 8731 8732 8733 </DD> 8734 8735 <DT><b><a name="sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> 8736 (default: empty)</b></DT><DD> 8737 8738 <p> A sender-dependent override for the global <a href="postconf.5.html#relayhost">relayhost</a> parameter 8739 setting. The tables are searched by the envelope sender address and 8740 @domain. A lookup result of DUNNO terminates the search without 8741 overriding the global <a href="postconf.5.html#relayhost">relayhost</a> parameter setting (Postfix 2.6 and 8742 later). This information is overruled with <a href="postconf.5.html#relay_transport">relay_transport</a>, 8743 <a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a>, <a href="postconf.5.html#default_transport">default_transport</a> and with 8744 the <a href="transport.5.html">transport(5)</a> table. </p> 8745 8746 <p> For safety reasons, this feature does not allow $number 8747 substitutions in regular expression maps. </p> 8748 8749 <p> 8750 This feature is available in Postfix 2.3 and later. 8751 </p> 8752 8753 8754 </DD> 8755 8756 <DT><b><a name="sendmail_path">sendmail_path</a> 8757 (default: see "postconf -d" output)</b></DT><DD> 8758 8759 <p> 8760 A Sendmail compatibility feature that specifies the location of 8761 the Postfix <a href="sendmail.1.html">sendmail(1)</a> command. This command can be used to 8762 submit mail into the Postfix queue. 8763 </p> 8764 8765 8766 </DD> 8767 8768 <DT><b><a name="service_throttle_time">service_throttle_time</a> 8769 (default: 60s)</b></DT><DD> 8770 8771 <p> 8772 How long the Postfix <a href="master.8.html">master(8)</a> waits before forking a server that 8773 appears to be malfunctioning. 8774 </p> 8775 8776 <p> 8777 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 8778 The default time unit is s (seconds). 8779 </p> 8780 8781 8782 </DD> 8783 8784 <DT><b><a name="setgid_group">setgid_group</a> 8785 (default: postdrop)</b></DT><DD> 8786 8787 <p> 8788 The group ownership of set-gid Postfix commands and of group-writable 8789 Postfix directories. When this parameter value is changed you need 8790 to re-run "<b>postfix set-permissions</b>" (with Postfix version 2.0 and 8791 earlier: "<b>/etc/postfix/post-install set-permissions</b>". 8792 </p> 8793 8794 8795 </DD> 8796 8797 <DT><b><a name="show_user_unknown_table_name">show_user_unknown_table_name</a> 8798 (default: yes)</b></DT><DD> 8799 8800 <p> 8801 Display the name of the recipient table in the "User unknown" 8802 responses. The extra detail makes trouble shooting easier but also 8803 reveals information that is nobody elses business. 8804 </p> 8805 8806 <p> 8807 This feature is available in Postfix 2.0 and later. 8808 </p> 8809 8810 8811 </DD> 8812 8813 <DT><b><a name="showq_service_name">showq_service_name</a> 8814 (default: showq)</b></DT><DD> 8815 8816 <p> 8817 The name of the <a href="showq.8.html">showq(8)</a> service. This service produces mail queue 8818 status reports. 8819 </p> 8820 8821 <p> 8822 This feature is available in Postfix 2.0 and later. 8823 </p> 8824 8825 8826 </DD> 8827 8828 <DT><b><a name="smtp_address_preference">smtp_address_preference</a> 8829 (default: ipv6)</b></DT><DD> 8830 8831 <p> The address type ("ipv6", "ipv4" or "any") that the Postfix 8832 SMTP client will try first, when a destination has IPv6 and IPv4 8833 addresses with equal MX preference. This feature has no effect 8834 unless the <a href="postconf.5.html#inet_protocols">inet_protocols</a> setting enables both IPv4 and IPv6. </p> 8835 8836 <p> This feature is available in Postfix 2.8 and later. </p> 8837 8838 8839 </DD> 8840 8841 <DT><b><a name="smtp_always_send_ehlo">smtp_always_send_ehlo</a> 8842 (default: yes)</b></DT><DD> 8843 8844 <p> 8845 Always send EHLO at the start of an SMTP session. 8846 </p> 8847 8848 <p> 8849 With "<a href="postconf.5.html#smtp_always_send_ehlo">smtp_always_send_ehlo</a> = no", Postfix sends EHLO only when 8850 the word "ESMTP" appears in the server greeting banner (example: 8851 220 spike.porcupine.org ESMTP Postfix). 8852 </p> 8853 8854 8855 </DD> 8856 8857 <DT><b><a name="smtp_bind_address">smtp_bind_address</a> 8858 (default: empty)</b></DT><DD> 8859 8860 <p> 8861 An optional numerical network address that the Postfix SMTP client 8862 should bind to when making an IPv4 connection. 8863 </p> 8864 8865 <p> 8866 This can be specified in the <a href="postconf.5.html">main.cf</a> file for all SMTP clients, or 8867 it can be specified in the <a href="master.5.html">master.cf</a> file for a specific client, 8868 for example: 8869 </p> 8870 8871 <blockquote> 8872 <pre> 8873 /etc/postfix/<a href="master.5.html">master.cf</a>: 8874 smtp ... smtp -o <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a>=11.22.33.44 8875 </pre> 8876 </blockquote> 8877 8878 <p> Note 1: when <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> specifies no more than one IPv4 8879 address, and that address is a non-loopback address, it is 8880 automatically used as the <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a>. This supports virtual 8881 IP hosting, but can be a problem on multi-homed firewalls. See the 8882 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> documentation for more detail. </p> 8883 8884 <p> Note 2: address information may be enclosed inside <tt>[]</tt>, 8885 but this form is not required here. </p> 8886 8887 8888 </DD> 8889 8890 <DT><b><a name="smtp_bind_address6">smtp_bind_address6</a> 8891 (default: empty)</b></DT><DD> 8892 8893 <p> 8894 An optional numerical network address that the Postfix SMTP client 8895 should bind to when making an IPv6 connection. 8896 </p> 8897 8898 <p> This feature is available in Postfix 2.2 and later. </p> 8899 8900 <p> 8901 This can be specified in the <a href="postconf.5.html">main.cf</a> file for all SMTP clients, or 8902 it can be specified in the <a href="master.5.html">master.cf</a> file for a specific client, 8903 for example: 8904 </p> 8905 8906 <blockquote> 8907 <pre> 8908 /etc/postfix/<a href="master.5.html">master.cf</a>: 8909 smtp ... smtp -o <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a>=1:2:3:4:5:6:7:8 8910 </pre> 8911 </blockquote> 8912 8913 <p> Note 1: when <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> specifies no more than one IPv6 8914 address, and that address is a non-loopback address, it is 8915 automatically used as the <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a>. This supports virtual 8916 IP hosting, but can be a problem on multi-homed firewalls. See the 8917 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> documentation for more detail. </p> 8918 8919 <p> Note 2: address information may be enclosed inside <tt>[]</tt>, 8920 but this form is not recommended here. </p> 8921 8922 8923 </DD> 8924 8925 <DT><b><a name="smtp_body_checks">smtp_body_checks</a> 8926 (default: empty)</b></DT><DD> 8927 8928 <p> Restricted <a href="header_checks.5.html">body_checks(5)</a> tables for the Postfix SMTP client. 8929 These tables are searched while mail is being delivered. Actions 8930 that change the delivery time or destination are not available. 8931 </p> 8932 8933 <p> This feature is available in Postfix 2.5 and later. </p> 8934 8935 8936 </DD> 8937 8938 <DT><b><a name="smtp_cname_overrides_servername">smtp_cname_overrides_servername</a> 8939 (default: version dependent)</b></DT><DD> 8940 8941 <p> Allow DNS CNAME records to override the servername that the 8942 Postfix SMTP client uses for logging, SASL password lookup, TLS 8943 policy decisions, or TLS certificate verification. The value "no" 8944 hardens Postfix <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> hostname-based policies against 8945 false hostname information in DNS CNAME records, and makes SASL 8946 password file lookups more predictable. This is the default setting 8947 as of Postfix 2.3. </p> 8948 8949 <p> This feature is available in Postfix 2.2.9 and later. </p> 8950 8951 8952 </DD> 8953 8954 <DT><b><a name="smtp_connect_timeout">smtp_connect_timeout</a> 8955 (default: 30s)</b></DT><DD> 8956 8957 <p> 8958 The SMTP client time limit for completing a TCP connection, or 8959 zero (use the operating system built-in time limit). 8960 </p> 8961 8962 <p> 8963 When no connection can be made within the deadline, the Postfix 8964 SMTP client 8965 tries the next address on the mail exchanger list. Specify 0 to 8966 disable the time limit (i.e. use whatever timeout is implemented by 8967 the operating system). 8968 </p> 8969 8970 <p> 8971 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 8972 The default time unit is s (seconds). 8973 </p> 8974 8975 8976 </DD> 8977 8978 <DT><b><a name="smtp_connection_cache_destinations">smtp_connection_cache_destinations</a> 8979 (default: empty)</b></DT><DD> 8980 8981 <p> Permanently enable SMTP connection caching for the specified 8982 destinations. With SMTP connection caching, a connection is not 8983 closed immediately after completion of a mail transaction. Instead, 8984 the connection is kept open for up to $<a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> 8985 seconds. This allows connections to be reused for other deliveries, 8986 and can improve mail delivery performance. </p> 8987 8988 <p> Specify a comma or white space separated list of destinations 8989 or pseudo-destinations: </p> 8990 8991 <ul> 8992 8993 <li> if mail is sent without a <a href="postconf.5.html#relayhost">relay host</a>: a domain name (the 8994 right-hand side of an email address, without the [] around a numeric 8995 IP address), 8996 8997 <li> if mail is sent via a <a href="postconf.5.html#relayhost">relay host</a>: a <a href="postconf.5.html#relayhost">relay host</a> name (without 8998 [] or non-default TCP port), as specified in <a href="postconf.5.html">main.cf</a> or in the 8999 transport map, 9000 9001 <li> if mail is sent via a UNIX-domain socket: a pathname (without 9002 the unix: prefix), 9003 9004 <li> a /file/name with domain names and/or <a href="postconf.5.html#relayhost">relay host</a> names as 9005 defined above, 9006 9007 <li> a "<a href="DATABASE_README.html">type:table</a>" with domain names and/or <a href="postconf.5.html#relayhost">relay host</a> names on 9008 the left-hand side. The right-hand side result from "<a href="DATABASE_README.html">type:table</a>" 9009 lookups is ignored. 9010 9011 </ul> 9012 9013 <p> This feature is available in Postfix 2.2 and later. </p> 9014 9015 9016 </DD> 9017 9018 <DT><b><a name="smtp_connection_cache_on_demand">smtp_connection_cache_on_demand</a> 9019 (default: yes)</b></DT><DD> 9020 9021 <p> Temporarily enable SMTP connection caching while a destination 9022 has a high volume of mail in the <a href="QSHAPE_README.html#active_queue">active queue</a>. With SMTP connection 9023 caching, a connection is not closed immediately after completion 9024 of a mail transaction. Instead, the connection is kept open for 9025 up to $<a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> seconds. This allows 9026 connections to be reused for other deliveries, and can improve mail 9027 delivery performance. </p> 9028 9029 <p> This feature is available in Postfix 2.2 and later. </p> 9030 9031 9032 </DD> 9033 9034 <DT><b><a name="smtp_connection_cache_reuse_limit">smtp_connection_cache_reuse_limit</a> 9035 (default: 10)</b></DT><DD> 9036 9037 <p> When SMTP connection caching is enabled, the number of times that 9038 an SMTP session may be reused before it is closed. 9039 </p> 9040 9041 <p> This feature is available in Postfix 2.2. In Postfix 2.3 it is 9042 replaced by $<a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a>.</p> 9043 9044 9045 </DD> 9046 9047 <DT><b><a name="smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> 9048 (default: 2s)</b></DT><DD> 9049 9050 <p> When SMTP connection caching is enabled, the amount of time that 9051 an unused SMTP client socket is kept open before it is closed. Do 9052 not specify larger values without permission from the remote sites. 9053 </p> 9054 9055 <p> This feature is available in Postfix 2.2 and later. </p> 9056 9057 9058 </DD> 9059 9060 <DT><b><a name="smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a> 9061 (default: 300s)</b></DT><DD> 9062 9063 <p> The amount of time during which Postfix will use an SMTP 9064 connection repeatedly. The timer starts when the connection is 9065 initiated (i.e. it includes the connect, greeting and helo latency, 9066 in addition to the latencies of subsequent mail delivery transactions). 9067 </p> 9068 9069 <p> This feature addresses a performance stability problem with 9070 remote SMTP servers. This problem is not specific to Postfix: it 9071 can happen when any MTA sends large amounts of SMTP email to a site 9072 that has multiple MX hosts. </p> 9073 9074 <p> The problem starts when one of a set of MX hosts becomes slower 9075 than the rest. Even though SMTP clients connect to fast and slow 9076 MX hosts with equal probability, the slow MX host ends up with more 9077 simultaneous inbound connections than the faster MX hosts, because 9078 the slow MX host needs more time to serve each client request. </p> 9079 9080 <p> The slow MX host becomes a connection attractor. If one MX 9081 host becomes N times slower than the rest, it dominates mail delivery 9082 latency unless there are more than N fast MX hosts to counter the 9083 effect. And if the number of MX hosts is smaller than N, the mail 9084 delivery latency becomes effectively that of the slowest MX host 9085 divided by the total number of MX hosts. </p> 9086 9087 <p> The solution uses connection caching in a way that differs from 9088 Postfix version 2.2. By limiting the amount of time during which a connection 9089 can be used repeatedly (instead of limiting the number of deliveries 9090 over that connection), Postfix not only restores fairness in the 9091 distribution of simultaneous connections across a set of MX hosts, 9092 it also favors deliveries over connections that perform well, which 9093 is exactly what we want. </p> 9094 9095 <p> The default reuse time limit, 300s, is comparable to the various 9096 smtp transaction timeouts which are fair estimates of maximum excess 9097 latency for a slow delivery. Note that hosts may accept thousands 9098 of messages over a single connection within the default connection 9099 reuse time limit. This number is much larger than the default Postfix 9100 version 2.2 limit of 10 messages per cached connection. It may prove necessary 9101 to lower the limit to avoid interoperability issues with MTAs that 9102 exhibit bugs when many messages are delivered via a single connection. 9103 A lower reuse time limit risks losing the benefit of connection 9104 reuse when the average connection and mail delivery latency exceeds 9105 the reuse time limit. </p> 9106 9107 <p> This feature is available in Postfix 2.3 and later. </p> 9108 9109 9110 </DD> 9111 9112 <DT><b><a name="smtp_data_done_timeout">smtp_data_done_timeout</a> 9113 (default: 600s)</b></DT><DD> 9114 9115 <p> 9116 The SMTP client time limit for sending the SMTP ".", and for receiving 9117 the server response. 9118 </p> 9119 9120 <p> 9121 When no response is received within the deadline, a warning is 9122 logged that the mail may be delivered multiple times. 9123 </p> 9124 9125 <p> 9126 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 9127 The default time unit is s (seconds). 9128 </p> 9129 9130 9131 </DD> 9132 9133 <DT><b><a name="smtp_data_init_timeout">smtp_data_init_timeout</a> 9134 (default: 120s)</b></DT><DD> 9135 9136 <p> 9137 The SMTP client time limit for sending the SMTP DATA command, and for 9138 receiving the server response. 9139 </p> 9140 9141 <p> 9142 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 9143 The default time unit is s (seconds). 9144 </p> 9145 9146 9147 </DD> 9148 9149 <DT><b><a name="smtp_data_xfer_timeout">smtp_data_xfer_timeout</a> 9150 (default: 180s)</b></DT><DD> 9151 9152 <p> 9153 The SMTP client time limit for sending the SMTP message content. 9154 When the connection makes no progress for more than $<a href="postconf.5.html#smtp_data_xfer_timeout">smtp_data_xfer_timeout</a> 9155 seconds the Postfix SMTP client terminates the transfer. 9156 </p> 9157 9158 <p> 9159 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 9160 The default time unit is s (seconds). 9161 </p> 9162 9163 9164 </DD> 9165 9166 <DT><b><a name="smtp_defer_if_no_mx_address_found">smtp_defer_if_no_mx_address_found</a> 9167 (default: no)</b></DT><DD> 9168 9169 <p> 9170 Defer mail delivery when no MX record resolves to an IP address. 9171 </p> 9172 9173 <p> 9174 The default (no) is to return the mail as undeliverable. With older 9175 Postfix versions the default was to keep trying to deliver the mail 9176 until someone fixed the MX record or until the mail was too old. 9177 </p> 9178 9179 <p> 9180 Note: Postfix always ignores MX records with equal or worse preference 9181 than the local MTA itself. 9182 </p> 9183 9184 <p> 9185 This feature is available in Postfix 2.1 and later. 9186 </p> 9187 9188 9189 </DD> 9190 9191 <DT><b><a name="smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a> 9192 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 9193 9194 <p> The maximal number of parallel deliveries to the same destination 9195 via the smtp message delivery transport. This limit is enforced by 9196 the queue manager. The message delivery transport name is the first 9197 field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 9198 9199 9200 </DD> 9201 9202 <DT><b><a name="smtp_destination_recipient_limit">smtp_destination_recipient_limit</a> 9203 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 9204 9205 <p> The maximal number of recipients per message for the smtp 9206 message delivery transport. This limit is enforced by the queue 9207 manager. The message delivery transport name is the first field in 9208 the entry in the <a href="master.5.html">master.cf</a> file. </p> 9209 9210 <p> Setting this parameter to a value of 1 changes the meaning of 9211 <a href="postconf.5.html#smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a> from concurrency per domain 9212 into concurrency per recipient. </p> 9213 9214 9215 </DD> 9216 9217 <DT><b><a name="smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a> 9218 (default: empty)</b></DT><DD> 9219 9220 <p> Lookup tables, indexed by the remote SMTP server address, with 9221 case insensitive lists of EHLO keywords (pipelining, starttls, auth, 9222 etc.) that the Postfix SMTP client will ignore in the EHLO response from a 9223 remote SMTP server. See <a href="postconf.5.html#smtp_discard_ehlo_keywords">smtp_discard_ehlo_keywords</a> for details. The 9224 table is not indexed by hostname for consistency with 9225 <a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a>. </p> 9226 9227 <p> This feature is available in Postfix 2.2 and later. </p> 9228 9229 9230 </DD> 9231 9232 <DT><b><a name="smtp_discard_ehlo_keywords">smtp_discard_ehlo_keywords</a> 9233 (default: empty)</b></DT><DD> 9234 9235 <p> A case insensitive list of EHLO keywords (pipelining, starttls, 9236 auth, etc.) that the Postfix SMTP client will ignore in the EHLO 9237 response from a remote SMTP server. </p> 9238 9239 <p> This feature is available in Postfix 2.2 and later. </p> 9240 9241 <p> Notes: </p> 9242 9243 <ul> 9244 9245 <li> <p> Specify the <b>silent-discard</b> pseudo keyword to prevent 9246 this action from being logged. </p> 9247 9248 <li> <p> Use the <a href="postconf.5.html#smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a> feature to 9249 discard EHLO keywords selectively. </p> 9250 9251 </ul> 9252 9253 9254 </DD> 9255 9256 <DT><b><a name="smtp_dns_resolver_options">smtp_dns_resolver_options</a> 9257 (default: empty)</b></DT><DD> 9258 9259 <p> DNS Resolver options for the Postfix SMTP client. Specify zero 9260 or more of the following options, separated by comma or whitespace. 9261 Option names are case-sensitive. Some options refer to domain names 9262 that are specified in the file /etc/resolv.conf or equivalent. </p> 9263 9264 <dl> 9265 9266 <dt><b>res_defnames</b></dt> 9267 9268 <dd> Append the current domain name to single-component names (those 9269 that do not contain a "." character). This can produce incorrect 9270 results, and is the hard-coded behavior prior to Postfix 2.8. </dd> 9271 9272 <dt><b>res_dnsrch</b></dt> 9273 9274 <dd> Search for host names in the current domain and in parent 9275 domains. This can produce incorrect results and is therefore not 9276 recommended. </dd> 9277 9278 </dl> 9279 9280 <p> This feature is available in Postfix 2.8 and later. </p> 9281 9282 9283 </DD> 9284 9285 <DT><b><a name="smtp_enforce_tls">smtp_enforce_tls</a> 9286 (default: no)</b></DT><DD> 9287 9288 <p> Enforcement mode: require that remote SMTP servers use TLS 9289 encryption, and never send mail in the clear. This also requires 9290 that the remote SMTP server hostname matches the information in 9291 the remote server certificate, and that the remote SMTP server 9292 certificate was issued by a CA that is trusted by the Postfix SMTP 9293 client. If the certificate doesn't verify or the hostname doesn't 9294 match, delivery is deferred and mail stays in the queue. </p> 9295 9296 <p> The server hostname is matched against all names provided as 9297 dNSNames in the SubjectAlternativeName. If no dNSNames are specified, 9298 the CommonName is checked. The behavior may be changed with the 9299 <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> option. </p> 9300 9301 <p> This option is useful only if you are definitely sure that you 9302 will only connect to servers that support <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> _and_ that 9303 provide valid server certificates. Typical use is for clients that 9304 send all their email to a dedicated mailhub. </p> 9305 9306 <p> This feature is available in Postfix 2.2 and later. With 9307 Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> instead. </p> 9308 9309 9310 </DD> 9311 9312 <DT><b><a name="smtp_fallback_relay">smtp_fallback_relay</a> 9313 (default: $<a href="postconf.5.html#fallback_relay">fallback_relay</a>)</b></DT><DD> 9314 9315 <p> 9316 Optional list of relay hosts for SMTP destinations that can't be 9317 found or that are unreachable. With Postfix 2.2 and earlier this 9318 parameter is called <a href="postconf.5.html#fallback_relay">fallback_relay</a>. </p> 9319 9320 <p> 9321 By default, mail is returned to the sender when a destination is 9322 not found, and delivery is deferred when a destination is unreachable. 9323 </p> 9324 9325 <p> The fallback relays must be SMTP destinations. Specify a domain, 9326 host, host:port, [host]:port, [address] or [address]:port; the form 9327 [host] turns off MX lookups. If you specify multiple SMTP 9328 destinations, Postfix will try them in the specified order. </p> 9329 9330 <p> To prevent mailer loops between MX hosts and fall-back hosts, 9331 Postfix version 2.2 and later will not use the fallback relays for 9332 destinations that it is MX host for (assuming DNS lookup is turned on). 9333 </p> 9334 9335 9336 </DD> 9337 9338 <DT><b><a name="smtp_generic_maps">smtp_generic_maps</a> 9339 (default: empty)</b></DT><DD> 9340 9341 <p> Optional lookup tables that perform address rewriting in the 9342 SMTP client, typically to transform a locally valid address into 9343 a globally valid address when sending mail across the Internet. 9344 This is needed when the local machine does not have its own Internet 9345 domain name, but uses something like <i>localdomain.local</i> 9346 instead. </p> 9347 9348 <p> The table format and lookups are documented in <a href="generic.5.html">generic(5)</a>; 9349 examples are shown in the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> and 9350 <a href="STANDARD_CONFIGURATION_README.html">STANDARD_CONFIGURATION_README</a> documents. </p> 9351 9352 <p> This feature is available in Postfix 2.2 and later. </p> 9353 9354 9355 </DD> 9356 9357 <DT><b><a name="smtp_header_checks">smtp_header_checks</a> 9358 (default: empty)</b></DT><DD> 9359 9360 <p> Restricted <a href="header_checks.5.html">header_checks(5)</a> tables for the Postfix SMTP client. 9361 These tables are searched while mail is being delivered. Actions 9362 that change the delivery time or destination are not available. 9363 </p> 9364 9365 <p> This feature is available in Postfix 2.5 and later. </p> 9366 9367 9368 </DD> 9369 9370 <DT><b><a name="smtp_helo_name">smtp_helo_name</a> 9371 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 9372 9373 <p> 9374 The hostname to send in the SMTP EHLO or HELO command. 9375 </p> 9376 9377 <p> 9378 The default value is the machine hostname. Specify a hostname or 9379 [ip.add.re.ss]. 9380 </p> 9381 9382 <p> 9383 This information can be specified in the <a href="postconf.5.html">main.cf</a> file for all SMTP 9384 clients, or it can be specified in the <a href="master.5.html">master.cf</a> file for a specific 9385 client, for example: 9386 </p> 9387 9388 <blockquote> 9389 <pre> 9390 /etc/postfix/<a href="master.5.html">master.cf</a>: 9391 mysmtp ... smtp -o <a href="postconf.5.html#smtp_helo_name">smtp_helo_name</a>=foo.bar.com 9392 </pre> 9393 </blockquote> 9394 9395 <p> 9396 This feature is available in Postfix 2.0 and later. 9397 </p> 9398 9399 9400 </DD> 9401 9402 <DT><b><a name="smtp_helo_timeout">smtp_helo_timeout</a> 9403 (default: 300s)</b></DT><DD> 9404 9405 <p> 9406 The SMTP client time limit for sending the HELO or EHLO command, 9407 and for receiving the initial server response. 9408 </p> 9409 9410 <p> 9411 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 9412 The default time unit is s (seconds). 9413 </p> 9414 9415 9416 </DD> 9417 9418 <DT><b><a name="smtp_host_lookup">smtp_host_lookup</a> 9419 (default: dns)</b></DT><DD> 9420 9421 <p> 9422 What mechanisms the Postfix SMTP client uses to look up a host's IP 9423 address. This parameter is ignored when DNS lookups are disabled 9424 (see: <a href="postconf.5.html#disable_dns_lookups">disable_dns_lookups</a>). 9425 </p> 9426 9427 <p> 9428 Specify one of the following: 9429 </p> 9430 9431 <dl> 9432 9433 <dt><b>dns</b></dt> 9434 9435 <dd>Hosts can be found in the DNS (preferred). </dd> 9436 9437 <dt><b>native</b></dt> 9438 9439 <dd>Use the native naming service only (nsswitch.conf, or equivalent 9440 mechanism). </dd> 9441 9442 <dt><b>dns, native</b></dt> 9443 9444 <dd>Use the native service for hosts not found in the DNS. </dd> 9445 9446 </dl> 9447 9448 <p> 9449 This feature is available in Postfix 2.1 and later. 9450 </p> 9451 9452 9453 </DD> 9454 9455 <DT><b><a name="smtp_line_length_limit">smtp_line_length_limit</a> 9456 (default: 990)</b></DT><DD> 9457 9458 <p> 9459 The maximal length of message header and body lines that Postfix 9460 will send via SMTP. Longer lines are broken by inserting 9461 "<CR><LF><SPACE>". This minimizes the damage to 9462 MIME formatted mail. 9463 </p> 9464 9465 <p> 9466 By default, the line length is limited to 990 characters, because 9467 some server implementations cannot receive mail with long lines. 9468 </p> 9469 9470 9471 </DD> 9472 9473 <DT><b><a name="smtp_mail_timeout">smtp_mail_timeout</a> 9474 (default: 300s)</b></DT><DD> 9475 9476 <p> 9477 The SMTP client time limit for sending the MAIL FROM command, and 9478 for receiving the server response. 9479 </p> 9480 9481 <p> 9482 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 9483 The default time unit is s (seconds). 9484 </p> 9485 9486 9487 </DD> 9488 9489 <DT><b><a name="smtp_mime_header_checks">smtp_mime_header_checks</a> 9490 (default: empty)</b></DT><DD> 9491 9492 <p> Restricted mime_<a href="header_checks.5.html">header_checks(5)</a> tables for the Postfix SMTP 9493 client. These tables are searched while mail is being delivered. 9494 Actions that change the delivery time or destination are not 9495 available. </p> 9496 9497 <p> This feature is available in Postfix 2.5 and later. </p> 9498 9499 9500 </DD> 9501 9502 <DT><b><a name="smtp_mx_address_limit">smtp_mx_address_limit</a> 9503 (default: 5)</b></DT><DD> 9504 9505 <p> 9506 The maximal number of MX (mail exchanger) IP addresses that can 9507 result from mail exchanger lookups, or zero (no limit). Prior to 9508 Postfix version 2.3, this limit was disabled by default. 9509 </p> 9510 9511 <p> 9512 This feature is available in Postfix 2.1 and later. 9513 </p> 9514 9515 9516 </DD> 9517 9518 <DT><b><a name="smtp_mx_session_limit">smtp_mx_session_limit</a> 9519 (default: 2)</b></DT><DD> 9520 9521 <p> The maximal number of SMTP sessions per delivery request before 9522 giving up or delivering to a fall-back <a href="postconf.5.html#relayhost">relay host</a>, or zero (no 9523 limit). This restriction ignores sessions that fail to complete the 9524 SMTP initial handshake (Postfix version 2.2 and earlier) or that fail to 9525 complete the EHLO and TLS handshake (Postfix version 2.3 and later). </p> 9526 9527 <p> This feature is available in Postfix 2.1 and later. </p> 9528 9529 9530 </DD> 9531 9532 <DT><b><a name="smtp_nested_header_checks">smtp_nested_header_checks</a> 9533 (default: empty)</b></DT><DD> 9534 9535 <p> Restricted nested_<a href="header_checks.5.html">header_checks(5)</a> tables for the Postfix SMTP 9536 client. These tables are searched while mail is being delivered. 9537 Actions that change the delivery time or destination are not 9538 available. </p> 9539 9540 <p> This feature is available in Postfix 2.5 and later. </p> 9541 9542 9543 </DD> 9544 9545 <DT><b><a name="smtp_never_send_ehlo">smtp_never_send_ehlo</a> 9546 (default: no)</b></DT><DD> 9547 9548 <p> Never send EHLO at the start of an SMTP session. See also the 9549 <a href="postconf.5.html#smtp_always_send_ehlo">smtp_always_send_ehlo</a> parameter. </p> 9550 9551 9552 </DD> 9553 9554 <DT><b><a name="smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a> 9555 (default: 10s)</b></DT><DD> 9556 9557 <p> 9558 How long the Postfix SMTP client pauses before sending 9559 ".<CR><LF>" in order to work around the PIX firewall 9560 "<CR><LF>.<CR><LF>" bug. 9561 </p> 9562 9563 <p> 9564 Choosing a too short time makes this workaround ineffective when 9565 sending large messages over slow network connections. 9566 </p> 9567 9568 9569 </DD> 9570 9571 <DT><b><a name="smtp_pix_workaround_maps">smtp_pix_workaround_maps</a> 9572 (default: empty)</b></DT><DD> 9573 9574 <p> Lookup tables, indexed by the remote SMTP server address, with 9575 per-destination workarounds for CISCO PIX firewall bugs. The table 9576 is not indexed by hostname for consistency with 9577 <a href="postconf.5.html#smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a>. </p> 9578 9579 <p> This feature is available in Postfix 2.4 and later. </p> 9580 9581 9582 </DD> 9583 9584 <DT><b><a name="smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a> 9585 (default: 500s)</b></DT><DD> 9586 9587 <p> How long a message must be queued before the Postfix SMTP client 9588 turns on the PIX firewall "<CR><LF>.<CR><LF>" 9589 bug workaround for delivery through firewalls with "smtp fixup" 9590 mode turned on. </p> 9591 9592 <p> 9593 By default, the workaround is turned off for mail that is queued 9594 for less than 500 seconds. In other words, the workaround is normally 9595 turned off for the first delivery attempt. 9596 </p> 9597 9598 <p> 9599 Specify 0 to enable the PIX firewall 9600 "<CR><LF>.<CR><LF>" bug workaround upon the 9601 first delivery attempt. 9602 </p> 9603 9604 9605 </DD> 9606 9607 <DT><b><a name="smtp_pix_workarounds">smtp_pix_workarounds</a> 9608 (default: disable_esmtp, delay_dotcrlf)</b></DT><DD> 9609 9610 <p> A list that specifies zero or more workarounds for CISCO PIX 9611 firewall bugs. These workarounds are implemented by the Postfix 9612 SMTP client. Workaround names are separated by comma or space, and 9613 are case insensitive. This parameter setting can be overruled with 9614 per-destination <a href="postconf.5.html#smtp_pix_workaround_maps">smtp_pix_workaround_maps</a> settings. </p> 9615 9616 <dl> 9617 9618 <dt><b>delay_dotcrlf</b><dd> Insert a delay before sending 9619 ".<CR><LF>" after the end of the message content. The 9620 delay is subject to the <a href="postconf.5.html#smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a> and 9621 <a href="postconf.5.html#smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a> parameter settings. </dd> 9622 9623 <dt><b>disable_esmtp</b><dd> Disable all extended SMTP commands: 9624 send HELO instead of EHLO. </dd> 9625 9626 </dl> 9627 9628 <p> This feature is available in Postfix 2.4 and later. The default 9629 settings are backwards compatible with earlier Postfix versions. 9630 </p> 9631 9632 9633 </DD> 9634 9635 <DT><b><a name="smtp_quit_timeout">smtp_quit_timeout</a> 9636 (default: 300s)</b></DT><DD> 9637 9638 <p> 9639 The SMTP client time limit for sending the QUIT command, and for 9640 receiving the server response. 9641 </p> 9642 9643 <p> 9644 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 9645 The default time unit is s (seconds). 9646 </p> 9647 9648 9649 </DD> 9650 9651 <DT><b><a name="smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a> 9652 (default: yes)</b></DT><DD> 9653 9654 <p> 9655 Quote addresses in SMTP MAIL FROM and RCPT TO commands as required 9656 by <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. This includes putting quotes around an address localpart 9657 that ends in ".". 9658 </p> 9659 9660 <p> 9661 The default is to comply with <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. If you have to send mail to 9662 a broken SMTP server, configure a special SMTP client in <a href="master.5.html">master.cf</a>: 9663 </p> 9664 9665 <blockquote> 9666 <pre> 9667 /etc/postfix/<a href="master.5.html">master.cf</a>: 9668 broken-smtp . . . smtp -o <a href="postconf.5.html#smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a>=no 9669 </pre> 9670 </blockquote> 9671 9672 <p> 9673 and route mail for the destination in question to the "broken-smtp" 9674 message delivery with a <a href="transport.5.html">transport(5)</a> table. 9675 </p> 9676 9677 <p> 9678 This feature is available in Postfix 2.1 and later. 9679 </p> 9680 9681 9682 </DD> 9683 9684 <DT><b><a name="smtp_randomize_addresses">smtp_randomize_addresses</a> 9685 (default: yes)</b></DT><DD> 9686 9687 <p> 9688 Randomize the order of equal-preference MX host addresses. This 9689 is a performance feature of the Postfix SMTP client. 9690 </p> 9691 9692 9693 </DD> 9694 9695 <DT><b><a name="smtp_rcpt_timeout">smtp_rcpt_timeout</a> 9696 (default: 300s)</b></DT><DD> 9697 9698 <p> 9699 The SMTP client time limit for sending the SMTP RCPT TO command, and 9700 for receiving the server response. 9701 </p> 9702 9703 <p> 9704 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 9705 The default time unit is s (seconds). 9706 </p> 9707 9708 9709 </DD> 9710 9711 <DT><b><a name="smtp_reply_filter">smtp_reply_filter</a> 9712 (default: empty)</b></DT><DD> 9713 9714 <p> A mechanism to transform replies from remote SMTP servers one 9715 line at a time. This is a last-resort tool to work around server 9716 replies that break inter-operability with the Postfix SMTP client. 9717 Other uses involve fault injection to test Postfix's handling of 9718 invalid responses. </p> 9719 9720 <p> Notes: </p> 9721 9722 <ul> 9723 9724 <li> <p> In the case of a multi-line reply, the Postfix SMTP client 9725 uses the final reply line's numerical SMTP reply code and enhanced 9726 status code. </p> 9727 9728 <li> <p> The numerical SMTP reply code (XYZ) takes precedence over 9729 the enhanced status code (X.Y.Z). When the enhanced status code 9730 initial digit differs from the SMTP reply code initial digit, or 9731 when no enhanced status code is present, the Postfix SMTP client 9732 uses a generic enhanced status code (X.0.0) instead. </p> 9733 9734 </ul> 9735 9736 <p> Specify the name of a "<a href="DATABASE_README.html">type:table</a>" lookup table. The search 9737 string is a single SMTP reply line as received from the remote SMTP 9738 server, except that the trailing <CR><LF> are removed. </p> 9739 9740 <p> Examples: </p> 9741 9742 <pre> 9743 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 9744 <a href="postconf.5.html#smtp_reply_filter">smtp_reply_filter</a> = <a href="pcre_table.5.html">pcre</a>:/etc/postfix/reply_filter 9745 </pre> 9746 9747 <pre> 9748 /etc/postfix/reply_filter: 9749 # Transform garbage into "250-filler..." so that it looks like 9750 # one line from a multi-line reply. It does not matter what we 9751 # substitute here as long it has the right syntax. The Postfix 9752 # SMTP client will use the final line's numerical SMTP reply 9753 # code and enhanced status code. 9754 !/^([2-5][0-9][0-9]($|[- ]))/ 250-filler for garbage 9755 </pre> 9756 9757 <p> This feature is available in Postfix 2.7. </p> 9758 9759 9760 </DD> 9761 9762 <DT><b><a name="smtp_rset_timeout">smtp_rset_timeout</a> 9763 (default: 20s)</b></DT><DD> 9764 9765 <p> The SMTP client time limit for sending the RSET command, and 9766 for receiving the server response. The SMTP client sends RSET in 9767 order to finish a recipient address probe, or to verify that a 9768 cached session is still usable. </p> 9769 9770 <p> This feature is available in Postfix 2.1 and later. </p> 9771 9772 9773 </DD> 9774 9775 <DT><b><a name="smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> 9776 (default: empty)</b></DT><DD> 9777 9778 <p> An optional table to prevent repeated SASL authentication 9779 failures with the same remote SMTP server hostname, username and 9780 password. Each table (key, value) pair contains a server name, a 9781 username and password, and the full server response. This information 9782 is stored when a remote SMTP server rejects an authentication attempt 9783 with a 535 reply code. As long as the <a href="postconf.5.html#smtp_sasl_password_maps">smtp_sasl_password_maps</a> 9784 information does no change, and as long as the <a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> 9785 information does not expire (see <a href="postconf.5.html#smtp_sasl_auth_cache_time">smtp_sasl_auth_cache_time</a>) the 9786 Postfix SMTP client avoids SASL authentication attempts with the 9787 same server, username and password, and instead bounces or defers 9788 mail as controlled with the <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> configuration 9789 parameter. </p> 9790 9791 <p> Use a per-destination delivery concurrency of 1 (for example, 9792 "<a href="postconf.5.html#smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a> = 1", 9793 "<a href="postconf.5.html#relay_destination_concurrency_limit">relay_destination_concurrency_limit</a> = 1", etc.), otherwise multiple 9794 delivery agents may experience a login failure at the same time. 9795 </p> 9796 9797 <p> The table must be accessed via the proxywrite service, i.e. the 9798 map name must start with "<a href="proxymap.8.html">proxy</a>:". The table should be stored under 9799 the directory specified with the <a href="postconf.5.html#data_directory">data_directory</a> parameter. </p> 9800 9801 <p> This feature uses cryptographic hashing to protect plain-text 9802 passwords, and requires that Postfix is compiled with TLS support. 9803 </p> 9804 9805 <p> Example: </p> 9806 9807 <pre> 9808 <a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> = <a href="proxymap.8.html">proxy</a>:btree:/var/db/postfix/sasl_auth_cache 9809 </pre> 9810 9811 <p> This feature is available in Postfix 2.5 and later. </p> 9812 9813 9814 </DD> 9815 9816 <DT><b><a name="smtp_sasl_auth_cache_time">smtp_sasl_auth_cache_time</a> 9817 (default: 90d)</b></DT><DD> 9818 9819 <p> The maximal age of an <a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> entry before it 9820 is removed. </p> 9821 9822 <p> This feature is available in Postfix 2.5 and later. </p> 9823 9824 9825 </DD> 9826 9827 <DT><b><a name="smtp_sasl_auth_enable">smtp_sasl_auth_enable</a> 9828 (default: no)</b></DT><DD> 9829 9830 <p> 9831 Enable SASL authentication in the Postfix SMTP client. By default, 9832 the Postfix SMTP client uses no authentication. 9833 </p> 9834 9835 <p> 9836 Example: 9837 </p> 9838 9839 <pre> 9840 <a href="postconf.5.html#smtp_sasl_auth_enable">smtp_sasl_auth_enable</a> = yes 9841 </pre> 9842 9843 9844 </DD> 9845 9846 <DT><b><a name="smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> 9847 (default: yes)</b></DT><DD> 9848 9849 <p> When a remote SMTP server rejects a SASL authentication request 9850 with a 535 reply code, defer mail delivery instead of returning 9851 mail as undeliverable. The latter behavior was hard-coded prior to 9852 Postfix version 2.5. </p> 9853 9854 <p> Note: the setting "yes" overrides the global <a href="postconf.5.html#soft_bounce">soft_bounce</a> 9855 parameter, but the setting "no" does not. </p> 9856 9857 <p> Example: </p> 9858 9859 <pre> 9860 # Default as of Postfix 2.5 9861 <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> = yes 9862 # The old hard-coded default 9863 <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> = no 9864 </pre> 9865 9866 <p> This feature is available in Postfix 2.5 and later. </p> 9867 9868 9869 </DD> 9870 9871 <DT><b><a name="smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> 9872 (default: empty)</b></DT><DD> 9873 9874 <p> 9875 If non-empty, a Postfix SMTP client filter for the remote SMTP 9876 server's list of offered SASL mechanisms. Different client and 9877 server implementations may support different mechanism lists. By 9878 default, the Postfix SMTP client will use the intersection of the 9879 two. <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> further restricts what server 9880 mechanisms the client will take into consideration. </p> 9881 9882 <p> Specify mechanism names, "/file/name" patterns or "<a href="DATABASE_README.html">type:table</a>" 9883 lookup tables. The right-hand side result from "<a href="DATABASE_README.html">type:table</a>" lookups 9884 is ignored. Specify "!pattern" to exclude a mechanism name from the 9885 list. The form "!/file/name" is supported only in Postfix version 9886 2.4 and later. </p> 9887 9888 <p> This feature is available in Postfix 2.2 and later. </p> 9889 9890 <p> 9891 Examples: 9892 </p> 9893 9894 <pre> 9895 <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> = plain, login 9896 <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> = /etc/postfix/smtp_mechs 9897 <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> = !gssapi, !login, static:rest 9898 </pre> 9899 9900 9901 </DD> 9902 9903 <DT><b><a name="smtp_sasl_password_maps">smtp_sasl_password_maps</a> 9904 (default: empty)</b></DT><DD> 9905 9906 <p> 9907 Optional SMTP client lookup tables with one username:password entry 9908 per remote hostname or domain, or sender address when sender-dependent 9909 authentication is enabled. If no username:password entry is found, 9910 then the Postfix SMTP client will not 9911 attempt to authenticate to the remote host. 9912 </p> 9913 9914 <p> 9915 The Postfix SMTP client opens the lookup table before going to 9916 chroot jail, so you can leave the password file in /etc/postfix. 9917 </p> 9918 9919 9920 </DD> 9921 9922 <DT><b><a name="smtp_sasl_path">smtp_sasl_path</a> 9923 (default: empty)</b></DT><DD> 9924 9925 <p> Implementation-specific information that the Postfix SMTP client 9926 passes through to 9927 the SASL plug-in implementation that is selected with 9928 <b><a href="postconf.5.html#smtp_sasl_type">smtp_sasl_type</a></b>. Typically this specifies the name of a 9929 configuration file or rendezvous point. </p> 9930 9931 <p> This feature is available in Postfix 2.3 and later. </p> 9932 9933 9934 </DD> 9935 9936 <DT><b><a name="smtp_sasl_security_options">smtp_sasl_security_options</a> 9937 (default: noplaintext, noanonymous)</b></DT><DD> 9938 9939 <p> Postfix SMTP client SASL security options; as of Postfix 2.3 9940 the list of available 9941 features depends on the SASL client implementation that is selected 9942 with <b><a href="postconf.5.html#smtp_sasl_type">smtp_sasl_type</a></b>. </p> 9943 9944 <p> The following security features are defined for the <b>cyrus</b> 9945 client SASL implementation: </p> 9946 9947 <p> 9948 Specify zero or more of the following: 9949 </p> 9950 9951 <dl> 9952 9953 <dt><b>noplaintext</b></dt> 9954 9955 <dd>Disallow methods that use plaintext passwords. </dd> 9956 9957 <dt><b>noactive</b></dt> 9958 9959 <dd>Disallow methods subject to active (non-dictionary) attack. 9960 </dd> 9961 9962 <dt><b>nodictionary</b></dt> 9963 9964 <dd>Disallow methods subject to passive (dictionary) attack. </dd> 9965 9966 <dt><b>noanonymous</b></dt> 9967 9968 <dd>Disallow methods that allow anonymous authentication. </dd> 9969 9970 <dt><b>mutual_auth</b></dt> 9971 9972 <dd>Only allow methods that provide mutual authentication (not 9973 available with SASL version 1). </dd> 9974 9975 </dl> 9976 9977 <p> 9978 Example: 9979 </p> 9980 9981 <pre> 9982 <a href="postconf.5.html#smtp_sasl_security_options">smtp_sasl_security_options</a> = noplaintext 9983 </pre> 9984 9985 9986 </DD> 9987 9988 <DT><b><a name="smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a> 9989 (default: $<a href="postconf.5.html#smtp_sasl_security_options">smtp_sasl_security_options</a>)</b></DT><DD> 9990 9991 <p> The SASL authentication security options that the Postfix SMTP 9992 client uses for TLS encrypted SMTP sessions. </p> 9993 9994 <p> This feature is available in Postfix 2.2 and later. </p> 9995 9996 9997 </DD> 9998 9999 <DT><b><a name="smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a> 10000 (default: $<a href="postconf.5.html#smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a>)</b></DT><DD> 10001 10002 <p> The SASL authentication security options that the Postfix SMTP 10003 client uses for TLS encrypted SMTP sessions with a verified server 10004 certificate. </p> 10005 10006 <p> When mail is sent to the public MX host for the recipient's 10007 domain, server certificates are by default optional, and delivery 10008 proceeds even if certificate verification fails. For delivery via 10009 a submission service that requires SASL authentication, it may be 10010 appropriate to send plaintext passwords only when the connection 10011 to the server is strongly encrypted <b>and</b> the server identity 10012 is verified. </p> 10013 10014 <p> The <a href="postconf.5.html#smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a> parameter makes it 10015 possible to only enable plaintext mechanisms when a secure connection 10016 to the server is available. Submission servers subject to this 10017 policy must either have verifiable certificates or offer suitable 10018 non-plaintext SASL mechanisms. </p> 10019 10020 <p> This feature is available in Postfix 2.6 and later. </p> 10021 10022 10023 </DD> 10024 10025 <DT><b><a name="smtp_sasl_type">smtp_sasl_type</a> 10026 (default: cyrus)</b></DT><DD> 10027 10028 <p> The SASL plug-in type that the Postfix SMTP client should use 10029 for authentication. The available types are listed with the 10030 "<b>postconf -A</b>" command. </p> 10031 10032 <p> This feature is available in Postfix 2.3 and later. </p> 10033 10034 10035 </DD> 10036 10037 <DT><b><a name="smtp_send_xforward_command">smtp_send_xforward_command</a> 10038 (default: no)</b></DT><DD> 10039 10040 <p> 10041 Send the non-standard XFORWARD command when the Postfix SMTP server 10042 EHLO response announces XFORWARD support. 10043 </p> 10044 10045 <p> 10046 This allows an "smtp" delivery agent, used for injecting mail into 10047 a content filter, to forward the name, address, protocol and HELO 10048 name of the original client to the content filter and downstream 10049 queuing SMTP server. This can produce more useful logging than 10050 localhost[127.0.0.1] etc. 10051 </p> 10052 10053 <p> 10054 This feature is available in Postfix 2.1 and later. 10055 </p> 10056 10057 10058 </DD> 10059 10060 <DT><b><a name="smtp_sender_dependent_authentication">smtp_sender_dependent_authentication</a> 10061 (default: no)</b></DT><DD> 10062 10063 <p> 10064 Enable sender-dependent authentication in the Postfix SMTP client; this is 10065 available only with SASL authentication, and disables SMTP connection 10066 caching to ensure that mail from different senders will use the 10067 appropriate credentials. </p> 10068 10069 <p> 10070 This feature is available in Postfix 2.3 and later. 10071 </p> 10072 10073 10074 </DD> 10075 10076 <DT><b><a name="smtp_skip_4xx_greeting">smtp_skip_4xx_greeting</a> 10077 (default: yes)</b></DT><DD> 10078 10079 <p> 10080 Skip SMTP servers that greet with a 4XX status code (go away, try 10081 again later). 10082 </p> 10083 10084 <p> 10085 By default, Postfix moves on the next mail exchanger. Specify 10086 "<a href="postconf.5.html#smtp_skip_4xx_greeting">smtp_skip_4xx_greeting</a> = no" if Postfix should defer delivery 10087 immediately. 10088 </p> 10089 10090 <p> This feature is available in Postfix 2.0 and earlier. 10091 Later Postfix versions always skip SMTP servers that greet with a 10092 4XX status code. </p> 10093 10094 10095 </DD> 10096 10097 <DT><b><a name="smtp_skip_5xx_greeting">smtp_skip_5xx_greeting</a> 10098 (default: yes)</b></DT><DD> 10099 10100 <p> 10101 Skip SMTP servers that greet with a 5XX status code (go away, do 10102 not try again later). 10103 </p> 10104 10105 <p> By default, the Postfix SMTP client moves on the next mail 10106 exchanger. Specify "<a href="postconf.5.html#smtp_skip_5xx_greeting">smtp_skip_5xx_greeting</a> = no" if Postfix should 10107 bounce the mail immediately. The default setting is incorrect, but 10108 it is what a lot of people expect to happen. </p> 10109 10110 10111 </DD> 10112 10113 <DT><b><a name="smtp_skip_quit_response">smtp_skip_quit_response</a> 10114 (default: yes)</b></DT><DD> 10115 10116 <p> 10117 Do not wait for the response to the SMTP QUIT command. 10118 </p> 10119 10120 10121 </DD> 10122 10123 <DT><b><a name="smtp_starttls_timeout">smtp_starttls_timeout</a> 10124 (default: 300s)</b></DT><DD> 10125 10126 <p> Time limit for Postfix SMTP client write and read operations 10127 during TLS startup and shutdown handshake procedures. </p> 10128 10129 <p> This feature is available in Postfix 2.2 and later. </p> 10130 10131 10132 </DD> 10133 10134 <DT><b><a name="smtp_tls_CAfile">smtp_tls_CAfile</a> 10135 (default: empty)</b></DT><DD> 10136 10137 <p> A file containing CA certificates of root CAs trusted to sign 10138 either remote SMTP server certificates or intermediate CA certificates. 10139 These are loaded into memory before the <a href="smtp.8.html">smtp(8)</a> client enters the 10140 chroot jail. If the number of trusted roots is large, consider using 10141 <a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a> instead, but note that the latter directory must be 10142 present in the chroot jail if the <a href="smtp.8.html">smtp(8)</a> client is chrooted. This 10143 file may also be used to augment the client certificate trust chain, 10144 but it is best to include all the required certificates directly in 10145 $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>. </p> 10146 10147 <p> Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" to prevent Postfix from 10148 appending the system-supplied default CAs and trusting third-party 10149 certificates. </p> 10150 10151 <p> Example: </p> 10152 10153 <pre> 10154 <a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a> = /etc/postfix/CAcert.pem 10155 </pre> 10156 10157 <p> This feature is available in Postfix 2.2 and later. </p> 10158 10159 10160 </DD> 10161 10162 <DT><b><a name="smtp_tls_CApath">smtp_tls_CApath</a> 10163 (default: empty)</b></DT><DD> 10164 10165 <p> Directory with PEM format certificate authority certificates 10166 that the Postfix SMTP client uses to verify a remote SMTP server 10167 certificate. Don't forget to create the necessary "hash" links 10168 with, for example, "$OPENSSL_HOME/bin/c_rehash /etc/postfix/certs". 10169 </p> 10170 10171 <p> To use this option in chroot mode, this directory (or a copy) 10172 must be inside the chroot jail. </p> 10173 10174 <p> Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" to prevent Postfix from 10175 appending the system-supplied default CAs and trusting third-party 10176 certificates. </p> 10177 10178 <p> Example: </p> 10179 10180 <pre> 10181 <a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a> = /etc/postfix/certs 10182 </pre> 10183 10184 <p> This feature is available in Postfix 2.2 and later. </p> 10185 10186 10187 </DD> 10188 10189 <DT><b><a name="smtp_tls_block_early_mail_reply">smtp_tls_block_early_mail_reply</a> 10190 (default: no)</b></DT><DD> 10191 10192 <p> Try to detect a mail hijacking attack based on a TLS protocol 10193 vulnerability (CVE-2009-3555), where an attacker prepends malicious 10194 HELO, MAIL, RCPT, DATA commands to a Postfix SMTP client TLS session. 10195 The attack would succeed with non-Postfix SMTP servers that reply 10196 to the malicious HELO, MAIL, RCPT, DATA commands after negotiating 10197 the Postfix SMTP client TLS session. </p> 10198 10199 <p> This feature is available in Postfix 2.7. </p> 10200 10201 10202 </DD> 10203 10204 <DT><b><a name="smtp_tls_cert_file">smtp_tls_cert_file</a> 10205 (default: empty)</b></DT><DD> 10206 10207 <p> File with the Postfix SMTP client RSA certificate in PEM format. 10208 This file may also contain the Postfix SMTP client private RSA key, 10209 and these may be the same as the Postfix SMTP server RSA certificate and key 10210 file. </p> 10211 10212 <p> Do not configure client certificates unless you <b>must</b> present 10213 client TLS certificates to one or more servers. Client certificates are 10214 not usually needed, and can cause problems in configurations that work 10215 well without them. The recommended setting is to let the defaults stand: </p> 10216 10217 <blockquote> 10218 <pre> 10219 <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> = 10220 <a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a> = 10221 <a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> = 10222 <a href="postconf.5.html#smtp_tls_dkey_file">smtp_tls_dkey_file</a> = 10223 <a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a> = 10224 <a href="postconf.5.html#smtp_tls_eckey_file">smtp_tls_eckey_file</a> = 10225 </pre> 10226 </blockquote> 10227 10228 <p> The best way to use the default settings is to comment out the above 10229 parameters in <a href="postconf.5.html">main.cf</a> if present. </p> 10230 10231 <p> To enable remote SMTP servers to verify the Postfix SMTP client 10232 certificate, the issuing CA certificates must be made available to the 10233 server. You should include the required certificates in the client 10234 certificate file, the client certificate first, then the issuing 10235 CA(s) (bottom-up order). </p> 10236 10237 <p> Example: the certificate for "client.example.com" was issued by 10238 "intermediate CA" which itself has a certificate issued by "root CA". 10239 Create the client.pem file with "cat client_cert.pem intermediate_CA.pem 10240 root_CA.pem > client.pem". </p> 10241 10242 <p> If you also want to verify remote SMTP server certificates issued by 10243 these CAs, you can add the CA certificates to the <a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a>, in 10244 which case it is not necessary to have them in the <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>, 10245 <a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> or <a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>. </p> 10246 10247 <p> A certificate supplied here must be usable as an SSL client certificate 10248 and hence pass the "openssl verify -purpose sslclient ..." test. </p> 10249 10250 <p> Example: </p> 10251 10252 <pre> 10253 <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> = /etc/postfix/client.pem 10254 </pre> 10255 10256 <p> This feature is available in Postfix 2.2 and later. </p> 10257 10258 10259 </DD> 10260 10261 <DT><b><a name="smtp_tls_cipherlist">smtp_tls_cipherlist</a> 10262 (default: empty)</b></DT><DD> 10263 10264 <p> Obsolete Postfix < 2.3 control for the Postfix SMTP client TLS 10265 cipher list. As this feature applies to all TLS security levels, it is easy 10266 to create inter-operability problems by choosing a non-default cipher 10267 list. Do not use a non-default TLS cipher list on hosts that deliver email 10268 to the public Internet: you will be unable to send email to servers that 10269 only support the ciphers you exclude. Using a restricted cipher list 10270 may be more appropriate for an internal MTA, where one can exert some 10271 control over the TLS software and settings of the peer servers. </p> 10272 10273 <p> <b>Note:</b> do not use "" quotes around the parameter value. </p> 10274 10275 <p> This feature is available in Postfix version 2.2. It is not used with 10276 Postfix 2.3 and later; use <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> instead. </p> 10277 10278 10279 </DD> 10280 10281 <DT><b><a name="smtp_tls_ciphers">smtp_tls_ciphers</a> 10282 (default: export)</b></DT><DD> 10283 10284 <p> The minimum TLS cipher grade that the Postfix SMTP client 10285 will use with opportunistic TLS encryption. Cipher types listed in 10286 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> are excluded from the base definition of 10287 the selected cipher grade. The default value "export" ensures maximum 10288 inter-operability. Because encryption is optional, stronger controls 10289 are not appropriate, and this setting SHOULD NOT be changed unless the 10290 change is essential. </p> 10291 10292 <p> When TLS is mandatory the cipher grade is chosen via the 10293 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> configuration parameter, see there for syntax 10294 details. See <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for information on how to configure 10295 ciphers on a per-destination basis. </p> 10296 10297 <p> Example: </p> 10298 <pre> 10299 <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> = export 10300 </pre> 10301 10302 <p> This feature is available in Postfix 2.6 and later. With earlier Postfix 10303 releases only the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> parameter is implemented, 10304 and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p> 10305 10306 10307 </DD> 10308 10309 <DT><b><a name="smtp_tls_dcert_file">smtp_tls_dcert_file</a> 10310 (default: empty)</b></DT><DD> 10311 10312 <p> File with the Postfix SMTP client DSA certificate in PEM format. 10313 This file may also contain the Postfix SMTP client private DSA key. </p> 10314 10315 <p> See the discussion under <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> for more details. 10316 </p> 10317 10318 <p> Example: </p> 10319 10320 <pre> 10321 <a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> = /etc/postfix/client-dsa.pem 10322 </pre> 10323 10324 <p> This feature is available in Postfix 2.2 and later. </p> 10325 10326 10327 </DD> 10328 10329 <DT><b><a name="smtp_tls_dkey_file">smtp_tls_dkey_file</a> 10330 (default: $<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a>)</b></DT><DD> 10331 10332 <p> File with the Postfix SMTP client DSA private key in PEM format. 10333 This file may be combined with the Postfix SMTP client DSA certificate 10334 file specified with $<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a>. </p> 10335 10336 <p> The private key must be accessible without a pass-phrase, i.e. it 10337 must not be encrypted. File permissions should grant read-only 10338 access to the system superuser account ("root"), and no access 10339 to anyone else. </p> 10340 10341 <p> This feature is available in Postfix 2.2 and later. </p> 10342 10343 10344 </DD> 10345 10346 <DT><b><a name="smtp_tls_eccert_file">smtp_tls_eccert_file</a> 10347 (default: empty)</b></DT><DD> 10348 10349 <p> File with the Postfix SMTP client ECDSA certificate in PEM format. 10350 This file may also contain the Postfix SMTP client ECDSA private key. </p> 10351 10352 <p> See the discussion under <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> for more details. 10353 </p> 10354 10355 <p> Example: </p> 10356 10357 <pre> 10358 <a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a> = /etc/postfix/ecdsa-ccert.pem 10359 </pre> 10360 10361 <p> This feature is available in Postfix 2.6 and later, when Postfix is 10362 compiled and linked with OpenSSL 1.0.0 or later. </p> 10363 10364 10365 </DD> 10366 10367 <DT><b><a name="smtp_tls_eckey_file">smtp_tls_eckey_file</a> 10368 (default: $<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>)</b></DT><DD> 10369 10370 <p> File with the Postfix SMTP client ECDSA private key in PEM format. 10371 This file may be combined with the Postfix SMTP client ECDSA 10372 certificate file specified with $<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>. </p> 10373 10374 <p> The private key must be accessible without a pass-phrase, i.e. it 10375 must not be encrypted. File permissions should grant read-only 10376 access to the system superuser account ("root"), and no access 10377 to anyone else. </p> 10378 10379 <p> This feature is available in Postfix 2.6 and later, when Postfix is 10380 compiled and linked with OpenSSL 1.0.0 or later. </p> 10381 10382 10383 </DD> 10384 10385 <DT><b><a name="smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> 10386 (default: yes)</b></DT><DD> 10387 10388 <p> With mandatory TLS encryption, require that the remote SMTP 10389 server hostname matches the information in the remote SMTP server 10390 certificate. As of <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> the requirements for hostname checking 10391 for MTA clients are not specified. </p> 10392 10393 <p> This option can be set to "no" to disable strict peer name 10394 checking. This setting has no effect on sessions that are controlled 10395 via the <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> table. </p> 10396 10397 <p> Disabling the hostname verification can make sense in closed 10398 environment where special CAs are created. If not used carefully, 10399 this option opens the danger of a "man-in-the-middle" attack (the 10400 CommonName of this attacker will be logged). </p> 10401 10402 <p> This feature is available in Postfix 2.2 and later. With 10403 Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> instead. </p> 10404 10405 10406 </DD> 10407 10408 <DT><b><a name="smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> 10409 (default: empty)</b></DT><DD> 10410 10411 <p> List of ciphers or cipher types to exclude from the Postfix 10412 SMTP client cipher 10413 list at all TLS security levels. This is not an OpenSSL cipherlist, it is 10414 a simple list separated by whitespace and/or commas. The elements are a 10415 single cipher, or one or more "+" separated cipher properties, in which 10416 case only ciphers matching <b>all</b> the properties are excluded. </p> 10417 10418 <p> Examples (some of these will cause problems): </p> 10419 10420 <blockquote> 10421 <pre> 10422 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = aNULL 10423 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = MD5, DES 10424 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = DES+MD5 10425 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = AES256-SHA, DES-CBC3-MD5 10426 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = kEDH+aRSA 10427 </pre> 10428 </blockquote> 10429 10430 <p> The first setting, disables anonymous ciphers. The next setting 10431 disables ciphers that use the MD5 digest algorithm or the (single) DES 10432 encryption algorithm. The next setting disables ciphers that use MD5 and 10433 DES together. The next setting disables the two ciphers "AES256-SHA" 10434 and "DES-CBC3-MD5". The last setting disables ciphers that use "EDH" 10435 key exchange with RSA authentication. </p> 10436 10437 <p> This feature is available in Postfix 2.3 and later. </p> 10438 10439 10440 </DD> 10441 10442 <DT><b><a name="smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> 10443 (default: empty)</b></DT><DD> 10444 10445 <p> List of acceptable remote SMTP server certificate fingerprints 10446 for the "fingerprint" TLS security level (<b><a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a></b> = 10447 fingerprint). At this security level, certificate authorities are 10448 not used, and certificate expiration times are ignored. Instead, 10449 server certificates are verified directly via their "fingerprint". The 10450 fingerprint is a message digest of the server certificate. The digest 10451 algorithm is selected via the <b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a></b> 10452 parameter. </p> 10453 10454 <p> When an <b><a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a></b> table entry specifies the 10455 "fingerprint" security level, any "match" attributes in that entry specify 10456 the list of valid fingerprints for the corresponding destination. Multiple 10457 fingerprints can be combined with a "|" delimiter in a single match 10458 attribute, or multiple match attributes can be employed. </p> 10459 10460 <p> Example: Certificate fingerprint verification with internal mailhub. 10461 Two matching fingerprints are listed. The <a href="postconf.5.html#relayhost">relayhost</a> may be multiple 10462 physical hosts behind a load-balancer, each with its own private/public 10463 key and self-signed certificate. Alternatively, a single <a href="postconf.5.html#relayhost">relayhost</a> may 10464 be in the process of switching from one set of private/public keys to 10465 another, and both keys are trusted just prior to the transition. </p> 10466 10467 <blockquote> 10468 <pre> 10469 <a href="postconf.5.html#relayhost">relayhost</a> = [mailhub.example.com] 10470 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = fingerprint 10471 <a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> = md5 10472 <a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> = 10473 3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1 10474 EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35 10475 </pre> 10476 </blockquote> 10477 10478 <p> Example: Certificate fingerprint verification with selected destinations. 10479 As in the example above, we show two matching fingerprints: </p> 10480 10481 <blockquote> 10482 <pre> 10483 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 10484 <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> = hash:/etc/postfix/tls_policy 10485 <a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> = md5 10486 </pre> 10487 </blockquote> 10488 10489 <blockquote> 10490 <pre> 10491 /etc/postfix/tls_policy: 10492 example.com fingerprint 10493 match=3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1 10494 match=EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35 10495 </pre> 10496 </blockquote> 10497 10498 <p> This feature is available in Postfix 2.5 and later. </p> 10499 10500 10501 </DD> 10502 10503 <DT><b><a name="smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> 10504 (default: md5)</b></DT><DD> 10505 10506 <p> The message digest algorithm used to construct remote SMTP server 10507 certificate fingerprints. At the "fingerprint" TLS security level 10508 (<b><a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a></b> = fingerprint), the server certificate is 10509 verified by directly matching its <i>fingerprint</i>. The fingerprint 10510 is the message digest of the server certificate using the selected 10511 algorithm. With a digest algorithm resistant to "second pre-image" 10512 attacks, it is not feasible to create a new public key and a matching 10513 certificate that has the same fingerprint. </p> 10514 10515 <p> The default algorithm is <b>md5</b>; this is consistent with 10516 the backwards compatible setting of the digest used to verify client 10517 certificates in the SMTP server. </p> 10518 10519 <p> The best practice algorithm is now <b>sha1</b>. Recent advances in hash 10520 function cryptanalysis have led to md5 being deprecated in favor of sha1. 10521 However, as long as there are no known "second pre-image" attacks 10522 against md5, its use in this context can still be considered safe. 10523 </p> 10524 10525 <p> While additional digest algorithms are often available with OpenSSL's 10526 libcrypto, only those used by libssl in SSL cipher suites are available to 10527 Postfix. For now this means just md5 or sha1. </p> 10528 10529 <p> To find the fingerprint of a specific certificate file, with a 10530 specific digest algorithm, run: 10531 </p> 10532 10533 <blockquote> 10534 <pre> 10535 $ openssl x509 -noout -fingerprint -<i>digest</i> -in <i>certfile</i>.pem 10536 </pre> 10537 </blockquote> 10538 10539 <p> The text to the right of "=" sign is the desired fingerprint. 10540 For example: </p> 10541 10542 <blockquote> 10543 <pre> 10544 $ openssl x509 -noout -fingerprint -sha1 -in cert.pem 10545 SHA1 Fingerprint=D4:6A:AB:19:24:79:F8:32:BB:A6:CB:66:82:C0:8E:9B:EE:29:A8:1A 10546 </pre> 10547 </blockquote> 10548 10549 <p> This feature is available in Postfix 2.5 and later. </p> 10550 10551 10552 </DD> 10553 10554 <DT><b><a name="smtp_tls_key_file">smtp_tls_key_file</a> 10555 (default: $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>)</b></DT><DD> 10556 10557 <p> File with the Postfix SMTP client RSA private key in PEM format. 10558 This file may be combined with the Postfix SMTP client RSA certificate 10559 file specified with $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>. </p> 10560 10561 <p> The private key must be accessible without a pass-phrase, i.e. it 10562 must not be encrypted. File permissions should grant read-only 10563 access to the system superuser account ("root"), and no access 10564 to anyone else. </p> 10565 10566 <p> Example: </p> 10567 10568 <pre> 10569 <a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a> = $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> 10570 </pre> 10571 10572 <p> This feature is available in Postfix 2.2 and later. </p> 10573 10574 10575 </DD> 10576 10577 <DT><b><a name="smtp_tls_loglevel">smtp_tls_loglevel</a> 10578 (default: 0)</b></DT><DD> 10579 10580 <p> Enable additional Postfix SMTP client logging of TLS activity. 10581 Each logging level also includes the information that is logged at 10582 a lower logging level. </p> 10583 10584 <dl compact> 10585 10586 <dt> </dt> <dd> 0 Disable logging of TLS activity. </dd> 10587 10588 <dt> </dt> <dd> 1 Log TLS handshake and certificate information. </dd> 10589 10590 <dt> </dt> <dd> 2 Log levels during TLS negotiation. </dd> 10591 10592 <dt> </dt> <dd> 3 Log hexadecimal and ASCII dump of TLS negotiation 10593 process. </dd> 10594 10595 <dt> </dt> <dd> 4 Log hexadecimal and ASCII dump of complete 10596 transmission after STARTTLS. </dd> 10597 10598 </dl> 10599 10600 <p> Use "<a href="postconf.5.html#smtp_tls_loglevel">smtp_tls_loglevel</a> = 3" only in case of problems. Use of 10601 loglevel 4 is strongly discouraged. </p> 10602 10603 <p> This feature is available in Postfix 2.2 and later. </p> 10604 10605 10606 </DD> 10607 10608 <DT><b><a name="smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> 10609 (default: medium)</b></DT><DD> 10610 10611 <p> The minimum TLS cipher grade that the Postfix SMTP client will 10612 use with 10613 mandatory TLS encryption. The default value "medium" is suitable 10614 for most destinations with which you may want to enforce TLS, and 10615 is beyond the reach of today's cryptanalytic methods. See 10616 <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for information on how to configure ciphers 10617 on a per-destination basis. </p> 10618 10619 <p> The following cipher grades are supported: </p> 10620 10621 <dl> 10622 <dt><b>export</b></dt> 10623 <dd> Enable "EXPORT" grade or better OpenSSL 10624 ciphers. This is the default for opportunistic encryption. It is 10625 not recommended for mandatory encryption unless you must enforce TLS 10626 with "crippled" peers. The underlying cipherlist is specified via the 10627 <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> configuration parameter, which you are strongly 10628 encouraged to not change. </dd> 10629 10630 <dt><b>low</b></dt> 10631 <dd> Enable "LOW" grade or better OpenSSL ciphers. This 10632 setting is only appropriate for internal mail servers. The underlying 10633 cipherlist is specified via the <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> configuration 10634 parameter, which you are strongly encouraged to not change. </dd> 10635 10636 <dt><b>medium</b></dt> 10637 <dd> Enable "MEDIUM" grade or better OpenSSL ciphers. 10638 The underlying cipherlist is specified via the <a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> 10639 configuration parameter, which you are strongly encouraged to not change. 10640 </dd> 10641 10642 <dt><b>high</b></dt> 10643 <dd> Enable only "HIGH" grade OpenSSL ciphers. This setting may 10644 be appropriate when all mandatory TLS destinations (e.g. when all 10645 mail is routed to a suitably capable <a href="postconf.5.html#relayhost">relayhost</a>) support at least one 10646 "HIGH" grade cipher. The underlying cipherlist is specified via the 10647 <a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a> configuration parameter, which you are strongly 10648 encouraged to not change. </dd> 10649 10650 <dt><b>null</b></dt> 10651 <dd> Enable only the "NULL" OpenSSL ciphers, these provide authentication 10652 without encryption. This setting is only appropriate in the rare case 10653 that all servers are prepared to use NULL ciphers (not normally enabled 10654 in TLS servers). A plausible use-case is an LMTP server listening on a 10655 UNIX-domain socket that is configured to support "NULL" ciphers. The 10656 underlying cipherlist is specified via the <a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a> 10657 configuration parameter, which you are strongly encouraged to not 10658 change. </dd> 10659 10660 </dl> 10661 10662 <p> The underlying cipherlists for grades other than "null" include 10663 anonymous ciphers, but these are automatically filtered out if the 10664 Postfix SMTP client is configured to verify server certificates. 10665 You are very unlikely to need to take any steps to exclude anonymous 10666 ciphers, they are excluded automatically as necessary. If you must 10667 exclude anonymous ciphers at the "may" or "encrypt" security levels, 10668 when the Postfix SMTP client does not need or use peer certificates, set 10669 "<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = aNULL". To exclude anonymous ciphers only when 10670 TLS is enforced, set "<a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> = aNULL". </p> 10671 10672 <p> This feature is available in Postfix 2.3 and later. </p> 10673 10674 10675 </DD> 10676 10677 <DT><b><a name="smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> 10678 (default: empty)</b></DT><DD> 10679 10680 <p> Additional list of ciphers or cipher types to exclude from the 10681 SMTP client cipher list at mandatory TLS security levels. This list 10682 works in addition to the exclusions listed with <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> 10683 (see there for syntax details). </p> 10684 10685 <p> Starting with Postfix 2.6, the mandatory cipher exclusions can be 10686 specified on a per-destination basis via the TLS policy "exclude" 10687 attribute. See <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for notes and examples. </p> 10688 10689 <p> This feature is available in Postfix 2.3 and later. </p> 10690 10691 10692 </DD> 10693 10694 <DT><b><a name="smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> 10695 (default: !SSLv2)</b></DT><DD> 10696 10697 <p> List of SSL/TLS protocols that the Postfix SMTP client will use with 10698 mandatory TLS encryption. In <a href="postconf.5.html">main.cf</a> the values are separated by 10699 whitespace, commas or colons. In the policy table "protocols" attribute 10700 (see <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) the only valid separator is colon. An 10701 empty value means allow all protocols. The valid protocol names, (see 10702 <b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" and "TLSv1". </p> 10703 10704 <p> Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1" 10705 and "TLSv1.2". If an older Postfix version is linked against OpenSSL 10706 1.0.1 or later, these, or any other new protocol versions, are 10707 unconditionally enabled. </p> 10708 10709 <p> With Postfix ≥ 2.5 the parameter syntax is expanded to support 10710 protocol exclusions. One can now explicitly exclude SSLv2 by setting 10711 "<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2". To exclude both SSLv2 and 10712 SSLv3 set "<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !SSLv3". Listing 10713 the protocols to include, rather than protocols to exclude, is 10714 supported, but not recommended. The exclusion form more closely 10715 matches the behaviour when the OpenSSL library is newer than Postfix. 10716 </p> 10717 10718 <p> Since SSL version 2 has known protocol weaknesses and is now 10719 deprecated, the default setting excludes "SSLv2". This means that by 10720 default, SSL version 2 will not be used at the "encrypt" security level 10721 and higher. </p> 10722 10723 <p> See the documentation of the <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> parameter and 10724 <a href="TLS_README.html">TLS_README</a> for more information about security levels. </p> 10725 10726 <p> Example: </p> 10727 10728 <pre> 10729 # Preferred form with Postfix ≥ 2.5: 10730 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !SSLv3 10731 # Alternative form. 10732 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = TLSv1 10733 </pre> 10734 10735 <p> This feature is available in Postfix 2.3 and later. </p> 10736 10737 10738 </DD> 10739 10740 <DT><b><a name="smtp_tls_note_starttls_offer">smtp_tls_note_starttls_offer</a> 10741 (default: no)</b></DT><DD> 10742 10743 <p> Log the hostname of a remote SMTP server that offers STARTTLS, 10744 when TLS is not already enabled for that server. </p> 10745 10746 <p> The logfile record looks like: </p> 10747 10748 <pre> 10749 postfix/smtp[pid]: Host offered STARTTLS: [name.of.host] 10750 </pre> 10751 10752 <p> This feature is available in Postfix 2.2 and later. </p> 10753 10754 10755 </DD> 10756 10757 <DT><b><a name="smtp_tls_per_site">smtp_tls_per_site</a> 10758 (default: empty)</b></DT><DD> 10759 10760 <p> Optional lookup tables with the Postfix SMTP client TLS usage 10761 policy by next-hop destination and by remote SMTP server hostname. 10762 When both lookups succeed, the more specific per-site policy (NONE, 10763 MUST, etc) overrides the less specific one (MAY), and the more secure 10764 per-site policy (MUST, etc) overrides the less secure one (NONE). 10765 With Postfix 2.3 and later <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> is strongly discouraged: 10766 use <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> instead. </p> 10767 10768 <p> Use of the bare hostname as the per-site table lookup key is 10769 discouraged. Always use the full destination nexthop (enclosed in 10770 [] with a possible ":port" suffix). A recipient domain or MX-enabled 10771 transport next-hop with no port suffix may look like a bare hostname, 10772 but is still a suitable <i>destination</i>. </p> 10773 10774 <p> Specify a next-hop destination or server hostname on the left-hand 10775 side; no wildcards are allowed. The next-hop destination is either 10776 the recipient domain, or the destination specified with a <a href="transport.5.html">transport(5)</a> 10777 table, the <a href="postconf.5.html#relayhost">relayhost</a> parameter, or the <a href="postconf.5.html#relay_transport">relay_transport</a> parameter. 10778 On the right hand side specify one of the following keywords: </p> 10779 10780 <dl> 10781 10782 <dt> NONE </dt> <dd> Don't use TLS at all. This overrides a less 10783 specific <b>MAY</b> lookup result from the alternate host or next-hop 10784 lookup key, and overrides the global <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>, <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a>, 10785 and <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> settings. </dd> 10786 10787 <dt> MAY </dt> <dd> Try to use TLS if the server announces support, 10788 otherwise use the unencrypted connection. This has less precedence 10789 than a more specific result (including <b>NONE</b>) from the alternate 10790 host or next-hop lookup key, and has less precedence than the more 10791 specific global "<a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a> = yes" or "<a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> 10792 = yes". </dd> 10793 10794 <dt> MUST_NOPEERMATCH </dt> <dd> Require TLS encryption, but do not 10795 require that the remote SMTP server hostname matches the information 10796 in the remote SMTP server certificate, or that the server certificate 10797 was issued by a trusted CA. This overrides a less secure <b>NONE</b> 10798 or a less specific <b>MAY</b> lookup result from the alternate host 10799 or next-hop lookup key, and overrides the global <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>, 10800 <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a> and <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> settings. </dd> 10801 10802 <dt> MUST </dt> <dd> Require TLS encryption, require that the remote 10803 SMTP server hostname matches the information in the remote SMTP 10804 server certificate, and require that the remote SMTP server certificate 10805 was issued by a trusted CA. This overrides a less secure <b>NONE</b> 10806 and <b>MUST_NOPEERMATCH</b> or a less specific <b>MAY</b> lookup 10807 result from the alternate host or next-hop lookup key, and overrides 10808 the global <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>, <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a> and <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> 10809 settings. </dd> 10810 10811 </dl> 10812 10813 <p> The above keywords correspond to the "none", "may", "encrypt" and 10814 "verify" security levels for the new <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> parameter 10815 introduced in Postfix 2.3. Starting with Postfix 2.3, and independently 10816 of how the policy is specified, the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and 10817 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> parameters apply when TLS encryption 10818 is mandatory. Connections for which encryption is optional typically 10819 enable all "export" grade and better ciphers (see <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> 10820 and <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>). </p> 10821 10822 <p> As long as no secure DNS lookup mechanism is available, false 10823 hostnames in MX or CNAME responses can change the server hostname 10824 that Postfix uses for TLS policy lookup and server certificate 10825 verification. Even with a perfect match between the server hostname and 10826 the server certificate, there is no guarantee that Postfix is connected 10827 to the right server. See <a href="TLS_README.html">TLS_README</a> (Closing a DNS loophole with obsolete 10828 per-site TLS policies) for a possible work-around. </p> 10829 10830 <p> This feature is available in Postfix 2.2 and later. With 10831 Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> instead. </p> 10832 10833 10834 </DD> 10835 10836 <DT><b><a name="smtp_tls_policy_maps">smtp_tls_policy_maps</a> 10837 (default: empty)</b></DT><DD> 10838 10839 <p> Optional lookup tables with the Postfix SMTP client TLS security 10840 policy by next-hop destination; when a non-empty value is specified, 10841 this overrides the obsolete <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> parameter. See 10842 <a href="TLS_README.html">TLS_README</a> for a more detailed discussion of TLS security levels. 10843 </p> 10844 10845 <p> The TLS policy table is indexed by the full next-hop destination, 10846 which is either the recipient domain, or the verbatim next-hop 10847 specified in the transport table, $<a href="postconf.5.html#local_transport">local_transport</a>, $<a href="postconf.5.html#virtual_transport">virtual_transport</a>, 10848 $<a href="postconf.5.html#relay_transport">relay_transport</a> or $<a href="postconf.5.html#default_transport">default_transport</a>. This includes any enclosing 10849 square brackets and any non-default destination server port suffix. The 10850 LMTP socket type prefix (inet: or unix:) is not included in the lookup 10851 key. </p> 10852 10853 <p> Only the next-hop domain, or $<a href="postconf.5.html#myhostname">myhostname</a> with LMTP over UNIX-domain 10854 sockets, is used as the nexthop name for certificate verification. The 10855 port and any enclosing square brackets are used in the table lookup key, 10856 but are not used for server name verification. </p> 10857 10858 <p> When the lookup key is a domain name without enclosing square brackets 10859 or any <i>:port</i> suffix (typically the recipient domain), and the full 10860 domain is not found in the table, just as with the <a href="transport.5.html">transport(5)</a> table, 10861 the parent domain starting with a leading "." is matched recursively. This 10862 allows one to specify a security policy for a recipient domain and all 10863 its sub-domains. </p> 10864 10865 <p> The lookup result is a security level, followed by an optional list 10866 of whitespace and/or comma separated name=value attributes that override 10867 related <a href="postconf.5.html">main.cf</a> settings. The TLS security levels in order of increasing 10868 security are: </p> 10869 10870 <dl> 10871 10872 <dt><b>none</b></dt> 10873 <dd>No TLS. No additional attributes are supported at this level. </dd> 10874 10875 <dt><b>may</b></dt> 10876 <dd>Opportunistic TLS. Since sending in the clear is acceptable, 10877 demanding stronger than default TLS security merely reduces 10878 inter-operability. The optional "ciphers", "exclude" and "protocols" 10879 attributes (available for opportunistic TLS with Postfix ≥ 2.6) 10880 override the "<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>", "<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a>" and 10881 "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>" configuration parameters. When opportunistic TLS 10882 handshakes fail, Postfix retries the connection with TLS disabled. 10883 This allows mail delivery to sites with non-interoperable TLS 10884 implementations.</dd> 10885 10886 <dt><b>encrypt</b></dt> <dd>Mandatory TLS encryption. At this level 10887 and higher, the optional "protocols" attribute overrides the <a href="postconf.5.html">main.cf</a> 10888 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> parameter, the optional "ciphers" attribute 10889 overrides the <a href="postconf.5.html">main.cf</a> <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> parameter, and the 10890 optional "exclude" attribute (Postfix ≥ 2.6) overrides the <a href="postconf.5.html">main.cf</a> 10891 <a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> parameter. In the policy table, 10892 multiple protocols or excluded ciphers must be separated by colons, 10893 as attribute values may not contain whitespace or commas. </dd> 10894 10895 <dt><b>fingerprint</b></dt> <dd>Certificate fingerprint 10896 verification. Available with Postfix 2.5 and later. At this security 10897 level, there are no trusted certificate authorities. The certificate 10898 trust chain, expiration date, ... are not checked. Instead, 10899 the optional <b>match</b> attribute, or else the <a href="postconf.5.html">main.cf</a> 10900 <b><a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a></b> parameter, lists the 10901 valid "fingerprints" of the server certificate. The digest 10902 algorithm used to calculate the fingerprint is selected by the 10903 <b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a></b> parameter. Multiple fingerprints can 10904 be combined with a "|" delimiter in a single match attribute, or multiple 10905 match attributes can be employed. The ":" character is not used as a 10906 delimiter as it occurs between each pair of fingerprint (hexadecimal) 10907 digits. </dd> 10908 10909 <dt><b>verify</b></dt> <dd>Mandatory TLS verification. At this security 10910 level, DNS MX lookups are trusted to be secure enough, and the name 10911 verified in the server certificate is usually obtained indirectly via 10912 unauthenticated DNS MX lookups. The optional "match" attribute overrides 10913 the <a href="postconf.5.html">main.cf</a> <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> parameter. In the policy table, 10914 multiple match patterns and strategies must be separated by colons. 10915 In practice explicit control over matching is more common with the 10916 "secure" policy, described below. </dd> 10917 10918 <dt><b>secure</b></dt> <dd>Secure-channel TLS. At this security level, DNS 10919 MX lookups, though potentially used to determine the candidate next-hop 10920 gateway IP addresses, are <b>not</b> trusted to be secure enough for TLS 10921 peername verification. Instead, the default name verified in the server 10922 certificate is obtained directly from the next-hop, or is explicitly 10923 specified via the optional <b>match</b> attribute which overrides the 10924 <a href="postconf.5.html">main.cf</a> <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> parameter. In the policy table, 10925 multiple match patterns and strategies must be separated by colons. 10926 The match attribute is most useful when multiple domains are supported by 10927 common server, the policy entries for additional domains specify matching 10928 rules for the primary domain certificate. While transport table overrides 10929 routing the secondary domains to the primary nexthop also allow secure 10930 verification, they risk delivery to the wrong destination when domains 10931 change hands or are re-assigned to new gateways. With the "match" 10932 attribute approach, routing is not perturbed, and mail is deferred if 10933 verification of a new MX host fails. </dd> 10934 10935 </dl> 10936 10937 <p> 10938 Example: 10939 </p> 10940 10941 <pre> 10942 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 10943 <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> = hash:/etc/postfix/tls_policy 10944 # Postfix 2.5 and later 10945 <a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> = md5 10946 </pre> 10947 10948 <pre> 10949 /etc/postfix/tls_policy: 10950 example.edu none 10951 example.mil may 10952 example.gov encrypt protocols=TLSv1 10953 example.com verify ciphers=high 10954 example.net secure 10955 .example.net secure match=.example.net:example.net 10956 [mail.example.org]:587 secure match=nexthop 10957 # Postfix 2.5 and later 10958 [thumb.example.org] fingerprint 10959 match=EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35 10960 match=3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1 10961 </pre> 10962 10963 <p> <b>Note:</b> The <b>hostname</b> strategy if listed in a non-default 10964 setting of <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> or in the <b>match</b> attribute 10965 in the policy table can render the <b>secure</b> level vulnerable to 10966 DNS forgery. Do not use the <b>hostname</b> strategy for secure-channel 10967 configurations in environments where DNS security is not assured. </p> 10968 10969 <p> This feature is available in Postfix 2.3 and later. </p> 10970 10971 10972 </DD> 10973 10974 <DT><b><a name="smtp_tls_protocols">smtp_tls_protocols</a> 10975 (default: !SSLv2)</b></DT><DD> 10976 10977 <p> List of TLS protocols that the Postfix SMTP client will exclude or 10978 include with opportunistic TLS encryption. Starting with Postfix 2.6, 10979 the Postfix SMTP client will by default not use the obsolete SSLv2 10980 protocol. </p> 10981 10982 <p> In <a href="postconf.5.html">main.cf</a> the values are separated by whitespace, commas or 10983 colons. In the policy table (see <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) the only valid 10984 separator is colon. An empty value means allow all protocols. The valid 10985 protocol names, (see <b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" 10986 and "TLSv1". </p> 10987 10988 <p> Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1" 10989 and "TLSv1.2". If an older Postfix version is linked against OpenSSL 10990 1.0.1 or later, these, or any other new protocol versions, are 10991 unconditionally enabled. </p> 10992 10993 <p> To include a protocol list its name, to exclude it, prefix the name 10994 with a "!" character. To exclude SSLv2 even for opportunistic TLS set 10995 "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2". To exclude both "SSLv2" and "SSLv3" set 10996 "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2, !SSLv3". Explicitly listing the protocols to 10997 include, rather than protocols to exclude, is supported, but not 10998 recommended. The exclusion form more closely matches the behaviour 10999 when the OpenSSL library is newer than Postfix. </p> 11000 11001 <p> Example: </p> 11002 <pre> 11003 # TLSv1 only! 11004 <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2, !SSLv3 11005 </pre> 11006 11007 <p> This feature is available in Postfix 2.6 and later. </p> 11008 11009 11010 </DD> 11011 11012 <DT><b><a name="smtp_tls_scert_verifydepth">smtp_tls_scert_verifydepth</a> 11013 (default: 9)</b></DT><DD> 11014 11015 <p> The verification depth for remote SMTP server certificates. A depth 11016 of 1 is sufficient if the issuing CA is listed in a local CA file. </p> 11017 11018 <p> The default verification depth is 9 (the OpenSSL default) for 11019 compatibility with earlier Postfix behavior. Prior to Postfix 2.5, 11020 the default value was 5, but the limit was not actually enforced. If 11021 you have set this to a lower non-default value, certificates with longer 11022 trust chains may now fail to verify. Certificate chains with 1 or 2 11023 CAs are common, deeper chains are more rare and any number between 5 11024 and 9 should suffice in practice. You can choose a lower number if, 11025 for example, you trust certificates directly signed by an issuing CA 11026 but not any CAs it delegates to. </p> 11027 11028 <p> This feature is available in Postfix 2.2 and later. </p> 11029 11030 11031 </DD> 11032 11033 <DT><b><a name="smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> 11034 (default: nexthop, dot-nexthop)</b></DT><DD> 11035 11036 <p> The server certificate peername verification method for the 11037 "secure" TLS security level. In a "secure" TLS policy table 11038 ($<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) entry the optional "match" attribute 11039 overrides this <a href="postconf.5.html">main.cf</a> setting. </p> 11040 11041 <p> This parameter specifies one or more patterns or strategies separated 11042 by commas, whitespace or colons. In the policy table the only valid 11043 separator is the colon character. </p> 11044 11045 <p> For a description of the pattern and strategy syntax see the 11046 <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> parameter. The "hostname" strategy should 11047 be avoided in this context, as in the absence of a secure global DNS, using 11048 the results of MX lookups in certificate verification is not immune to active 11049 (man-in-the-middle) attacks on DNS. </p> 11050 11051 <p> 11052 Sample <a href="postconf.5.html">main.cf</a> setting: 11053 </p> 11054 11055 <blockquote> 11056 <pre> 11057 <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> = nexthop 11058 </pre> 11059 </blockquote> 11060 11061 <p> 11062 Sample policy table override: 11063 </p> 11064 11065 <blockquote> 11066 <pre> 11067 example.net secure match=example.com:.example.com 11068 .example.net secure match=example.com:.example.com 11069 </pre> 11070 </blockquote> 11071 11072 <p> This feature is available in Postfix 2.3 and later. </p> 11073 11074 11075 </DD> 11076 11077 <DT><b><a name="smtp_tls_security_level">smtp_tls_security_level</a> 11078 (default: empty)</b></DT><DD> 11079 11080 <p> The default SMTP TLS security level for the Postfix SMTP client; 11081 when a non-empty value is specified, this overrides the obsolete 11082 parameters <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>, <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a>, and <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a>. 11083 </p> 11084 11085 <p> Specify one of the following security levels: </p> 11086 11087 <dl> 11088 11089 <dt><b>none</b></dt> <dd> TLS will not be used unless enabled for specific 11090 destinations via <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>. </dd> 11091 11092 <dt><b>may</b></dt> 11093 <dd> Opportunistic TLS. Use TLS if this is supported by the remote 11094 SMTP server, otherwise use plaintext. Since 11095 sending in the clear is acceptable, demanding stronger than default TLS 11096 security merely reduces inter-operability. 11097 The "<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>" and "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>" (Postfix ≥ 2.6) 11098 configuration parameters provide control over the protocols and 11099 cipher grade used with opportunistic TLS. With earlier releases the 11100 opportunistic TLS cipher grade is always "export" and no protocols 11101 are disabled. 11102 When TLS handshakes fail, the connection is retried with TLS disabled. 11103 This allows mail delivery to sites with non-interoperable TLS 11104 implementations. </dd> 11105 11106 <dt><b>encrypt</b></dt> <dd>Mandatory TLS encryption. Since a minimum 11107 level of security is intended, it is reasonable to be specific about 11108 sufficiently secure protocol versions and ciphers. At this security level 11109 and higher, the <a href="postconf.5.html">main.cf</a> parameters <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> and 11110 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> specify the TLS protocols and minimum 11111 cipher grade which the administrator considers secure enough for 11112 mandatory encrypted sessions. This security level is not an appropriate 11113 default for systems delivering mail to the Internet. </dd> 11114 11115 <dt><b>fingerprint</b></dt> <dd>Certificate fingerprint 11116 verification. Available with Postfix 2.5 and later. At this security 11117 level, there are no trusted certificate authorities. The certificate 11118 trust chain, expiration date, ... are not checked. Instead, 11119 the <b><a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a></b> parameter lists 11120 the valid "fingerprints" of the server certificate. The digest 11121 algorithm used to calculate the fingerprint is selected by the 11122 <b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a></b> parameter. </dd> 11123 11124 <dt><b>verify</b></dt> <dd>Mandatory TLS verification. At this security 11125 level, DNS MX lookups are trusted to be secure enough, and the name 11126 verified in the server certificate is usually obtained indirectly 11127 via unauthenticated DNS MX lookups. The <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> 11128 parameter controls how the server name is verified. In practice explicit 11129 control over matching is more common at the "secure" level, described 11130 below. This security level is not an appropriate default for systems 11131 delivering mail to the Internet. </dd> 11132 11133 <dt><b>secure</b></dt> <dd>Secure-channel TLS. At this security level, 11134 DNS MX lookups, though potentially used to determine the candidate 11135 next-hop gateway IP addresses, are <b>not</b> trusted to be secure enough 11136 for TLS peername verification. Instead, the default name verified in 11137 the server certificate is obtained from the next-hop domain as specified 11138 in the <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> configuration parameter. The default 11139 matching rule is that a server certificate matches when its name is equal 11140 to or is a sub-domain of the nexthop domain. This security level is not 11141 an appropriate default for systems delivering mail to the Internet. </dd> 11142 11143 </dl> 11144 11145 <p> 11146 Examples: 11147 </p> 11148 11149 <pre> 11150 # No TLS. Formerly: <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>=no and <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a>=no. 11151 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = none 11152 </pre> 11153 11154 <pre> 11155 # Opportunistic TLS. 11156 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = may 11157 # Postfix ≥ 2.6: 11158 # Do not tweak opportunistic ciphers or protocol unless it is essential 11159 # to do so (if a security vulnerability is found in the SSL library that 11160 # can be mitigated by disabling a particular protocol or raising the 11161 # cipher grade from "export" to "low" or "medium"). 11162 <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> = export 11163 <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2 11164 </pre> 11165 11166 <pre> 11167 # Mandatory (high-grade) TLS encryption. 11168 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = encrypt 11169 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high 11170 </pre> 11171 11172 <pre> 11173 # Mandatory TLS verification of hostname or nexthop domain. 11174 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = verify 11175 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high 11176 <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> = hostname, nexthop, dot-nexthop 11177 </pre> 11178 11179 <pre> 11180 # Secure channel TLS with exact nexthop name match. 11181 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = secure 11182 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = TLSv1 11183 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high 11184 <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> = nexthop 11185 </pre> 11186 11187 <pre> 11188 # Certificate fingerprint verification (Postfix ≥ 2.5). 11189 # The CA-less "fingerprint" security level only scales to a limited 11190 # number of destinations. As a global default rather than a per-site 11191 # setting, this is practical when mail for all recipients is sent 11192 # to a central mail hub. 11193 <a href="postconf.5.html#relayhost">relayhost</a> = [mailhub.example.com] 11194 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = fingerprint 11195 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !SSLv3 11196 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high 11197 <a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> = 11198 3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1 11199 EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35 11200 </pre> 11201 11202 <p> This feature is available in Postfix 2.3 and later. </p> 11203 11204 11205 </DD> 11206 11207 <DT><b><a name="smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> 11208 (default: empty)</b></DT><DD> 11209 11210 <p> Name of the file containing the optional Postfix SMTP client 11211 TLS session cache. Specify a database type that supports enumeration, 11212 such as <b>btree</b> or <b>sdbm</b>; there is no need to support 11213 concurrent access. The file is created if it does not exist. The <a href="smtp.8.html">smtp(8)</a> 11214 daemon does not use this parameter directly, rather the cache is 11215 implemented indirectly in the <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon. This means that 11216 per-smtp-instance <a href="master.5.html">master.cf</a> overrides of this parameter are not effective. 11217 Note, that each of the cache databases supported by <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon: 11218 $<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a>, $<a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> 11219 (and with Postfix 2.3 and later $<a href="postconf.5.html#lmtp_tls_session_cache_database">lmtp_tls_session_cache_database</a>), needs to 11220 be stored separately. It is not at this time possible to store multiple 11221 caches in a single database. </p> 11222 11223 <p> Note: <b>dbm</b> databases are not suitable. TLS 11224 session objects are too large. </p> 11225 11226 <p> As of version 2.5, Postfix no longer uses root privileges when 11227 opening this file. The file should now be stored under the Postfix-owned 11228 <a href="postconf.5.html#data_directory">data_directory</a>. As a migration aid, an attempt to open the file 11229 under a non-Postfix directory is redirected to the Postfix-owned 11230 <a href="postconf.5.html#data_directory">data_directory</a>, and a warning is logged. </p> 11231 11232 <p> Example: </p> 11233 11234 <pre> 11235 <a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> = btree:/var/db/postfix/smtp_scache 11236 </pre> 11237 11238 <p> This feature is available in Postfix 2.2 and later. </p> 11239 11240 11241 </DD> 11242 11243 <DT><b><a name="smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a> 11244 (default: 3600s)</b></DT><DD> 11245 11246 <p> The expiration time of Postfix SMTP client TLS session cache 11247 information. A cache cleanup is performed periodically 11248 every $<a href="postconf.5.html#smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a> seconds. As with 11249 $<a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a>, this parameter is implemented in the 11250 <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon and therefore per-smtp-instance <a href="master.5.html">master.cf</a> overrides 11251 are not possible. </p> 11252 11253 <p> This feature is available in Postfix 2.2 and later. </p> 11254 11255 11256 </DD> 11257 11258 <DT><b><a name="smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> 11259 (default: hostname)</b></DT><DD> 11260 11261 <p> The server certificate peername verification method for the 11262 "verify" TLS security level. In a "verify" TLS policy table 11263 ($<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) entry the optional "match" attribute 11264 overrides this <a href="postconf.5.html">main.cf</a> setting. </p> 11265 11266 <p> This parameter specifies one or more patterns or strategies separated 11267 by commas, whitespace or colons. In the policy table the only valid 11268 separator is the colon character. </p> 11269 11270 <p> Patterns specify domain names, or domain name suffixes: </p> 11271 11272 <dl> 11273 11274 <dt><i>example.com</i></dt> <dd> Match the <i>example.com</i> domain, 11275 i.e. one of the names the server certificate must be <i>example.com</i>, 11276 upper and lower case distinctions are ignored. </dd> 11277 11278 <dt><i>.example.com</i></dt> 11279 <dd> Match subdomains of the <i>example.com</i> domain, i.e. match 11280 a name in the server certificate that consists of a non-zero number of 11281 labels followed by a <i>.example.com</i> suffix. Case distinctions are 11282 ignored.</dd> 11283 11284 </dl> 11285 11286 <p> Strategies specify a transformation from the next-hop domain 11287 to the expected name in the server certificate: </p> 11288 11289 <dl> 11290 11291 <dt>nexthop</dt> 11292 <dd> Match against the next-hop domain, which is either the recipient 11293 domain, or the transport next-hop configured for the domain stripped of 11294 any optional socket type prefix, enclosing square brackets and trailing 11295 port. When MX lookups are not suppressed, this is the original nexthop 11296 domain prior to the MX lookup, not the result of the MX lookup. For 11297 LMTP delivery via UNIX-domain sockets, the verified next-hop name is 11298 $<a href="postconf.5.html#myhostname">myhostname</a>. This strategy is suitable for use with the "secure" 11299 policy. Case is ignored.</dd> 11300 11301 <dt>dot-nexthop</dt> 11302 <dd> As above, but match server certificate names that are subdomains 11303 of the next-hop domain. Case is ignored.</dd> 11304 11305 <dt>hostname</dt> <dd> Match against the hostname of the server, often 11306 obtained via an unauthenticated DNS MX lookup. For LMTP delivery via 11307 UNIX-domain sockets, the verified name is $<a href="postconf.5.html#myhostname">myhostname</a>. This matches 11308 the verification strategy of the "MUST" keyword in the obsolete 11309 <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> table, and is suitable for use with the "verify" 11310 security level. When the next-hop name is enclosed in square brackets 11311 to suppress MX lookups, the "hostname" strategy is the same as the 11312 "nexthop" strategy. Case is ignored.</dd> 11313 11314 </dl> 11315 11316 <p> 11317 Sample <a href="postconf.5.html">main.cf</a> setting: 11318 </p> 11319 11320 <pre> 11321 <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> = hostname, nexthop, dot-nexthop 11322 </pre> 11323 11324 <p> 11325 Sample policy table override: 11326 </p> 11327 11328 <pre> 11329 example.com verify match=hostname:nexthop 11330 .example.com verify match=example.com:.example.com:hostname 11331 </pre> 11332 11333 <p> This feature is available in Postfix 2.3 and later. </p> 11334 11335 11336 </DD> 11337 11338 <DT><b><a name="smtp_use_tls">smtp_use_tls</a> 11339 (default: no)</b></DT><DD> 11340 11341 <p> Opportunistic mode: use TLS when a remote SMTP server announces 11342 STARTTLS support, otherwise send the mail in the clear. Beware: 11343 some SMTP servers offer STARTTLS even if it is not configured. With 11344 Postfix < 2.3, if the TLS handshake fails, and no other server is 11345 available, delivery is deferred and mail stays in the queue. If this 11346 is a concern for you, use the <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> feature instead. </p> 11347 11348 <p> This feature is available in Postfix 2.2 and later. With 11349 Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> instead. </p> 11350 11351 11352 </DD> 11353 11354 <DT><b><a name="smtp_xforward_timeout">smtp_xforward_timeout</a> 11355 (default: 300s)</b></DT><DD> 11356 11357 <p> 11358 The SMTP client time limit for sending the XFORWARD command, and 11359 for receiving the server response. 11360 </p> 11361 11362 <p> 11363 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 11364 The default time unit is s (seconds). 11365 </p> 11366 11367 <p> 11368 This feature is available in Postfix 2.1 and later. 11369 </p> 11370 11371 11372 </DD> 11373 11374 <DT><b><a name="smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a> 11375 (default: $<a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a>)</b></DT><DD> 11376 11377 <p> What SMTP clients are allowed to specify the XVERP command. 11378 This command requests that mail be delivered one recipient at a 11379 time with a per recipient return address. </p> 11380 11381 <p> By default, no clients are allowed to specify XVERP. </p> 11382 11383 <p> This parameter was renamed with Postfix version 2.1. The default value 11384 is backwards compatible with Postfix version 2.0. </p> 11385 11386 <p> Specify a list of network/netmask patterns, separated by commas 11387 and/or whitespace. The mask specifies the number of bits in the 11388 network part of a host address. You can also specify hostnames or 11389 .domain names (the initial dot causes the domain to match any name 11390 below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" 11391 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 11392 is matched when a table entry matches a lookup string (the lookup 11393 result is ignored). Continue long lines by starting the next line 11394 with whitespace. Specify "!pattern" to exclude an address or network 11395 block from the list. The form "!/file/name" is supported only in 11396 Postfix version 2.4 and later. </p> 11397 11398 <p> Note: IP version 6 address information must be specified inside 11399 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a> value, and in 11400 files specified with "/file/name". IP version 6 addresses contain 11401 the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 11402 pattern. </p> 11403 11404 11405 </DD> 11406 11407 <DT><b><a name="smtpd_authorized_xclient_hosts">smtpd_authorized_xclient_hosts</a> 11408 (default: empty)</b></DT><DD> 11409 11410 <p> 11411 What SMTP clients are allowed to use the XCLIENT feature. This 11412 command overrides SMTP client information that is used for access 11413 control. Typical use is for SMTP-based content filters, fetchmail-like 11414 programs, or SMTP server access rule testing. See the <a href="XCLIENT_README.html">XCLIENT_README</a> 11415 document for details. 11416 </p> 11417 11418 <p> 11419 This feature is available in Postfix 2.1 and later. 11420 </p> 11421 11422 <p> 11423 By default, no clients are allowed to specify XCLIENT. 11424 </p> 11425 11426 <p> 11427 Specify a list of network/netmask patterns, separated by commas 11428 and/or whitespace. The mask specifies the number of bits in the 11429 network part of a host address. You can also specify hostnames or 11430 .domain names (the initial dot causes the domain to match any name 11431 below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" 11432 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 11433 is matched when a table entry matches a lookup string (the lookup 11434 result is ignored). Continue long lines by starting the next line 11435 with whitespace. Specify "!pattern" to exclude an address or network 11436 block from the list. The form "!/file/name" is supported only in 11437 Postfix version 2.4 and later. </p> 11438 11439 <p> Note: IP version 6 address information must be specified inside 11440 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_authorized_xclient_hosts">smtpd_authorized_xclient_hosts</a> value, and in 11441 files specified with "/file/name". IP version 6 addresses contain 11442 the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 11443 pattern. </p> 11444 11445 11446 </DD> 11447 11448 <DT><b><a name="smtpd_authorized_xforward_hosts">smtpd_authorized_xforward_hosts</a> 11449 (default: empty)</b></DT><DD> 11450 11451 <p> 11452 What SMTP clients are allowed to use the XFORWARD feature. This 11453 command forwards information that is used to improve logging after 11454 SMTP-based content filters. See the <a href="XFORWARD_README.html">XFORWARD_README</a> document for 11455 details. 11456 </p> 11457 11458 <p> 11459 This feature is available in Postfix 2.1 and later. 11460 </p> 11461 11462 <p> 11463 By default, no clients are allowed to specify XFORWARD. 11464 </p> 11465 11466 <p> 11467 Specify a list of network/netmask patterns, separated by commas 11468 and/or whitespace. The mask specifies the number of bits in the 11469 network part of a host address. You can also specify hostnames or 11470 .domain names (the initial dot causes the domain to match any name 11471 below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" 11472 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 11473 is matched when a table entry matches a lookup string (the lookup 11474 result is ignored). Continue long lines by starting the next line 11475 with whitespace. Specify "!pattern" to exclude an address or network 11476 block from the list. The form "!/file/name" is supported only in 11477 Postfix version 2.4 and later. </p> 11478 11479 <p> Note: IP version 6 address information must be specified inside 11480 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_authorized_xforward_hosts">smtpd_authorized_xforward_hosts</a> value, and in 11481 files specified with "/file/name". IP version 6 addresses contain 11482 the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 11483 pattern. </p> 11484 11485 11486 </DD> 11487 11488 <DT><b><a name="smtpd_banner">smtpd_banner</a> 11489 (default: $<a href="postconf.5.html#myhostname">myhostname</a> ESMTP $<a href="postconf.5.html#mail_name">mail_name</a>)</b></DT><DD> 11490 11491 <p> 11492 The text that follows the 220 status code in the SMTP greeting 11493 banner. Some people like to see the mail version advertised. By 11494 default, Postfix shows no version. 11495 </p> 11496 11497 <p> 11498 You MUST specify $<a href="postconf.5.html#myhostname">myhostname</a> at the start of the text. This is 11499 required by the SMTP protocol. 11500 </p> 11501 11502 <p> 11503 Example: 11504 </p> 11505 11506 <pre> 11507 <a href="postconf.5.html#smtpd_banner">smtpd_banner</a> = $<a href="postconf.5.html#myhostname">myhostname</a> ESMTP $<a href="postconf.5.html#mail_name">mail_name</a> ($<a href="postconf.5.html#mail_version">mail_version</a>) 11508 </pre> 11509 11510 11511 </DD> 11512 11513 <DT><b><a name="smtpd_client_connection_count_limit">smtpd_client_connection_count_limit</a> 11514 (default: 50)</b></DT><DD> 11515 11516 <p> 11517 How many simultaneous connections any client is allowed to 11518 make to this service. By default, the limit is set to half 11519 the default process limit value. 11520 </p> 11521 11522 <p> 11523 To disable this feature, specify a limit of 0. 11524 </p> 11525 11526 <p> 11527 WARNING: The purpose of this feature is to limit abuse. It must 11528 not be used to regulate legitimate mail traffic. 11529 </p> 11530 11531 <p> 11532 This feature is available in Postfix 2.2 and later. 11533 </p> 11534 11535 11536 </DD> 11537 11538 <DT><b><a name="smtpd_client_connection_rate_limit">smtpd_client_connection_rate_limit</a> 11539 (default: 0)</b></DT><DD> 11540 11541 <p> 11542 The maximal number of connection attempts any client is allowed to 11543 make to this service per time unit. The time unit is specified 11544 with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter. 11545 </p> 11546 11547 <p> 11548 By default, a client can make as many connections per time unit as 11549 Postfix can accept. 11550 </p> 11551 11552 <p> 11553 To disable this feature, specify a limit of 0. 11554 </p> 11555 11556 <p> 11557 WARNING: The purpose of this feature is to limit abuse. It must 11558 not be used to regulate legitimate mail traffic. 11559 </p> 11560 11561 <p> 11562 This feature is available in Postfix 2.2 and later. 11563 </p> 11564 11565 <p> 11566 Example: 11567 </p> 11568 11569 <pre> 11570 <a href="postconf.5.html#smtpd_client_connection_rate_limit">smtpd_client_connection_rate_limit</a> = 1000 11571 </pre> 11572 11573 11574 </DD> 11575 11576 <DT><b><a name="smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a> 11577 (default: $<a href="postconf.5.html#mynetworks">mynetworks</a>)</b></DT><DD> 11578 11579 <p> 11580 Clients that are excluded from smtpd_client_*_count/rate_limit 11581 restrictions. See the <a href="postconf.5.html#mynetworks">mynetworks</a> parameter 11582 description for the parameter value syntax. 11583 </p> 11584 11585 <p> 11586 By default, clients in trusted networks are excluded. Specify a 11587 list of network blocks, hostnames or .domain names (the initial 11588 dot causes the domain to match any name below it). 11589 </p> 11590 11591 <p> Note: IP version 6 address information must be specified inside 11592 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a> value, and 11593 in files specified with "/file/name". IP version 6 addresses 11594 contain the ":" character, and would otherwise be confused with a 11595 "<a href="DATABASE_README.html">type:table</a>" pattern. </p> 11596 11597 <p> 11598 This feature is available in Postfix 2.2 and later. 11599 </p> 11600 11601 11602 </DD> 11603 11604 <DT><b><a name="smtpd_client_message_rate_limit">smtpd_client_message_rate_limit</a> 11605 (default: 0)</b></DT><DD> 11606 11607 <p> 11608 The maximal number of message delivery requests that any client is 11609 allowed to make to this service per time unit, regardless of whether 11610 or not Postfix actually accepts those messages. The time unit is 11611 specified with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter. 11612 </p> 11613 11614 <p> 11615 By default, a client can send as many message delivery requests 11616 per time unit as Postfix can accept. 11617 </p> 11618 11619 <p> 11620 To disable this feature, specify a limit of 0. 11621 </p> 11622 11623 <p> 11624 WARNING: The purpose of this feature is to limit abuse. It must 11625 not be used to regulate legitimate mail traffic. 11626 </p> 11627 11628 <p> 11629 This feature is available in Postfix 2.2 and later. 11630 </p> 11631 11632 <p> 11633 Example: 11634 </p> 11635 11636 <pre> 11637 <a href="postconf.5.html#smtpd_client_message_rate_limit">smtpd_client_message_rate_limit</a> = 1000 11638 </pre> 11639 11640 11641 </DD> 11642 11643 <DT><b><a name="smtpd_client_new_tls_session_rate_limit">smtpd_client_new_tls_session_rate_limit</a> 11644 (default: 0)</b></DT><DD> 11645 11646 <p> 11647 The maximal number of new (i.e., uncached) TLS sessions that a 11648 remote SMTP client is allowed to negotiate with this service per 11649 time unit. The time unit is specified with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> 11650 configuration parameter. 11651 </p> 11652 11653 <p> 11654 By default, a remote SMTP client can negotiate as many new TLS 11655 sessions per time unit as Postfix can accept. 11656 </p> 11657 11658 <p> 11659 To disable this feature, specify a limit of 0. Otherwise, specify 11660 a limit that is at least the per-client concurrent session limit, 11661 or else legitimate client sessions may be rejected. 11662 </p> 11663 11664 <p> 11665 WARNING: The purpose of this feature is to limit abuse. It must 11666 not be used to regulate legitimate mail traffic. 11667 </p> 11668 11669 <p> 11670 This feature is available in Postfix 2.3 and later. 11671 </p> 11672 11673 <p> 11674 Example: 11675 </p> 11676 11677 <pre> 11678 <a href="postconf.5.html#smtpd_client_new_tls_session_rate_limit">smtpd_client_new_tls_session_rate_limit</a> = 100 11679 </pre> 11680 11681 11682 </DD> 11683 11684 <DT><b><a name="smtpd_client_port_logging">smtpd_client_port_logging</a> 11685 (default: no)</b></DT><DD> 11686 11687 <p> Enable logging of the remote SMTP client port in addition to 11688 the hostname and IP address. The logging format is "host[address]:port". 11689 </p> 11690 11691 <p> This feature is available in Postfix 2.5 and later. </p> 11692 11693 11694 </DD> 11695 11696 <DT><b><a name="smtpd_client_recipient_rate_limit">smtpd_client_recipient_rate_limit</a> 11697 (default: 0)</b></DT><DD> 11698 11699 <p> 11700 The maximal number of recipient addresses that any client is allowed 11701 to send to this service per time unit, regardless of whether or not 11702 Postfix actually accepts those recipients. The time unit is specified 11703 with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter. 11704 </p> 11705 11706 <p> 11707 By default, a client can send as many recipient addresses per time 11708 unit as Postfix can accept. 11709 </p> 11710 11711 <p> 11712 To disable this feature, specify a limit of 0. 11713 </p> 11714 11715 <p> 11716 WARNING: The purpose of this feature is to limit abuse. It must 11717 not be used to regulate legitimate mail traffic. 11718 </p> 11719 11720 <p> 11721 This feature is available in Postfix 2.2 and later. 11722 </p> 11723 11724 <p> 11725 Example: 11726 </p> 11727 11728 <pre> 11729 <a href="postconf.5.html#smtpd_client_recipient_rate_limit">smtpd_client_recipient_rate_limit</a> = 1000 11730 </pre> 11731 11732 11733 </DD> 11734 11735 <DT><b><a name="smtpd_client_restrictions">smtpd_client_restrictions</a> 11736 (default: empty)</b></DT><DD> 11737 11738 <p> 11739 Optional SMTP server access restrictions in the context of a client 11740 SMTP connection request. 11741 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 11742 restriction lists" for a discussion of evaluation context and time. 11743 </p> 11744 11745 <p> 11746 The default is to allow all connection requests. 11747 </p> 11748 11749 <p> 11750 Specify a list of restrictions, separated by commas and/or whitespace. 11751 Continue long lines by starting the next line with whitespace. 11752 Restrictions are applied in the order as specified; the first 11753 restriction that matches wins. 11754 </p> 11755 11756 <p> 11757 The following restrictions are specific to client hostname or 11758 client network address information. 11759 </p> 11760 11761 <dl> 11762 11763 <dt><b><a name="check_ccert_access">check_ccert_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11764 11765 <dd> Use the client certificate fingerprint as lookup key for the 11766 specified <a href="access.5.html">access(5)</a> database; with Postfix version 2.2, also require that 11767 the SMTP client certificate is verified successfully. 11768 The fingerprint digest algorithm is configurable via the 11769 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to 11770 Postfix version 2.5). This feature is available with Postfix version 11771 2.2 and later. </dd> 11772 11773 <dt><b><a name="check_client_access">check_client_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11774 11775 <dd>Search the specified access database for the client hostname, 11776 parent domains, client IP address, or networks obtained by stripping 11777 least significant octets. See the <a href="access.5.html">access(5)</a> manual page for details. </dd> 11778 11779 <dt><b><a name="check_client_mx_access">check_client_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11780 11781 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for the 11782 client hostname, and execute the corresponding action. Note: a result 11783 of "OK" is not allowed for safety reasons. Instead, use DUNNO in order 11784 to exclude specific hosts from blacklists. This feature is available 11785 in Postfix 2.7 and later. </dd> 11786 11787 <dt><b><a name="check_client_ns_access">check_client_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11788 11789 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers for 11790 the client hostname, and execute the corresponding action. Note: a 11791 result of "OK" is not allowed for safety reasons. Instead, use DUNNO 11792 in order to exclude specific hosts from blacklists. This feature is 11793 available in Postfix 2.7 and later. </dd> 11794 11795 <dt><b><a name="check_reverse_client_hostname_access">check_reverse_client_hostname_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11796 11797 <dd>Search the specified access database for the unverified reverse 11798 client hostname, parent domains, client IP address, or networks 11799 obtained by stripping least significant octets. See the <a href="access.5.html">access(5)</a> 11800 manual page for details. Note: a result of "OK" is not allowed for 11801 safety reasons. Instead, use DUNNO in order to exclude specific 11802 hosts from blacklists. This feature is available in Postfix 2.6 11803 and later.</dd> 11804 11805 <dt><b><a name="check_reverse_client_hostname_mx_access">check_reverse_client_hostname_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11806 11807 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for the 11808 unverified reverse client hostname, and execute the corresponding 11809 action. Note: a result of "OK" is not allowed for safety reasons. 11810 Instead, use DUNNO in order to exclude specific hosts from blacklists. 11811 This feature is available in Postfix 2.7 and later. </dd> 11812 11813 <dt><b><a name="check_reverse_client_hostname_ns_access">check_reverse_client_hostname_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11814 11815 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers for 11816 the unverified reverse client hostname, and execute the corresponding 11817 action. Note: a result of "OK" is not allowed for safety reasons. 11818 Instead, use DUNNO in order to exclude specific hosts from blacklists. 11819 This feature is available in Postfix 2.7 and later. </dd> 11820 11821 <dt><b><a name="permit_inet_interfaces">permit_inet_interfaces</a></b></dt> 11822 11823 <dd>Permit the request when the client IP address matches 11824 $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>. </dd> 11825 11826 <dt><b><a name="permit_mynetworks">permit_mynetworks</a></b></dt> 11827 11828 <dd>Permit the request when the client IP address matches any 11829 network or network address listed in $<a href="postconf.5.html#mynetworks">mynetworks</a>. </dd> 11830 11831 <dt><b><a name="permit_sasl_authenticated">permit_sasl_authenticated</a></b></dt> 11832 11833 <dd> Permit the request when the client is successfully 11834 authenticated via the <a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a> (AUTH) protocol. </dd> 11835 11836 <dt><b><a name="permit_tls_all_clientcerts">permit_tls_all_clientcerts</a></b></dt> 11837 11838 <dd> Permit the request when the remote SMTP client certificate is 11839 verified successfully. This option must be used only if a special 11840 CA issues the certificates and only this CA is listed as trusted 11841 CA. Otherwise, clients with a third-party certificate would also 11842 be allowed to relay. Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" when the 11843 trusted CA is specified with <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> or <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>, 11844 to prevent Postfix from appending the system-supplied default CAs. 11845 This feature is available with Postfix version 2.2.</dd> 11846 11847 <dt><b><a name="permit_tls_clientcerts">permit_tls_clientcerts</a></b></dt> 11848 11849 <dd>Permit the request when the remote SMTP client certificate 11850 fingerprint is listed in $<a href="postconf.5.html#relay_clientcerts">relay_clientcerts</a>. 11851 The fingerprint digest algorithm is configurable via the 11852 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to 11853 Postfix version 2.5). This feature is available with Postfix version 11854 2.2. </dd> 11855 11856 <dt><b><a name="reject_rbl_client">reject_rbl_client <i>rbl_domain=d.d.d.d</i></a></b></dt> 11857 11858 <dd>Reject the request when the reversed client network address is 11859 listed with the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> 11860 (Postfix version 2.1 and later only). Each "<i>d</i>" is a number, 11861 or a pattern inside "[]" that contains one or more ";"-separated 11862 numbers or number..number ranges (Postfix version 2.8 and later). 11863 If no "<i>=d.d.d.d</i>" is specified, reject the request when the 11864 reversed client network address is listed with any A record under 11865 <i>rbl_domain</i>. <br> 11866 The <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> parameter specifies the response code for 11867 rejected requests (default: 554), the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> parameter 11868 specifies the default server reply, and the <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> parameter 11869 specifies tables with server replies indexed by <i>rbl_domain</i>. 11870 This feature is available in Postfix 2.0 and later. </dd> 11871 11872 <dt><b><a name="permit_dnswl_client">permit_dnswl_client <i>dnswl_domain=d.d.d.d</i></a></b></dt> 11873 11874 <dd>Accept the request when the reversed client network address is 11875 listed with the A record "<i>d.d.d.d</i>" under <i>dnswl_domain</i>. 11876 Each "<i>d</i>" is a number, or a pattern inside "[]" that contains 11877 one or more ";"-separated numbers or number..number ranges. 11878 If no "<i>=d.d.d.d</i>" is specified, accept the request when the 11879 reversed client network address is listed with any A record under 11880 <i>dnswl_domain</i>. <br> For safety, <a href="postconf.5.html#permit_dnswl_client">permit_dnswl_client</a> is silently 11881 ignored when it would override <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>. The 11882 result is DEFER_IF_REJECT when whitelist lookup fails. This feature 11883 is available in Postfix 2.8 and later. </dd> 11884 11885 <dt><b><a name="reject_rhsbl_client">reject_rhsbl_client <i>rbl_domain=d.d.d.d</i></a></b></dt> 11886 11887 <dd>Reject the request when the client hostname is listed with the 11888 A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> (Postfix version 11889 2.1 and later only). Each "<i>d</i>" is a number, or a pattern 11890 inside "[]" that contains one or more ";"-separated numbers or 11891 number..number ranges (Postfix version 2.8 and later). If no 11892 "<i>=d.d.d.d</i>" is specified, reject the request when the client 11893 hostname is listed with 11894 any A record under <i>rbl_domain</i>. See the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> 11895 description above for additional RBL related configuration parameters. 11896 This feature is available in Postfix 2.0 and later; with Postfix 11897 version 2.8 and later, <a href="postconf.5.html#reject_rhsbl_reverse_client">reject_rhsbl_reverse_client</a> will usually 11898 produce better results. </dd> 11899 11900 <dt><b><a name="permit_rhswl_client">permit_rhswl_client <i>rhswl_domain=d.d.d.d</i></a></b></dt> 11901 11902 <dd>Accept the request when the client hostname is listed with the 11903 A record "<i>d.d.d.d</i>" under <i>rhswl_domain</i>. Each "<i>d</i>" 11904 is a number, or a pattern inside "[]" that contains one or more 11905 ";"-separated numbers or number..number ranges. If no 11906 "<i>=d.d.d.d</i>" is specified, accept the request when the client 11907 hostname is listed with any A record under <i>rhswl_domain</i>. 11908 <br> Caution: client name whitelisting is fragile, since the client 11909 name lookup can fail due to temporary outages. Client name 11910 whitelisting should be used only to reduce false positives in e.g. 11911 DNS-based blocklists, and not for making access rule exceptions. 11912 <br> For safety, <a href="postconf.5.html#permit_rhswl_client">permit_rhswl_client</a> is silently ignored when it 11913 would override <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>. The result is DEFER_IF_REJECT 11914 when whitelist lookup fails. This feature is available in Postfix 11915 2.8 and later. </dd> 11916 11917 <dt><b><a name="reject_rhsbl_reverse_client">reject_rhsbl_reverse_client <i>rbl_domain=d.d.d.d</i></a></b></dt> 11918 11919 <dd>Reject the request when the unverified reverse client hostname 11920 is listed with the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i>. 11921 Each "<i>d</i>" is a number, or a pattern inside "[]" that contains 11922 one or more ";"-separated numbers or number..number ranges. 11923 If no "<i>=d.d.d.d</i>" is specified, reject the request when the 11924 unverified reverse client hostname is listed with any A record under 11925 <i>rbl_domain</i>. See the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> description above for 11926 additional RBL related configuration parameters. This feature is 11927 available in Postfix 2.8 and later. </dd> 11928 11929 <dt><b><a name="reject_unknown_client_hostname">reject_unknown_client_hostname</a></b> (with Postfix < 2.3: reject_unknown_client)</dt> 11930 11931 <dd>Reject the request when 1) the client IP address->name mapping 11932 fails, 2) the name->address mapping fails, or 3) the name->address 11933 mapping does not match the client IP address. <br> This is a 11934 stronger restriction than the <a href="postconf.5.html#reject_unknown_reverse_client_hostname">reject_unknown_reverse_client_hostname</a> 11935 feature, which triggers only under condition 1) above. <br> The 11936 <a href="postconf.5.html#unknown_client_reject_code">unknown_client_reject_code</a> parameter specifies the response code 11937 for rejected requests (default: 450). The reply is always 450 in 11938 case the address->name or name->address lookup failed due to 11939 a temporary problem. </dd> 11940 11941 <dt><b><a name="reject_unknown_reverse_client_hostname">reject_unknown_reverse_client_hostname</a></b></dt> 11942 11943 <dd>Reject the request when the client IP address has no address->name 11944 mapping. <br> This is a weaker restriction than the 11945 <a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> feature, which requires not only 11946 that the address->name and name->address mappings exist, but 11947 also that the two mappings reproduce the client IP address. <br> 11948 The <a href="postconf.5.html#unknown_client_reject_code">unknown_client_reject_code</a> parameter specifies the response 11949 code for rejected requests (default: 450). The reply is always 450 11950 in case the address->name lookup failed due to a temporary 11951 problem. <br> This feature is available in Postfix 2.3 and 11952 later. </dd> 11953 11954 </dl> 11955 11956 <p> 11957 In addition, you can use any of the following <a name="generic"> 11958 generic</a> restrictions. These restrictions are applicable in 11959 any SMTP command context. 11960 </p> 11961 11962 <dl> 11963 11964 <dt><b><a name="check_policy_service">check_policy_service <i>servername</i></a></b></dt> 11965 11966 <dd>Query the specified policy server. See the <a href="SMTPD_POLICY_README.html">SMTPD_POLICY_README</a> 11967 document for details. This feature is available in Postfix 2.1 11968 and later. </dd> 11969 11970 <dt><b><a name="defer">defer</a></b></dt> 11971 11972 <dd>Defer the request. The client is told to try again later. This 11973 restriction is useful at the end of a restriction list, to make 11974 the default policy explicit. <br> The <a href="postconf.5.html#defer_code">defer_code</a> parameter specifies 11975 the SMTP server reply code (default: 450).</dd> 11976 11977 <dt><b><a name="defer_if_permit">defer_if_permit</a></b></dt> 11978 11979 <dd>Defer the request if some later restriction would result in an 11980 explicit or implicit PERMIT action. This is useful when a blacklisting 11981 feature fails due to a temporary problem. This feature is available 11982 in Postfix version 2.1 and later. </dd> 11983 11984 <dt><b><a name="defer_if_reject">defer_if_reject</a></b></dt> 11985 11986 <dd>Defer the request if some later restriction would result in a 11987 REJECT action. This is useful when a whitelisting feature fails 11988 due to a temporary problem. This feature is available in Postfix 11989 version 2.1 and later. </dd> 11990 11991 <dt><b><a name="permit">permit</a></b></dt> 11992 11993 <dd>Permit the request. This restriction is useful at the end of 11994 a restriction list, to make the default policy explicit.</dd> 11995 11996 <dt><b><a name="reject_multi_recipient_bounce">reject_multi_recipient_bounce</a></b></dt> 11997 11998 <dd>Reject the request when the envelope sender is the null address, 11999 and the message has multiple envelope recipients. This usage has 12000 rare but legitimate applications: under certain conditions, 12001 multi-recipient mail that was posted with the DSN option NOTIFY=NEVER 12002 may be forwarded with the null sender address. 12003 <br> Note: this restriction can only work reliably 12004 when used in <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> or 12005 <a href="postconf.5.html#smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a>, because the total number of 12006 recipients is not known at an earlier stage of the SMTP conversation. 12007 Use at the RCPT stage will only reject the second etc. recipient. 12008 <br> 12009 The <a href="postconf.5.html#multi_recipient_bounce_reject_code">multi_recipient_bounce_reject_code</a> parameter specifies the 12010 response code for rejected requests (default: 550). This feature 12011 is available in Postfix 2.1 and later. </dd> 12012 12013 <dt><b><a name="reject_plaintext_session">reject_plaintext_session</a></b></dt> 12014 12015 <dd>Reject the request when the connection is not encrypted. This 12016 restriction should not be used before the client has had a chance 12017 to negotiate encryption with the AUTH or STARTTLS commands. 12018 <br> 12019 The <a href="postconf.5.html#plaintext_reject_code">plaintext_reject_code</a> parameter specifies the response 12020 code for rejected requests (default: 450). This feature is available 12021 in Postfix 2.3 and later. </dd> 12022 12023 <dt><b><a name="reject_unauth_pipelining">reject_unauth_pipelining</a></b></dt> 12024 12025 <dd>Reject the request when the client sends SMTP commands ahead 12026 of time where it is not allowed, or when the client sends SMTP 12027 commands ahead of time without knowing that Postfix actually supports 12028 ESMTP command pipelining. This stops mail from bulk mail software 12029 that improperly uses ESMTP command pipelining in order to speed up 12030 deliveries. 12031 <br> With Postfix 2.6 and later, the SMTP server sets a per-session 12032 flag whenever it detects illegal pipelining, including pipelined 12033 EHLO or HELO commands. The <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> feature simply 12034 tests whether the flag was set at any point in time during the 12035 session. 12036 <br> With older Postfix versions, <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> checks 12037 the current status of the input read queue, and its usage is not 12038 recommended in contexts other than <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a>. </dd> 12039 12040 <dt><b><a name="reject">reject</a></b></dt> 12041 12042 <dd>Reject the request. This restriction is useful at the end of 12043 a restriction list, to make the default policy explicit. The 12044 <a href="postconf.5.html#reject_code">reject_code</a> configuration parameter specifies the response code for 12045 rejected requests (default: 554).</dd> 12046 12047 <dt><b><a name="sleep">sleep <i>seconds</i></a></b></dt> 12048 12049 <dd>Pause for the specified number of seconds and proceed with 12050 the next restriction in the list, if any. This may stop zombie 12051 mail when used as: 12052 <pre> 12053 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 12054 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> = 12055 sleep 1, <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> 12056 <a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = no 12057 </pre> 12058 This feature is available in Postfix 2.3. </dd> 12059 12060 <dt><b><a name="warn_if_reject">warn_if_reject</a></b></dt> 12061 12062 <dd>Change the meaning of the next restriction, so that it logs 12063 a warning instead of rejecting a request (look for logfile records 12064 that contain "reject_warning"). This is useful for testing new 12065 restrictions in a "live" environment without risking unnecessary 12066 loss of mail. </dd> 12067 12068 </dl> 12069 12070 <p> 12071 Other restrictions that are valid in this context: 12072 </p> 12073 12074 <ul> 12075 12076 <li> SMTP command specific restrictions that are described under 12077 the <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>, <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> or 12078 <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> parameters. When helo, sender or 12079 recipient restrictions are listed under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, 12080 they have effect only with "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes", so that 12081 $<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> is evaluated at the time of the RCPT TO 12082 command. 12083 12084 </ul> 12085 12086 <p> 12087 Example: 12088 </p> 12089 12090 <pre> 12091 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> 12092 </pre> 12093 12094 12095 </DD> 12096 12097 <DT><b><a name="smtpd_command_filter">smtpd_command_filter</a> 12098 (default: empty)</b></DT><DD> 12099 12100 <p> A mechanism to transform commands from remote SMTP clients. 12101 This is a last-resort tool to work around client commands that break 12102 inter-operability with the Postfix SMTP server. Other uses involve 12103 fault injection to test Postfix's handling of invalid commands. 12104 </p> 12105 12106 <p> Specify the name of a "<a href="DATABASE_README.html">type:table</a>" lookup table. The search 12107 string is the SMTP command as received from the remote SMTP client, 12108 except that initial whitespace and the trailing <CR><LF> 12109 are removed. The result value is executed by the Postfix SMTP 12110 server. </p> 12111 12112 <p> There is no need to use <a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a> for the following 12113 cases: </p> 12114 12115 <ul> 12116 12117 <li> <p> Use "<a href="postconf.5.html#resolve_numeric_domain">resolve_numeric_domain</a> = yes" to accept 12118 "<i>user@ipaddress</i>". </p> 12119 12120 <li> <p> Postfix already accepts the correct form 12121 "<i>user@[ipaddress]</i>". Use <a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> or <a href="postconf.5.html#canonical_maps">canonical_maps</a> 12122 to translate these into domain names if necessary. </p> 12123 12124 <li> <p> Use "<a href="postconf.5.html#strict_rfc821_envelopes">strict_rfc821_envelopes</a> = no" to accept "RCPT TO:<<i>User 12125 Name <user (a] example.com>></i>". Postfix will ignore the "<i>User 12126 Name</i>" part and deliver to the <i><user (a] example.com></i> address. 12127 </p> 12128 12129 </ul> 12130 12131 <p> Examples of problems that can be solved with the <a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a> 12132 feature: </p> 12133 12134 <pre> 12135 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 12136 <a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a> = <a href="pcre_table.5.html">pcre</a>:/etc/postfix/command_filter 12137 </pre> 12138 12139 <pre> 12140 /etc/postfix/command_filter: 12141 # Work around clients that send malformed HELO commands. 12142 /^HELO\s*$/ HELO domain.invalid 12143 </pre> 12144 12145 <pre> 12146 # Work around clients that send empty lines. 12147 /^\s*$/ NOOP 12148 </pre> 12149 12150 <pre> 12151 # Work around clients that send RCPT TO:<'user@domain'>. 12152 # WARNING: do not lose the parameters that follow the address. 12153 /^RCPT\s+TO:\s*<'([^[:space:]]+)'>(.*)/ RCPT TO:<$1>$2 12154 </pre> 12155 12156 <pre> 12157 # Bounce-never mail sink. Use <a href="postconf.5.html#notify_classes">notify_classes</a>=bounce,resource,software 12158 # to send bounced mail to the postmaster (with message body removed). 12159 /^(RCPT\s+TO:.*?)\bNOTIFY=\S+\b(.*)/ $1 NOTIFY=NEVER $2 12160 /^(RCPT\s+TO:.*)/ $1 NOTIFY=NEVER 12161 </pre> 12162 12163 <p> This feature is available in Postfix 2.7. </p> 12164 12165 12166 </DD> 12167 12168 <DT><b><a name="smtpd_data_restrictions">smtpd_data_restrictions</a> 12169 (default: empty)</b></DT><DD> 12170 12171 <p> 12172 Optional access restrictions that the Postfix SMTP server applies 12173 in the context of the SMTP DATA command. 12174 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 12175 restriction lists" for a discussion of evaluation context and time. 12176 </p> 12177 12178 <p> 12179 This feature is available in Postfix 2.0 and later. 12180 </p> 12181 12182 <p> 12183 Specify a list of restrictions, separated by commas and/or whitespace. 12184 Continue long lines by starting the next line with whitespace. 12185 Restrictions are applied in the order as specified; the first 12186 restriction that matches wins. 12187 </p> 12188 12189 <p> 12190 The following restrictions are valid in this context: 12191 </p> 12192 12193 <ul> 12194 12195 <li><a href="#generic">Generic</a> restrictions that can be used 12196 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 12197 12198 <li>SMTP command specific restrictions described under 12199 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>, 12200 <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> or <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>. 12201 12202 <li>However, no recipient information is available in the case of 12203 multi-recipient mail. Acting on only one recipient would be misleading, 12204 because any decision will affect all recipients equally. Acting on 12205 all recipients would require a possibly very large amount of memory, 12206 and would also be misleading for the reasons mentioned before. 12207 12208 </ul> 12209 12210 <p> 12211 Examples: 12212 </p> 12213 12214 <pre> 12215 <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> = <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> 12216 <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> = <a href="postconf.5.html#reject_multi_recipient_bounce">reject_multi_recipient_bounce</a> 12217 </pre> 12218 12219 12220 </DD> 12221 12222 <DT><b><a name="smtpd_delay_open_until_valid_rcpt">smtpd_delay_open_until_valid_rcpt</a> 12223 (default: yes)</b></DT><DD> 12224 12225 <p> Postpone the start of an SMTP mail transaction until a valid 12226 RCPT TO command is received. Specify "no" to create a mail transaction 12227 as soon as the SMTP server receives a valid MAIL FROM command. </p> 12228 12229 <p> With sites that reject lots of mail, the default setting reduces 12230 the use of 12231 disk, CPU and memory resources. The downside is that rejected 12232 recipients are logged with NOQUEUE instead of a mail transaction 12233 ID. This complicates the logfile analysis of multi-recipient mail. 12234 </p> 12235 12236 <p> This feature is available in Postfix 2.3 and later. </p> 12237 12238 12239 </DD> 12240 12241 <DT><b><a name="smtpd_delay_reject">smtpd_delay_reject</a> 12242 (default: yes)</b></DT><DD> 12243 12244 <p> 12245 Wait until the RCPT TO command before evaluating 12246 $<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, $<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> and 12247 $<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>, or wait until the ETRN command before 12248 evaluating $<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> and $<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>. 12249 </p> 12250 12251 <p> 12252 This feature is turned on by default because some clients apparently 12253 mis-behave when the Postfix SMTP server rejects commands before 12254 RCPT TO. 12255 </p> 12256 12257 <p> 12258 The default setting has one major benefit: it allows Postfix to log 12259 recipient address information when rejecting a client name/address 12260 or sender address, so that it is possible to find out whose mail 12261 is being rejected. 12262 </p> 12263 12264 12265 </DD> 12266 12267 <DT><b><a name="smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a> 12268 (default: empty)</b></DT><DD> 12269 12270 <p> Lookup tables, indexed by the remote SMTP client address, with 12271 case insensitive lists of EHLO keywords (pipelining, starttls, auth, 12272 etc.) that the SMTP server will not send in the EHLO response to a 12273 remote SMTP client. See <a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a> for details. 12274 The table is not searched by hostname for robustness reasons. </p> 12275 12276 <p> This feature is available in Postfix 2.2 and later. </p> 12277 12278 12279 </DD> 12280 12281 <DT><b><a name="smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a> 12282 (default: empty)</b></DT><DD> 12283 12284 <p> A case insensitive list of EHLO keywords (pipelining, starttls, 12285 auth, etc.) that the SMTP server will not send in the EHLO response 12286 to a remote SMTP client. </p> 12287 12288 <p> This feature is available in Postfix 2.2 and later. </p> 12289 12290 <p> Notes: </p> 12291 12292 <ul> 12293 12294 <li> <p> Specify the <b>silent-discard</b> pseudo keyword to prevent 12295 this action from being logged. </p> 12296 12297 <li> <p> Use the <a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a> feature 12298 to discard EHLO keywords selectively. </p> 12299 12300 </ul> 12301 12302 12303 </DD> 12304 12305 <DT><b><a name="smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a> 12306 (default: empty)</b></DT><DD> 12307 12308 <p> Optional access restrictions that the Postfix SMTP server 12309 applies in the context of the SMTP END-OF-DATA command. 12310 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 12311 restriction lists" for a discussion of evaluation context and time. 12312 </p> 12313 12314 <p> This feature is available in Postfix 2.2 and later. </p> 12315 12316 <p> See <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> for details and limitations. </p> 12317 12318 12319 </DD> 12320 12321 <DT><b><a name="smtpd_enforce_tls">smtpd_enforce_tls</a> 12322 (default: no)</b></DT><DD> 12323 12324 <p> Mandatory TLS: announce STARTTLS support to SMTP clients, 12325 and require that clients use TLS encryption. According to <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> 12326 this MUST NOT be applied in case of a publicly-referenced SMTP 12327 server. This option is off by default and should be used only on 12328 dedicated servers. </p> 12329 12330 <p> Note 1: "<a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a> = yes" implies "<a href="postconf.5.html#smtpd_tls_auth_only">smtpd_tls_auth_only</a> = yes". </p> 12331 12332 <p> Note 2: when invoked via "<b>sendmail -bs</b>", Postfix will never offer 12333 STARTTLS due to insufficient privileges to access the server private 12334 key. This is intended behavior. </p> 12335 12336 <p> This feature is available in Postfix 2.2 and later. With 12337 Postfix 2.3 and later use <a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> instead. </p> 12338 12339 12340 </DD> 12341 12342 <DT><b><a name="smtpd_error_sleep_time">smtpd_error_sleep_time</a> 12343 (default: 1s)</b></DT><DD> 12344 12345 <p>With Postfix version 2.1 and later: the SMTP server response delay after 12346 a client has made more than $<a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> errors, and 12347 fewer than $<a href="postconf.5.html#smtpd_hard_error_limit">smtpd_hard_error_limit</a> errors, without delivering mail. 12348 </p> 12349 12350 <p>With Postfix version 2.0 and earlier: the SMTP server delay before 12351 sending a reject (4xx or 5xx) response, when the client has made 12352 fewer than $<a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> errors without delivering 12353 mail. </p> 12354 12355 12356 </DD> 12357 12358 <DT><b><a name="smtpd_etrn_restrictions">smtpd_etrn_restrictions</a> 12359 (default: empty)</b></DT><DD> 12360 12361 <p> 12362 Optional SMTP server access restrictions in the context of a client 12363 ETRN request. 12364 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 12365 restriction lists" for a discussion of evaluation context and time. 12366 </p> 12367 12368 <p> 12369 The Postfix ETRN implementation accepts only destinations that are 12370 eligible for the Postfix "fast flush" service. See the <a href="ETRN_README.html">ETRN_README</a> 12371 file for details. 12372 </p> 12373 12374 <p> 12375 Specify a list of restrictions, separated by commas and/or whitespace. 12376 Continue long lines by starting the next line with whitespace. 12377 Restrictions are applied in the order as specified; the first 12378 restriction that matches wins. 12379 </p> 12380 12381 <p> 12382 The following restrictions are specific to the domain name information 12383 received with the ETRN command. 12384 </p> 12385 12386 <dl> 12387 12388 <dt><b><a name="check_etrn_access">check_etrn_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 12389 12390 <dd>Search the specified access database for the ETRN domain name 12391 or its parent domains. See the <a href="access.5.html">access(5)</a> manual page for details. 12392 </dd> 12393 12394 </dl> 12395 12396 <p> 12397 Other restrictions that are valid in this context: 12398 </p> 12399 12400 <ul> 12401 12402 <li><a href="#generic">Generic</a> restrictions that can be used 12403 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 12404 12405 <li>SMTP command specific restrictions described under 12406 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> and <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>. 12407 12408 </ul> 12409 12410 <p> 12411 Example: 12412 </p> 12413 12414 <pre> 12415 <a href="postconf.5.html#smtpd_etrn_restrictions">smtpd_etrn_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, reject 12416 </pre> 12417 12418 12419 </DD> 12420 12421 <DT><b><a name="smtpd_expansion_filter">smtpd_expansion_filter</a> 12422 (default: see "postconf -d" output)</b></DT><DD> 12423 12424 <p> 12425 What characters are allowed in $name expansions of RBL reply 12426 templates. Characters not in the allowed set are replaced by "_". 12427 Use C like escapes to specify special characters such as whitespace. 12428 </p> 12429 12430 <p> 12431 This parameter is not subjected to $parameter expansion. 12432 </p> 12433 12434 <p> 12435 This feature is available in Postfix 2.0 and later. 12436 </p> 12437 12438 12439 </DD> 12440 12441 <DT><b><a name="smtpd_forbidden_commands">smtpd_forbidden_commands</a> 12442 (default: CONNECT, GET, POST)</b></DT><DD> 12443 12444 <p> 12445 List of commands that cause the Postfix SMTP server to immediately 12446 terminate the session with a 221 code. This can be used to disconnect 12447 clients that obviously attempt to abuse the system. In addition to the 12448 commands listed in this parameter, commands that follow the "Label:" 12449 format of message headers will also cause a disconnect. 12450 </p> 12451 12452 <p> 12453 This feature is available in Postfix 2.2 and later. 12454 </p> 12455 12456 12457 </DD> 12458 12459 <DT><b><a name="smtpd_hard_error_limit">smtpd_hard_error_limit</a> 12460 (default: normal: 20, overload: 1)</b></DT><DD> 12461 12462 <p> 12463 The maximal number of errors a remote SMTP client is allowed to 12464 make without delivering mail. The Postfix SMTP server disconnects 12465 when the limit is exceeded. Normally the default limit is 20, but 12466 it changes under overload to just 1. With Postfix 2.5 and earlier, 12467 the SMTP server always allows up to 20 errors by default. 12468 12469 </p> 12470 12471 12472 </DD> 12473 12474 <DT><b><a name="smtpd_helo_required">smtpd_helo_required</a> 12475 (default: no)</b></DT><DD> 12476 12477 <p> 12478 Require that a remote SMTP client introduces itself with the HELO 12479 or EHLO command before sending the MAIL command or other commands 12480 that require EHLO negotiation. 12481 </p> 12482 12483 <p> 12484 Example: 12485 </p> 12486 12487 <pre> 12488 <a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes 12489 </pre> 12490 12491 12492 </DD> 12493 12494 <DT><b><a name="smtpd_helo_restrictions">smtpd_helo_restrictions</a> 12495 (default: empty)</b></DT><DD> 12496 12497 <p> 12498 Optional restrictions that the Postfix SMTP server applies in the 12499 context of the SMTP HELO command. 12500 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 12501 restriction lists" for a discussion of evaluation context and time. 12502 </p> 12503 12504 <p> 12505 The default is to permit everything. 12506 </p> 12507 12508 <p> Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this 12509 restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can 12510 simply skip <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> by not sending HELO or EHLO). 12511 </p> 12512 12513 <p> 12514 Specify a list of restrictions, separated by commas and/or whitespace. 12515 Continue long lines by starting the next line with whitespace. 12516 Restrictions are applied in the order as specified; the first 12517 restriction that matches wins. 12518 </p> 12519 12520 <p> 12521 The following restrictions are specific to the hostname information 12522 received with the HELO or EHLO command. 12523 </p> 12524 12525 <dl> 12526 12527 <dt><b><a name="check_helo_access">check_helo_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 12528 12529 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the HELO or EHLO 12530 hostname or parent domains, and execute the corresponding action. 12531 Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this 12532 restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can 12533 simply skip <a href="postconf.5.html#check_helo_access">check_helo_access</a> by not sending HELO or EHLO). </dd> 12534 12535 <dt><b><a name="check_helo_mx_access">check_helo_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 12536 12537 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for 12538 the HELO or EHLO hostname, and execute the corresponding action. 12539 Note 1: a result of "OK" is not allowed for safety reasons. Instead, 12540 use DUNNO in order to exclude specific hosts from blacklists. Note 12541 2: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this 12542 restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can 12543 simply skip <a href="postconf.5.html#check_helo_mx_access">check_helo_mx_access</a> by not sending HELO or EHLO). This 12544 feature is available in Postfix 2.1 and later. 12545 </dd> 12546 12547 <dt><b><a name="check_helo_ns_access">check_helo_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 12548 12549 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers 12550 for the HELO or EHLO hostname, and execute the corresponding action. 12551 Note 1: a result of "OK" is not allowed for safety reasons. Instead, 12552 use DUNNO in order to exclude specific hosts from blacklists. Note 12553 2: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this 12554 restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can 12555 simply skip <a href="postconf.5.html#check_helo_ns_access">check_helo_ns_access</a> by not sending HELO or EHLO). This 12556 feature is available in Postfix 2.1 and later. 12557 </dd> 12558 12559 <dt><b><a name="reject_invalid_helo_hostname">reject_invalid_helo_hostname</a></b> (with Postfix < 2.3: reject_invalid_hostname)</dt> 12560 12561 <dd>Reject the request when the HELO or EHLO hostname syntax is 12562 invalid. Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce 12563 this restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can simply 12564 skip <a href="postconf.5.html#reject_invalid_helo_hostname">reject_invalid_helo_hostname</a> by not sending HELO or EHLO). 12565 <br> The <a href="postconf.5.html#invalid_hostname_reject_code">invalid_hostname_reject_code</a> specifies the response code 12566 for rejected requests (default: 501).</dd> 12567 12568 <dt><b><a name="reject_non_fqdn_helo_hostname">reject_non_fqdn_helo_hostname</a></b> (with Postfix < 2.3: reject_non_fqdn_hostname)</dt> 12569 12570 <dd>Reject the request when the HELO or EHLO hostname is not in 12571 fully-qualified domain form, as required by the RFC. Note: specify 12572 "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this restriction 12573 (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can simply skip 12574 <a href="postconf.5.html#reject_non_fqdn_helo_hostname">reject_non_fqdn_helo_hostname</a> by not sending HELO or EHLO). <br> 12575 The <a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> parameter specifies the response code for 12576 rejected requests (default: 504).</dd> 12577 12578 <dt><b><a name="reject_rhsbl_helo">reject_rhsbl_helo <i>rbl_domain=d.d.d.d</i></a></b></dt> 12579 12580 <dd>Reject the request when the HELO or EHLO hostname hostname is 12581 listed with the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> 12582 (Postfix version 2.1 and later only). Each "<i>d</i>" is a number, 12583 or a pattern inside "[]" that contains one or more ";"-separated 12584 numbers or number..number ranges (Postfix version 2.8 and later). 12585 If no "<i>=d.d.d.d</i>" is 12586 specified, reject the request when the HELO or EHLO hostname is 12587 listed with any A record under <i>rbl_domain</i>. See the 12588 <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> description for additional RBL related configuration 12589 parameters. Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully 12590 enforce this restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a 12591 client can simply skip <a href="postconf.5.html#reject_rhsbl_helo">reject_rhsbl_helo</a> by not sending HELO or 12592 EHLO). This feature is available in Postfix 2.0 12593 and later. </dd> 12594 12595 <dt><b><a name="reject_unknown_helo_hostname">reject_unknown_helo_hostname</a></b> (with Postfix < 2.3: reject_unknown_hostname)</dt> 12596 12597 <dd>Reject the request when the HELO or EHLO hostname has no DNS A 12598 or MX record. <br> The <a href="postconf.5.html#unknown_hostname_reject_code">unknown_hostname_reject_code</a> parameter 12599 specifies the numerical response code for rejected requests (default: 12600 450). <br> The <a href="postconf.5.html#unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a> parameter 12601 specifies the action after a temporary DNS error (default: 12602 <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully 12603 enforce this restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a 12604 client can simply skip <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> by not sending 12605 HELO or EHLO). </dd> 12606 12607 </dl> 12608 12609 <p> 12610 Other restrictions that are valid in this context: 12611 </p> 12612 12613 <ul> 12614 12615 <li> <a href="#generic">Generic</a> restrictions that can be used 12616 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 12617 12618 <li> Client hostname or network address specific restrictions 12619 described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 12620 12621 <li> SMTP command specific restrictions described under 12622 <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> or <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>. When 12623 sender or recipient restrictions are listed under <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>, 12624 they have effect only with "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes", so that 12625 $<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> is evaluated at the time of the RCPT TO 12626 command. 12627 12628 </ul> 12629 12630 <p> 12631 Examples: 12632 </p> 12633 12634 <pre> 12635 <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#reject_invalid_helo_hostname">reject_invalid_helo_hostname</a> 12636 <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> 12637 </pre> 12638 12639 12640 </DD> 12641 12642 <DT><b><a name="smtpd_history_flush_threshold">smtpd_history_flush_threshold</a> 12643 (default: 100)</b></DT><DD> 12644 12645 <p> 12646 The maximal number of lines in the Postfix SMTP server command history 12647 before it is flushed upon receipt of EHLO, RSET, or end of DATA. 12648 </p> 12649 12650 12651 </DD> 12652 12653 <DT><b><a name="smtpd_junk_command_limit">smtpd_junk_command_limit</a> 12654 (default: normal: 100, overload: 1)</b></DT><DD> 12655 12656 <p> 12657 The number of junk commands (NOOP, VRFY, ETRN or RSET) that a remote 12658 SMTP client can send before the Postfix SMTP server starts to 12659 increment the error counter with each junk command. The junk 12660 command count is reset after mail is delivered. See also the 12661 <a href="postconf.5.html#smtpd_error_sleep_time">smtpd_error_sleep_time</a> and <a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> configuration 12662 parameters. Normally the default limit is 100, but it changes under 12663 overload to just 1. With Postfix 2.5 and earlier, the SMTP server 12664 always allows up to 100 junk commands by default. </p> 12665 12666 12667 </DD> 12668 12669 <DT><b><a name="smtpd_milters">smtpd_milters</a> 12670 (default: empty)</b></DT><DD> 12671 12672 <p> A list of Milter (mail filter) applications for new mail that 12673 arrives via the Postfix <a href="smtpd.8.html">smtpd(8)</a> server. See the <a href="MILTER_README.html">MILTER_README</a> 12674 document for details. </p> 12675 12676 <p> This feature is available in Postfix 2.3 and later. </p> 12677 12678 12679 </DD> 12680 12681 <DT><b><a name="smtpd_noop_commands">smtpd_noop_commands</a> 12682 (default: empty)</b></DT><DD> 12683 12684 <p> 12685 List of commands that the Postfix SMTP server replies to with "250 12686 Ok", without doing any syntax checks and without changing state. 12687 This list overrides any commands built into the Postfix SMTP server. 12688 </p> 12689 12690 12691 </DD> 12692 12693 <DT><b><a name="smtpd_null_access_lookup_key">smtpd_null_access_lookup_key</a> 12694 (default: <>)</b></DT><DD> 12695 12696 <p> 12697 The lookup key to be used in SMTP <a href="access.5.html">access(5)</a> tables instead of the 12698 null sender address. 12699 </p> 12700 12701 12702 </DD> 12703 12704 <DT><b><a name="smtpd_peername_lookup">smtpd_peername_lookup</a> 12705 (default: yes)</b></DT><DD> 12706 12707 <p> Attempt to look up the remote SMTP client hostname, and verify that 12708 the name matches the client IP address. A client name is set to 12709 "unknown" when it cannot be looked up or verified, or when name 12710 lookup is disabled. Turning off name lookup reduces delays due to 12711 DNS lookup and increases the maximal inbound delivery rate. </p> 12712 12713 <p> This feature is available in Postfix 2.3 and later. </p> 12714 12715 12716 </DD> 12717 12718 <DT><b><a name="smtpd_policy_service_max_idle">smtpd_policy_service_max_idle</a> 12719 (default: 300s)</b></DT><DD> 12720 12721 <p> 12722 The time after which an idle SMTPD policy service connection is 12723 closed. 12724 </p> 12725 12726 <p> 12727 This feature is available in Postfix 2.1 and later. 12728 </p> 12729 12730 12731 </DD> 12732 12733 <DT><b><a name="smtpd_policy_service_max_ttl">smtpd_policy_service_max_ttl</a> 12734 (default: 1000s)</b></DT><DD> 12735 12736 <p> 12737 The time after which an active SMTPD policy service connection is 12738 closed. 12739 </p> 12740 12741 <p> 12742 This feature is available in Postfix 2.1 and later. 12743 </p> 12744 12745 12746 </DD> 12747 12748 <DT><b><a name="smtpd_policy_service_timeout">smtpd_policy_service_timeout</a> 12749 (default: 100s)</b></DT><DD> 12750 12751 <p> 12752 The time limit for connecting to, writing to or receiving from a 12753 delegated SMTPD policy server. 12754 </p> 12755 12756 <p> 12757 This feature is available in Postfix 2.1 and later. 12758 </p> 12759 12760 12761 </DD> 12762 12763 <DT><b><a name="smtpd_proxy_ehlo">smtpd_proxy_ehlo</a> 12764 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 12765 12766 <p> 12767 How the Postfix SMTP server announces itself to the proxy filter. 12768 By default, the Postfix hostname is used. 12769 </p> 12770 12771 <p> 12772 This feature is available in Postfix 2.1 and later. 12773 </p> 12774 12775 12776 </DD> 12777 12778 <DT><b><a name="smtpd_proxy_filter">smtpd_proxy_filter</a> 12779 (default: empty)</b></DT><DD> 12780 12781 <p> The hostname and TCP port of the mail filtering proxy server. 12782 The proxy receives all mail from the Postfix SMTP server, and is 12783 supposed to give the result to another Postfix SMTP server process. 12784 </p> 12785 12786 <p> Specify "host:port" or "inet:host:port" for a TCP endpoint, or 12787 "unix:pathname" for a UNIX-domain endpoint. The host can be specified 12788 as an IP address or as a symbolic name; no MX lookups are done. 12789 When no "host" or "host:" are specified, the local machine is 12790 assumed. Pathname interpretation is relative to the Postfix queue 12791 directory. </p> 12792 12793 <p> This feature is available in Postfix 2.1 and later. </p> 12794 12795 <p> The "inet:" and "unix:" prefixes are available in Postfix 2.3 12796 and later. </p> 12797 12798 12799 </DD> 12800 12801 <DT><b><a name="smtpd_proxy_options">smtpd_proxy_options</a> 12802 (default: empty)</b></DT><DD> 12803 12804 <p> 12805 List of options that control how the Postfix SMTP server 12806 communicates with a before-queue content filter. Specify zero or 12807 more of the following, separated by comma or whitespace. </p> 12808 12809 <dl> 12810 12811 <dt><b>speed_adjust</b></dt> 12812 12813 <dd> <p> Do not connect to a before-queue content filter until an entire 12814 message has been received. This reduces the number of simultaneous 12815 before-queue content filter processes. </p> 12816 12817 <p> NOTE 1: A filter must not <i>selectively</i> reject recipients 12818 of a multi-recipient message. Rejecting all recipients is OK, as 12819 is accepting all recipients. </p> 12820 12821 <p> NOTE 2: This feature increases the minimum amount of free queue 12822 space by $<a href="postconf.5.html#message_size_limit">message_size_limit</a>. The extra space is needed to save the 12823 message to a temporary file. </p> </dd> 12824 12825 </dl> 12826 12827 <p> 12828 This feature is available in Postfix 2.7 and later. 12829 </p> 12830 12831 12832 </DD> 12833 12834 <DT><b><a name="smtpd_proxy_timeout">smtpd_proxy_timeout</a> 12835 (default: 100s)</b></DT><DD> 12836 12837 <p> 12838 The time limit for connecting to a proxy filter and for sending or 12839 receiving information. When a connection fails the client gets a 12840 generic error message while more detailed information is logged to 12841 the maillog file. 12842 </p> 12843 12844 <p> 12845 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 12846 The default time unit is s (seconds). 12847 </p> 12848 12849 <p> 12850 This feature is available in Postfix 2.1 and later. 12851 </p> 12852 12853 12854 </DD> 12855 12856 <DT><b><a name="smtpd_recipient_limit">smtpd_recipient_limit</a> 12857 (default: 1000)</b></DT><DD> 12858 12859 <p> 12860 The maximal number of recipients that the Postfix SMTP server 12861 accepts per message delivery request. 12862 </p> 12863 12864 12865 </DD> 12866 12867 <DT><b><a name="smtpd_recipient_overshoot_limit">smtpd_recipient_overshoot_limit</a> 12868 (default: 1000)</b></DT><DD> 12869 12870 <p> The number of recipients that a remote SMTP client can send in 12871 excess of the limit specified with $<a href="postconf.5.html#smtpd_recipient_limit">smtpd_recipient_limit</a>, before 12872 the Postfix SMTP server increments the per-session error count 12873 for each excess recipient. </p> 12874 12875 12876 </DD> 12877 12878 <DT><b><a name="smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> 12879 (default: <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>)</b></DT><DD> 12880 12881 <p> 12882 The access restrictions that the Postfix SMTP server applies in 12883 the context of the RCPT TO command. 12884 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 12885 restriction lists" for a discussion of evaluation context and time. 12886 </p> 12887 12888 <p> 12889 By default, the Postfix SMTP server accepts: 12890 </p> 12891 12892 <ul> 12893 12894 <li> Mail from clients whose IP address matches $<a href="postconf.5.html#mynetworks">mynetworks</a>, or: 12895 12896 <li> Mail to remote destinations that match $<a href="postconf.5.html#relay_domains">relay_domains</a>, except 12897 for addresses that contain sender-specified routing 12898 (user@elsewhere@domain), or: 12899 12900 <li> Mail to local destinations that match $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> 12901 or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, or 12902 $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. 12903 12904 </ul> 12905 12906 <p> 12907 IMPORTANT: If you change this parameter setting, you must specify 12908 at least one of the following restrictions. Otherwise Postfix will 12909 refuse to receive mail: 12910 </p> 12911 12912 <blockquote> 12913 <pre> 12914 reject, defer, <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>, <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> 12915 </pre> 12916 </blockquote> 12917 12918 <p> 12919 Specify a list of restrictions, separated by commas and/or whitespace. 12920 Continue long lines by starting the next line with whitespace. 12921 Restrictions are applied in the order as specified; the first 12922 restriction that matches wins. 12923 </p> 12924 12925 <p> 12926 The following restrictions are specific to the recipient address 12927 that is received with the RCPT TO command. 12928 </p> 12929 12930 <dl> 12931 12932 <dt><b><a name="check_recipient_access">check_recipient_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 12933 12934 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the resolved RCPT 12935 TO address, domain, parent domains, or localpart@, and execute the 12936 corresponding action. </dd> 12937 12938 <dt><b><a name="check_recipient_mx_access">check_recipient_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 12939 12940 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for 12941 the RCPT TO domain, and execute the corresponding action. Note: 12942 a result of "OK" is not allowed for safety reasons. Instead, use 12943 DUNNO in order to exclude specific hosts from blacklists. This 12944 feature is available in Postfix 2.1 and later. </dd> 12945 12946 <dt><b><a name="check_recipient_ns_access">check_recipient_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 12947 12948 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers 12949 for the RCPT TO domain, and execute the corresponding action. 12950 Note: a result of "OK" is not allowed for safety reasons. Instead, 12951 use DUNNO in order to exclude specific hosts from blacklists. This 12952 feature is available in Postfix 2.1 and later. </dd> 12953 12954 <dt><b><a name="permit_auth_destination">permit_auth_destination</a></b></dt> 12955 12956 <dd>Permit the request when one of the following is true: 12957 12958 <ul> 12959 12960 <li> Postfix is mail forwarder: the resolved RCPT TO domain matches 12961 $<a href="postconf.5.html#relay_domains">relay_domains</a> or a subdomain thereof, and the address contains no 12962 sender-specified routing (user@elsewhere@domain), 12963 12964 <li> Postfix is the final destination: the resolved RCPT TO domain 12965 matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>, $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, 12966 $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, or $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>, and the address 12967 contains no sender-specified routing (user@elsewhere@domain). 12968 12969 </ul></dd> 12970 12971 <dt><b><a name="permit_mx_backup">permit_mx_backup</a></b></dt> 12972 12973 <dd>Permit the request when the local mail system is backup MX for 12974 the RCPT TO domain, or when the domain is an authorized destination 12975 (see <a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a> for definition). 12976 12977 <ul> 12978 12979 <li> Safety: <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> does not accept addresses that have 12980 sender-specified routing information (example: user@elsewhere@domain). 12981 12982 <li> Safety: <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> can be vulnerable to mis-use when 12983 access is not restricted with <a href="postconf.5.html#permit_mx_backup_networks">permit_mx_backup_networks</a>. 12984 12985 <li> Safety: as of Postfix version 2.3, <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> no longer 12986 accepts the address when the local mail system is primary MX for 12987 the recipient domain. Exception: <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> accepts the address 12988 when it specifies an authorized destination (see <a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a> 12989 for definition). 12990 12991 <li> Limitation: mail may be rejected in case of a temporary DNS 12992 lookup problem with Postfix prior to version 2.0. 12993 12994 </ul></dd> 12995 12996 <dt><b><a name="reject_non_fqdn_recipient">reject_non_fqdn_recipient</a></b></dt> 12997 12998 <dd>Reject the request when the RCPT TO address is not in 12999 fully-qualified domain form, as required by the RFC. <br> The 13000 <a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> parameter specifies the response code for 13001 rejected requests (default: 504). </dd> 13002 13003 <dt><b><a name="reject_rhsbl_recipient">reject_rhsbl_recipient <i>rbl_domain=d.d.d.d</i></a></b></dt> 13004 13005 <dd>Reject the request when the RCPT TO domain is listed with the 13006 A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> (Postfix version 13007 2.1 and later only). Each "<i>d</i>" is a number, or a pattern 13008 inside "[]" that contains one or more ";"-separated numbers or 13009 number..number ranges (Postfix version 2.8 and later). If no 13010 "<i>=d.d.d.d</i>" is specified, reject 13011 the request when the RCPT TO domain is listed with 13012 any A record under <i>rbl_domain</i>. <br> The <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> 13013 parameter specifies the response code for rejected requests (default: 13014 554); the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> parameter specifies the default server 13015 reply; and the <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> parameter specifies tables with server 13016 replies indexed by <i>rbl_domain</i>. This feature is available 13017 in Postfix version 2.0 and later.</dd> 13018 13019 <dt><b><a name="reject_unauth_destination">reject_unauth_destination</a></b></dt> 13020 13021 <dd>Reject the request unless one of the following is true: 13022 13023 <ul> 13024 13025 <li> Postfix is mail forwarder: the resolved RCPT TO domain matches 13026 $<a href="postconf.5.html#relay_domains">relay_domains</a> or a subdomain thereof, and contains no sender-specified 13027 routing (user@elsewhere@domain), 13028 13029 <li> Postfix is the final destination: the resolved RCPT TO domain 13030 matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>, $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, 13031 $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, or $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>, and contains 13032 no sender-specified routing (user@elsewhere@domain). 13033 13034 </ul> The <a href="postconf.5.html#relay_domains_reject_code">relay_domains_reject_code</a> parameter specifies the response 13035 code for rejected requests (default: 554). </dd> 13036 13037 <dt><b><a name="reject_unknown_recipient_domain">reject_unknown_recipient_domain</a></b></dt> 13038 13039 <dd>Reject the request when Postfix is not final destination for 13040 the recipient domain, and the RCPT TO domain has no DNS A or MX 13041 record, or when it has a malformed MX record such as a record with 13042 a zero-length MX hostname (Postfix version 2.3 and later). <br> The 13043 <a href="postconf.5.html#unknown_address_reject_code">unknown_address_reject_code</a> parameter specifies the numerical 13044 response code for rejected requests (default: 450). The response 13045 is always 450 in case of a temporary DNS error. <br> The 13046 <a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a> parameter specifies the action 13047 after a temporary DNS error (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). </dd> 13048 13049 <dt><b><a name="reject_unlisted_recipient">reject_unlisted_recipient</a></b> (with Postfix version 2.0: check_recipient_maps)</dt> 13050 13051 <dd> Reject the request when the RCPT TO address is not listed in 13052 the list of valid recipients for its domain class. See the 13053 <a href="postconf.5.html#smtpd_reject_unlisted_recipient">smtpd_reject_unlisted_recipient</a> parameter description for details. 13054 This feature is available in Postfix 2.1 and later.</dd> 13055 13056 <dt><b><a name="reject_unverified_recipient">reject_unverified_recipient</a></b></dt> 13057 13058 <dd>Reject the request when mail to the RCPT TO address is known 13059 to bounce, or when the recipient address destination is not reachable. 13060 Address verification information is managed by the <a href="verify.8.html">verify(8)</a> server; 13061 see the <a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VERIFICATION_README</a> file for details. <br> The 13062 <a href="postconf.5.html#unverified_recipient_reject_code">unverified_recipient_reject_code</a> parameter specifies the numerical 13063 response code when an address is known to bounce (default: 450, 13064 change into 550 when you are confident that it is safe to do so). 13065 <br>The <a href="postconf.5.html#unverified_recipient_defer_code">unverified_recipient_defer_code</a> parameter specifies the 13066 numerical response code when an address probe failed due to a 13067 temporary problem (default: 450). <br> The 13068 <a href="postconf.5.html#unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a> parameter specifies the action 13069 after addres probe failure due to a temporary problem (default: 13070 <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). <br> This feature is available in Postfix 2.1 13071 and later. </dd> 13072 13073 </dl> 13074 13075 <p> 13076 Other restrictions that are valid in this context: 13077 </p> 13078 13079 <ul> 13080 13081 <li><a href="#generic">Generic</a> restrictions that can be used 13082 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 13083 13084 <li>SMTP command specific restrictions described under 13085 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> and 13086 <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>. 13087 13088 </ul> 13089 13090 <p> 13091 Example: 13092 </p> 13093 13094 <pre> 13095 <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> 13096 </pre> 13097 13098 13099 </DD> 13100 13101 <DT><b><a name="smtpd_reject_footer">smtpd_reject_footer</a> 13102 (default: empty)</b></DT><DD> 13103 13104 <p> Optional information that is appended after each SMTP server 13105 4XX or 5XX response. </p> 13106 13107 <p> Example: </p> 13108 13109 <pre> 13110 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 13111 <a href="postconf.5.html#smtpd_reject_footer">smtpd_reject_footer</a> = For assistance, call 800-555-0101. 13112 Please provide the following information in your problem report: 13113 time ($localtime), client ($client_address) and server 13114 ($server_name). 13115 </pre> 13116 13117 <p> Server response: </p> 13118 13119 <pre> 13120 550-5.5.1 <user@example> Recipient address rejected: User unknown 13121 550 5.5.1 For assistance, call 800-555-0101. Please provide the 13122 following information in your problem report: time (Jan 4 15:42:00), 13123 client (192.168.1.248) and server (mail1.example.com). 13124 </pre> 13125 13126 <p> Note: the above text is meant to make it easier to find the 13127 Postfix logfile records for a failed SMTP session. The text itself 13128 is not logged to the Postfix SMTP server's maillog file. </p> 13129 13130 <p> Be sure to keep the text as short as possible. Long text may 13131 be truncated before it is logged to the remote SMTP client's maillog 13132 file, or before it is returned to the sender in a delivery status 13133 notification. </p> 13134 13135 <p> This feature supports a limited number of $name attributes in 13136 the footer text. These are replaced by their current value for the 13137 SMTP session: </p> 13138 13139 <dl> 13140 13141 <dt> <b>client_address</b> </dt> <dd> The Client IP address that 13142 is logged in the maillog file. </dd> 13143 13144 <dt> <b>client_port</b> </dt> <dd> The client TCP port that is 13145 logged in the maillog file. </dd> 13146 13147 <dt> <b>localtime</b> </dt> <dd> The server local time (Mmm dd 13148 hh:mm:ss) that is logged in the maillog file. </dd> 13149 13150 <dt> <b>server_name</b> </dt> <dd> The server's <a href="postconf.5.html#myhostname">myhostname</a> value. 13151 This attribute is made available for sites with multiple MTAs 13152 (perhaps behind a load-balancer), where the server name can help 13153 the server support team to quickly find the right log files. </dd> 13154 13155 </dl> 13156 13157 <p> Notes: </p> 13158 13159 <ul> 13160 13161 <li> <p> NOT SUPPORTED are other attributes such as sender, recipient, 13162 or <a href="postconf.5.html">main.cf</a> parameters. </p> 13163 13164 <li> <p> For safety reasons, text that does not match 13165 $<a href="postconf.5.html#smtpd_expansion_filter">smtpd_expansion_filter</a> is censored. </p> 13166 13167 </ul> 13168 13169 <p> This feature supports the two-character sequence \n as a request 13170 for a line break in the footer text. Postfix automatically inserts 13171 after each line break the three-digit SMTP reply code (and optional 13172 enhanced status code) from the original Postfix reject message. 13173 </p> 13174 13175 <p> This feature is available in Postfix 2.8 and later. </p> 13176 13177 13178 </DD> 13179 13180 <DT><b><a name="smtpd_reject_unlisted_recipient">smtpd_reject_unlisted_recipient</a> 13181 (default: yes)</b></DT><DD> 13182 13183 <p> 13184 Request that the Postfix SMTP server rejects mail for unknown 13185 recipient addresses, even when no explicit <a href="postconf.5.html#reject_unlisted_recipient">reject_unlisted_recipient</a> 13186 access restriction is specified. This prevents the Postfix queue 13187 from filling up with undeliverable MAILER-DAEMON messages. 13188 </p> 13189 13190 <p> An address is always considered "known" when it matches a 13191 <a href="virtual.5.html">virtual(5)</a> alias or a <a href="canonical.5.html">canonical(5)</a> mapping. 13192 13193 <ul> 13194 13195 <li> The recipient domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> 13196 or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, but the recipient is not listed in 13197 $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a>, and $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> is not null. 13198 13199 <li> The recipient domain matches $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> but the 13200 recipient is not listed in $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>. 13201 13202 <li> The recipient domain matches $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a> but the 13203 recipient is not listed in $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>, and $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> 13204 is not null. 13205 13206 <li> The recipient domain matches $<a href="postconf.5.html#relay_domains">relay_domains</a> but the recipient 13207 is not listed in $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a>, and $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> 13208 is not null. 13209 13210 </ul> 13211 13212 <p> 13213 This feature is available in Postfix 2.1 and later. 13214 </p> 13215 13216 13217 </DD> 13218 13219 <DT><b><a name="smtpd_reject_unlisted_sender">smtpd_reject_unlisted_sender</a> 13220 (default: no)</b></DT><DD> 13221 13222 <p> Request that the Postfix SMTP server rejects mail from unknown 13223 sender addresses, even when no explicit <a href="postconf.5.html#reject_unlisted_sender">reject_unlisted_sender</a> 13224 access restriction is specified. This can slow down an explosion 13225 of forged mail from worms or viruses. </p> 13226 13227 <p> An address is always considered "known" when it matches a 13228 <a href="virtual.5.html">virtual(5)</a> alias or a <a href="canonical.5.html">canonical(5)</a> mapping. 13229 13230 <ul> 13231 13232 <li> The sender domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or 13233 $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, but the sender is not listed in 13234 $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a>, and $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> is not null. 13235 13236 <li> The sender domain matches $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> but the sender 13237 is not listed in $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>. 13238 13239 <li> The sender domain matches $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a> but the 13240 sender is not listed in $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>, and $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> 13241 is not null. 13242 13243 <li> The sender domain matches $<a href="postconf.5.html#relay_domains">relay_domains</a> but the sender is 13244 not listed in $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a>, and $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> is 13245 not null. 13246 13247 </ul> 13248 13249 <p> 13250 This feature is available in Postfix 2.1 and later. 13251 </p> 13252 13253 13254 </DD> 13255 13256 <DT><b><a name="smtpd_restriction_classes">smtpd_restriction_classes</a> 13257 (default: empty)</b></DT><DD> 13258 13259 <p> 13260 User-defined aliases for groups of access restrictions. The aliases 13261 can be specified in <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> etc., and on the 13262 right-hand side of a Postfix <a href="access.5.html">access(5)</a> table. 13263 </p> 13264 13265 <p> 13266 One major application is for implementing per-recipient UCE control. 13267 See the <a href="RESTRICTION_CLASS_README.html">RESTRICTION_CLASS_README</a> document for other examples. 13268 </p> 13269 13270 13271 </DD> 13272 13273 <DT><b><a name="smtpd_sasl_application_name">smtpd_sasl_application_name</a> 13274 (default: smtpd)</b></DT><DD> 13275 13276 <p> 13277 The application name that the Postfix SMTP server uses for SASL 13278 server initialization. This 13279 controls the name of the SASL configuration file. The default value 13280 is <b>smtpd</b>, corresponding to a SASL configuration file named 13281 <b>smtpd.conf</b>. 13282 </p> 13283 13284 <p> 13285 This feature is available in Postfix 2.1 and 2.2. With Postfix 2.3 13286 it was renamed to <a href="postconf.5.html#smtpd_sasl_path">smtpd_sasl_path</a>. 13287 </p> 13288 13289 13290 </DD> 13291 13292 <DT><b><a name="smtpd_sasl_auth_enable">smtpd_sasl_auth_enable</a> 13293 (default: no)</b></DT><DD> 13294 13295 <p> 13296 Enable SASL authentication in the Postfix SMTP server. By default, 13297 the Postfix SMTP server does not use authentication. 13298 </p> 13299 13300 <p> 13301 If a remote SMTP client is authenticated, the <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a> 13302 access restriction can be used to permit relay access, like this: 13303 </p> 13304 13305 <blockquote> 13306 <pre> 13307 <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> = 13308 <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a>, ... 13309 </pre> 13310 </blockquote> 13311 13312 <p> To reject all SMTP connections from unauthenticated clients, 13313 specify "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes" (which is the default) and use: 13314 </p> 13315 13316 <blockquote> 13317 <pre> 13318 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> = <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a>, reject 13319 </pre> 13320 </blockquote> 13321 13322 <p> 13323 See the <a href="SASL_README.html">SASL_README</a> file for SASL configuration and operation details. 13324 </p> 13325 13326 13327 </DD> 13328 13329 <DT><b><a name="smtpd_sasl_authenticated_header">smtpd_sasl_authenticated_header</a> 13330 (default: no)</b></DT><DD> 13331 13332 <p> Report the SASL authenticated user name in the <a href="smtpd.8.html">smtpd(8)</a> Received 13333 message header. </p> 13334 13335 <p> This feature is available in Postfix 2.3 and later. </p> 13336 13337 13338 </DD> 13339 13340 <DT><b><a name="smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> 13341 (default: empty)</b></DT><DD> 13342 13343 <p> 13344 What remote SMTP clients the Postfix SMTP server will not offer 13345 AUTH support to. 13346 </p> 13347 13348 <p> 13349 Some clients (Netscape 4 at least) have a bug that causes them to 13350 require a login and password whenever AUTH is offered, whether it's 13351 necessary or not. To work around this, specify, for example, 13352 $<a href="postconf.5.html#mynetworks">mynetworks</a> to prevent Postfix from offering AUTH to local clients. 13353 </p> 13354 13355 <p> 13356 Specify a list of network/netmask patterns, separated by commas 13357 and/or whitespace. The mask specifies the number of bits in the 13358 network part of a host address. You can also "/file/name" or 13359 "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" pattern is replaced by its 13360 contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a table entry 13361 matches a lookup string (the lookup result is ignored). Continue 13362 long lines by starting the next line with whitespace. Specify 13363 "!pattern" to exclude an address or network block from the list. 13364 The form "!/file/name" is supported only in Postfix version 2.4 and 13365 later. </p> 13366 13367 <p> Note: IP version 6 address information must be specified inside 13368 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> value, and in 13369 files specified with "/file/name". IP version 6 addresses contain 13370 the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 13371 pattern. </p> 13372 13373 <p> 13374 Example: 13375 </p> 13376 13377 <pre> 13378 <a href="postconf.5.html#smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> = $<a href="postconf.5.html#mynetworks">mynetworks</a> 13379 </pre> 13380 13381 <p> 13382 This feature is available in Postfix 2.1 and later. 13383 </p> 13384 13385 13386 </DD> 13387 13388 <DT><b><a name="smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> 13389 (default: empty)</b></DT><DD> 13390 13391 <p> 13392 The name of the Postfix SMTP server's local SASL authentication 13393 realm. 13394 </p> 13395 13396 <p> 13397 By default, the local authentication realm name is the null string. 13398 </p> 13399 13400 <p> 13401 Examples: 13402 </p> 13403 13404 <pre> 13405 <a href="postconf.5.html#smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> = $<a href="postconf.5.html#mydomain">mydomain</a> 13406 <a href="postconf.5.html#smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> = $<a href="postconf.5.html#myhostname">myhostname</a> 13407 </pre> 13408 13409 13410 </DD> 13411 13412 <DT><b><a name="smtpd_sasl_path">smtpd_sasl_path</a> 13413 (default: smtpd)</b></DT><DD> 13414 13415 <p> Implementation-specific information that the Postfix SMTP server 13416 passes through to 13417 the SASL plug-in implementation that is selected with 13418 <b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a></b>. Typically this specifies the name of a 13419 configuration file or rendezvous point. </p> 13420 13421 <p> This feature is available in Postfix 2.3 and later. In earlier 13422 releases it was called <b><a href="postconf.5.html#smtpd_sasl_application_name">smtpd_sasl_application_name</a></b>. </p> 13423 13424 13425 </DD> 13426 13427 <DT><b><a name="smtpd_sasl_security_options">smtpd_sasl_security_options</a> 13428 (default: noanonymous)</b></DT><DD> 13429 13430 <p> Postfix SMTP server SASL security options; as of Postfix 2.3 13431 the list of available 13432 features depends on the SASL server implementation that is selected 13433 with <b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a></b>. </p> 13434 13435 <p> The following security features are defined for the <b>cyrus</b> 13436 server SASL implementation: </p> 13437 13438 <p> 13439 Restrict what authentication mechanisms the Postfix SMTP server 13440 will offer to the client. The list of available authentication 13441 mechanisms is system dependent. 13442 </p> 13443 13444 <p> 13445 Specify zero or more of the following: 13446 </p> 13447 13448 <dl> 13449 13450 <dt><b>noplaintext</b></dt> 13451 13452 <dd>Disallow methods that use plaintext passwords. </dd> 13453 13454 <dt><b>noactive</b></dt> 13455 13456 <dd>Disallow methods subject to active (non-dictionary) attack. </dd> 13457 13458 <dt><b>nodictionary</b></dt> 13459 13460 <dd>Disallow methods subject to passive (dictionary) attack. </dd> 13461 13462 <dt><b>noanonymous</b></dt> 13463 13464 <dd>Disallow methods that allow anonymous authentication. </dd> 13465 13466 <dt><b>forward_secrecy</b></dt> 13467 13468 <dd>Only allow methods that support forward secrecy (Dovecot only). 13469 </dd> 13470 13471 <dt><b>mutual_auth</b></dt> 13472 13473 <dd>Only allow methods that provide mutual authentication (not available 13474 with Cyrus SASL version 1). </dd> 13475 13476 </dl> 13477 13478 <p> 13479 By default, the Postfix SMTP server accepts plaintext passwords but 13480 not anonymous logins. 13481 </p> 13482 13483 <p> 13484 Warning: it appears that clients try authentication methods in the 13485 order as advertised by the server (e.g., PLAIN ANONYMOUS CRAM-MD5) 13486 which means that if you disable plaintext passwords, clients will 13487 log in anonymously, even when they should be able to use CRAM-MD5. 13488 So, if you disable plaintext logins, disable anonymous logins too. 13489 Postfix treats anonymous login as no authentication. 13490 </p> 13491 13492 <p> 13493 Example: 13494 </p> 13495 13496 <pre> 13497 <a href="postconf.5.html#smtpd_sasl_security_options">smtpd_sasl_security_options</a> = noanonymous, noplaintext 13498 </pre> 13499 13500 13501 </DD> 13502 13503 <DT><b><a name="smtpd_sasl_tls_security_options">smtpd_sasl_tls_security_options</a> 13504 (default: $<a href="postconf.5.html#smtpd_sasl_security_options">smtpd_sasl_security_options</a>)</b></DT><DD> 13505 13506 <p> The SASL authentication security options that the Postfix SMTP 13507 server uses for TLS encrypted SMTP sessions. </p> 13508 13509 <p> This feature is available in Postfix 2.2 and later. </p> 13510 13511 13512 </DD> 13513 13514 <DT><b><a name="smtpd_sasl_type">smtpd_sasl_type</a> 13515 (default: cyrus)</b></DT><DD> 13516 13517 <p> The SASL plug-in type that the Postfix SMTP server should use 13518 for authentication. The available types are listed with the 13519 "<b>postconf -a</b>" command. </p> 13520 13521 <p> This feature is available in Postfix 2.3 and later. </p> 13522 13523 13524 </DD> 13525 13526 <DT><b><a name="smtpd_sender_login_maps">smtpd_sender_login_maps</a> 13527 (default: empty)</b></DT><DD> 13528 13529 <p> 13530 Optional lookup table with the SASL login names that own sender 13531 (MAIL FROM) addresses. 13532 </p> 13533 13534 <p> 13535 Specify zero or more "<a href="DATABASE_README.html">type:table</a>" lookup tables. With lookups from 13536 indexed files such as DB or DBM, or from networked tables such as 13537 NIS, LDAP or SQL, the following search operations are done with a 13538 sender address of <i>user@domain</i>: </p> 13539 13540 <dl> 13541 13542 <dt> 1) <i>user@domain</i> </dt> 13543 13544 <dd>This table lookup is always done and has the highest precedence. </dd> 13545 13546 <dt> 2) <i>user</i> </dt> 13547 13548 <dd>This table lookup is done only when the <i>domain</i> part of the 13549 sender address matches $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> 13550 or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. </dd> 13551 13552 <dt> 3) <i>@domain</i> </dt> 13553 13554 <dd>This table lookup is done last and has the lowest precedence. </dd> 13555 13556 </dl> 13557 13558 <p> 13559 In all cases the result of table lookup must be either "not found" 13560 or a list of SASL login names separated by comma and/or whitespace. 13561 </p> 13562 13563 13564 </DD> 13565 13566 <DT><b><a name="smtpd_sender_restrictions">smtpd_sender_restrictions</a> 13567 (default: empty)</b></DT><DD> 13568 13569 <p> 13570 Optional restrictions that the Postfix SMTP server applies in the 13571 context of the MAIL FROM command. 13572 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 13573 restriction lists" for a discussion of evaluation context and time. 13574 </p> 13575 13576 <p> 13577 The default is to permit everything. 13578 </p> 13579 13580 <p> 13581 Specify a list of restrictions, separated by commas and/or whitespace. 13582 Continue long lines by starting the next line with whitespace. 13583 Restrictions are applied in the order as specified; the first 13584 restriction that matches wins. 13585 </p> 13586 13587 <p> 13588 The following restrictions are specific to the sender address 13589 received with the MAIL FROM command. 13590 </p> 13591 13592 <dl> 13593 13594 <dt><b><a name="check_sender_access">check_sender_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 13595 13596 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MAIL FROM 13597 address, domain, parent domains, or localpart@, and execute the 13598 corresponding action. </dd> 13599 13600 <dt><b><a name="check_sender_mx_access">check_sender_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 13601 13602 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for 13603 the MAIL FROM address, and execute the corresponding action. Note: 13604 a result of "OK" is not allowed for safety reasons. Instead, use 13605 DUNNO in order to exclude specific hosts from blacklists. This 13606 feature is available in Postfix 2.1 and later. </dd> 13607 13608 <dt><b><a name="check_sender_ns_access">check_sender_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 13609 13610 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers 13611 for the MAIL FROM address, and execute the corresponding action. 13612 Note: a result of "OK" is not allowed for safety reasons. Instead, 13613 use DUNNO in order to exclude specific hosts from blacklists. This 13614 feature is available in Postfix 2.1 and later. </dd> 13615 13616 <dt><b><a name="reject_authenticated_sender_login_mismatch">reject_authenticated_sender_login_mismatch</a></b></dt> 13617 13618 <dd>Enforces the <a href="postconf.5.html#reject_sender_login_mismatch">reject_sender_login_mismatch</a> restriction for 13619 authenticated clients only. This feature is available in 13620 Postfix version 2.1 and later. </dd> 13621 13622 <dt><b><a name="reject_non_fqdn_sender">reject_non_fqdn_sender</a></b></dt> 13623 13624 <dd>Reject the request when the MAIL FROM address is not in 13625 fully-qualified domain form, as required by the RFC. <br> The 13626 <a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> parameter specifies the response code for 13627 rejected requests (default: 504). </dd> 13628 13629 <dt><b><a name="reject_rhsbl_sender">reject_rhsbl_sender <i>rbl_domain=d.d.d.d</i></a></b></dt> 13630 13631 <dd>Reject the request when the MAIL FROM domain is listed with 13632 the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> (Postfix 13633 version 2.1 and later only). Each "<i>d</i>" is a number, or a 13634 pattern inside "[]" that contains one or more ";"-separated numbers 13635 or number..number ranges (Postfix version 2.8 and later). If no 13636 "<i>=d.d.d.d</i>" is specified, 13637 reject the request when the MAIL FROM domain is 13638 listed with any A record under <i>rbl_domain</i>. <br> The 13639 <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> parameter specifies the response code for 13640 rejected requests (default: 554); the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> parameter 13641 specifies the default server reply; and the <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> parameter 13642 specifies tables with server replies indexed by <i>rbl_domain</i>. 13643 This feature is available in Postfix 2.0 and later.</dd> 13644 13645 <dt><b><a name="reject_sender_login_mismatch">reject_sender_login_mismatch</a></b></dt> 13646 13647 <dd>Reject the request when $<a href="postconf.5.html#smtpd_sender_login_maps">smtpd_sender_login_maps</a> specifies an 13648 owner for the MAIL FROM address, but the client is not (SASL) logged 13649 in as that MAIL FROM address owner; or when the client is (SASL) 13650 logged in, but the client login name doesn't own the MAIL FROM 13651 address according to $<a href="postconf.5.html#smtpd_sender_login_maps">smtpd_sender_login_maps</a>.</dd> 13652 13653 <dt><b><a name="reject_unauthenticated_sender_login_mismatch">reject_unauthenticated_sender_login_mismatch</a></b></dt> 13654 13655 <dd>Enforces the <a href="postconf.5.html#reject_sender_login_mismatch">reject_sender_login_mismatch</a> restriction for 13656 unauthenticated clients only. This feature is available in 13657 Postfix version 2.1 and later. </dd> 13658 13659 <dt><b><a name="reject_unknown_sender_domain">reject_unknown_sender_domain</a></b></dt> 13660 13661 <dd>Reject the request when Postfix is not final destination for 13662 the sender address, and the MAIL FROM address has no DNS A or MX 13663 record, or when it has a malformed MX record such as a record with 13664 a zero-length MX hostname (Postfix version 2.3 and later). <br> The 13665 <a href="postconf.5.html#unknown_address_reject_code">unknown_address_reject_code</a> parameter specifies the numerical 13666 response code for rejected requests (default: 450). The response 13667 is always 450 in case of a temporary DNS error. <br> The 13668 <a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a> parameter specifies the action 13669 after a temporary DNS error (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). </dd> 13670 13671 <dt><b><a name="reject_unlisted_sender">reject_unlisted_sender</a></b></dt> 13672 13673 <dd>Reject the request when the MAIL FROM address is not listed in 13674 the list of valid recipients for its domain class. See the 13675 <a href="postconf.5.html#smtpd_reject_unlisted_sender">smtpd_reject_unlisted_sender</a> parameter description for details. 13676 This feature is available in Postfix 2.1 and later.</dd> 13677 13678 <dt><b><a name="reject_unverified_sender">reject_unverified_sender</a></b></dt> 13679 13680 <dd>Reject the request when mail to the MAIL FROM address is known to 13681 bounce, or when the sender address destination is not reachable. 13682 Address verification information is managed by the <a href="verify.8.html">verify(8)</a> server; 13683 see the <a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VERIFICATION_README</a> file for details. <br> The 13684 <a href="postconf.5.html#unverified_sender_reject_code">unverified_sender_reject_code</a> parameter specifies the numerical 13685 response code when an address is known to bounce (default: 450, 13686 change into 550 when you are confident that it is safe to do so). 13687 <br>The <a href="postconf.5.html#unverified_sender_defer_code">unverified_sender_defer_code</a> specifies the numerical response 13688 code when an address address probe failed due to a temporary problem 13689 (default: 450). <br> The <a href="postconf.5.html#unverified_sender_tempfail_action">unverified_sender_tempfail_action</a> parameter 13690 specifies the action after address probe failure due to a temporary 13691 problem (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). <br> This feature is available 13692 in Postfix 2.1 and later. </dd> 13693 13694 </dl> 13695 13696 <p> 13697 Other restrictions that are valid in this context: 13698 </p> 13699 13700 <ul> 13701 13702 <li> <a href="#generic">Generic</a> restrictions that can be used 13703 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 13704 13705 <li> SMTP command specific restrictions described under 13706 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> and <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>. 13707 13708 <li> SMTP command specific restrictions described under 13709 <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>. When recipient restrictions are listed 13710 under <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>, they have effect only with 13711 "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes", so that $<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> is 13712 evaluated at the time of the RCPT TO command. 13713 13714 </ul> 13715 13716 <p> 13717 Examples: 13718 </p> 13719 13720 <pre> 13721 <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> = <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a> 13722 <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> = <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a>, 13723 <a href="postconf.5.html#check_sender_access">check_sender_access</a> hash:/etc/postfix/access 13724 </pre> 13725 13726 13727 </DD> 13728 13729 <DT><b><a name="smtpd_service_name">smtpd_service_name</a> 13730 (default: smtpd)</b></DT><DD> 13731 13732 <p> The internal service that <a href="postscreen.8.html">postscreen(8)</a> forwards allowed 13733 connections to. In a future version there may be different 13734 classes of SMTP service. </p> 13735 13736 <p> This feature is available in Postfix 2.8. </p> 13737 13738 13739 </DD> 13740 13741 <DT><b><a name="smtpd_soft_error_limit">smtpd_soft_error_limit</a> 13742 (default: 10)</b></DT><DD> 13743 13744 <p> 13745 The number of errors a remote SMTP client is allowed to make without 13746 delivering mail before the Postfix SMTP server slows down all its 13747 responses. 13748 </p> 13749 13750 <ul> 13751 13752 <li><p>With Postfix version 2.1 and later, the Postfix SMTP server 13753 delays all responses by $<a href="postconf.5.html#smtpd_error_sleep_time">smtpd_error_sleep_time</a> seconds. </p> 13754 13755 <li><p>With Postfix versions 2.0 and earlier, the Postfix SMTP 13756 server delays all responses by (number of errors) seconds. </p> 13757 13758 </ul> 13759 13760 13761 </DD> 13762 13763 <DT><b><a name="smtpd_starttls_timeout">smtpd_starttls_timeout</a> 13764 (default: see "postconf -d" output)</b></DT><DD> 13765 13766 <p> The time limit for Postfix SMTP server write and read operations 13767 during TLS startup and shutdown handshake procedures. The current 13768 default value is stress-dependent. Before Postfix version 2.8, it 13769 was fixed at 300s. </p> 13770 13771 <p> This feature is available in Postfix 2.2 and later. </p> 13772 13773 13774 </DD> 13775 13776 <DT><b><a name="smtpd_timeout">smtpd_timeout</a> 13777 (default: normal: 300s, overload: 10s)</b></DT><DD> 13778 13779 <p> 13780 The time limit for sending a Postfix SMTP server response and for 13781 receiving a remote SMTP client request. Normally the default limit 13782 is 300s, but it changes under overload to just 10s. With Postfix 13783 2.5 and earlier, the SMTP server always uses a time limit of 300s 13784 by default. 13785 </p> 13786 13787 <p> 13788 Note: if you set SMTP time limits to very large values you may have 13789 to update the global <a href="postconf.5.html#ipc_timeout">ipc_timeout</a> parameter. 13790 </p> 13791 13792 <p> 13793 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 13794 The default time unit is s (seconds). 13795 </p> 13796 13797 13798 </DD> 13799 13800 <DT><b><a name="smtpd_tls_CAfile">smtpd_tls_CAfile</a> 13801 (default: empty)</b></DT><DD> 13802 13803 <p> A file containing (PEM format) CA certificates of root CAs trusted 13804 to sign either remote SMTP client certificates or intermediate CA 13805 certificates. These are loaded into memory before the <a href="smtpd.8.html">smtpd(8)</a> server 13806 enters the chroot jail. If the number of trusted roots is large, consider 13807 using <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> instead, but note that the latter directory must 13808 be present in the chroot jail if the <a href="smtpd.8.html">smtpd(8)</a> server is chrooted. This 13809 file may also be used to augment the server certificate trust chain, 13810 but it is best to include all the required certificates directly in the 13811 server certificate file. </p> 13812 13813 <p> Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" to prevent Postfix from 13814 appending the system-supplied default CAs and trusting third-party 13815 certificates. </p> 13816 13817 <p> By default (see <a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>), client certificates are not 13818 requested, and <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> should remain empty. If you do make use 13819 of client certificates, the distinguished names (DNs) of the certificate 13820 authorities listed in <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> are sent to the remote SMTP client 13821 in the client certificate request message. MUAs with multiple client 13822 certificates may use the list of preferred certificate authorities 13823 to select the correct client certificate. You may want to put your 13824 "preferred" CA or CAs in this file, and install other trusted CAs in 13825 $<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>. </p> 13826 13827 <p> Example: </p> 13828 13829 <pre> 13830 <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> = /etc/postfix/CAcert.pem 13831 </pre> 13832 13833 <p> This feature is available in Postfix 2.2 and later. </p> 13834 13835 13836 </DD> 13837 13838 <DT><b><a name="smtpd_tls_CApath">smtpd_tls_CApath</a> 13839 (default: empty)</b></DT><DD> 13840 13841 <p> A directory containing (PEM format) CA certificates of root CAs 13842 trusted to sign either remote SMTP client certificates or intermediate CA 13843 certificates. Do not forget to create the necessary "hash" links with, 13844 for example, "$OPENSSL_HOME/bin/c_rehash /etc/postfix/certs". To use 13845 <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> in chroot mode, this directory (or a copy) must be 13846 inside the chroot jail. </p> 13847 13848 <p> Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" to prevent Postfix from 13849 appending the system-supplied default CAs and trusting third-party 13850 certificates. </p> 13851 13852 <p> By default (see <a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>), client certificates are 13853 not requested, and <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> should remain empty. In contrast 13854 to <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>, DNs of certificate authorities installed 13855 in $<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> are not included in the client certificate 13856 request message. MUAs with multiple client certificates may use the 13857 list of preferred certificate authorities to select the correct 13858 client certificate. You may want to put your "preferred" CA or 13859 CAs in $<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>, and install the remaining trusted CAs in 13860 $<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>. </p> 13861 13862 <p> Example: </p> 13863 13864 <pre> 13865 <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> = /etc/postfix/certs 13866 </pre> 13867 13868 <p> This feature is available in Postfix 2.2 and later. </p> 13869 13870 13871 </DD> 13872 13873 <DT><b><a name="smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a> 13874 (default: yes)</b></DT><DD> 13875 13876 <p> Force the Postfix SMTP server to issue a TLS session id, even 13877 when TLS session caching is turned off (<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> 13878 is empty). This behavior is compatible with Postfix < 2.3. </p> 13879 13880 <p> With Postfix 2.3 and later the Postfix SMTP server can disable 13881 session id generation when TLS session caching is turned off. This 13882 keeps clients from caching sessions that almost certainly cannot 13883 be re-used. </p> 13884 13885 <p> By default, the Postfix SMTP server always generates TLS session 13886 ids. This works around a known defect in mail client applications 13887 such as MS Outlook, and may also prevent interoperability issues 13888 with other MTAs. </p> 13889 13890 <p> Example: </p> 13891 13892 <pre> 13893 <a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a> = no 13894 </pre> 13895 13896 <p> This feature is available in Postfix 2.3 and later. </p> 13897 13898 13899 </DD> 13900 13901 <DT><b><a name="smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a> 13902 (default: no)</b></DT><DD> 13903 13904 <p> Ask a remote SMTP client for a client certificate. This 13905 information is needed for certificate based mail relaying with, 13906 for example, the <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> feature. </p> 13907 13908 <p> Some clients such as Netscape will either complain if no 13909 certificate is available (for the list of CAs in $<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>) 13910 or will offer multiple client certificates to choose from. This 13911 may be annoying, so this option is "off" by default. </p> 13912 13913 <p> This feature is available in Postfix 2.2 and later. </p> 13914 13915 13916 </DD> 13917 13918 <DT><b><a name="smtpd_tls_auth_only">smtpd_tls_auth_only</a> 13919 (default: no)</b></DT><DD> 13920 13921 <p> When TLS encryption is optional in the Postfix SMTP server, do 13922 not announce or accept SASL authentication over unencrypted 13923 connections. </p> 13924 13925 <p> This feature is available in Postfix 2.2 and later. </p> 13926 13927 13928 </DD> 13929 13930 <DT><b><a name="smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a> 13931 (default: 9)</b></DT><DD> 13932 13933 <p> The verification depth for remote SMTP client certificates. A 13934 depth of 1 is sufficient if the issuing CA is listed in a local CA 13935 file. </p> 13936 13937 <p> The default verification depth is 9 (the OpenSSL default) for 13938 compatibility with earlier Postfix behavior. Prior to Postfix 2.5, 13939 the default value was 5, but the limit was not actually enforced. If 13940 you have set this to a lower non-default value, certificates with longer 13941 trust chains may now fail to verify. Certificate chains with 1 or 2 13942 CAs are common, deeper chains are more rare and any number between 5 13943 and 9 should suffice in practice. You can choose a lower number if, 13944 for example, you trust certificates directly signed by an issuing CA 13945 but not any CAs it delegates to. </p> 13946 13947 <p> This feature is available in Postfix 2.2 and later. </p> 13948 13949 13950 </DD> 13951 13952 <DT><b><a name="smtpd_tls_cert_file">smtpd_tls_cert_file</a> 13953 (default: empty)</b></DT><DD> 13954 13955 <p> File with the Postfix SMTP server RSA certificate in PEM format. 13956 This file may also contain the Postfix SMTP server private RSA key. </p> 13957 13958 <p> Public Internet MX hosts without certificates signed by a "reputable" 13959 CA must generate, and be prepared to present to most clients, a 13960 self-signed or private-CA signed certificate. The client will not be 13961 able to authenticate the server, but unless it is running Postfix 2.3 or 13962 similar software, it will still insist on a server certificate. </p> 13963 13964 <p> For servers that are <b>not</b> public Internet MX hosts, Postfix 13965 2.3 supports configurations with no certificates. This entails the 13966 use of just the anonymous TLS ciphers, which are not supported by 13967 typical SMTP clients. Since such clients will not, as a rule, fall 13968 back to plain text after a TLS handshake failure, the server will 13969 be unable to receive email from TLS enabled clients. To avoid 13970 accidental configurations with no certificates, Postfix 2.3 enables 13971 certificate-less operation only when the administrator explicitly 13972 sets "<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> = none". This ensures that new Postfix 13973 configurations will not accidentally run with no certificates. </p> 13974 13975 <p> Both RSA and DSA certificates are supported. When both types 13976 are present, the cipher used determines which certificate will be 13977 presented to the client. For Netscape and OpenSSL clients without 13978 special cipher choices the RSA certificate is preferred. </p> 13979 13980 <p> To enable a remote SMTP client to verify the Postfix SMTP server 13981 certificate, the issuing CA certificates must be made available to the 13982 client. You should include the required certificates in the server 13983 certificate file, the server certificate first, then the issuing 13984 CA(s) (bottom-up order). </p> 13985 13986 <p> Example: the certificate for "server.example.com" was issued by 13987 "intermediate CA" which itself has a certificate of "root CA". 13988 Create the server.pem file with "cat server_cert.pem intermediate_CA.pem 13989 root_CA.pem > server.pem". </p> 13990 13991 <p> If you also want to verify client certificates issued by these 13992 CAs, you can add the CA certificates to the <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>, in which 13993 case it is not necessary to have them in the <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> or 13994 <a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>. </p> 13995 13996 <p> A certificate supplied here must be usable as an SSL server certificate 13997 and hence pass the "openssl verify -purpose sslserver ..." test. </p> 13998 13999 <p> Example: </p> 14000 14001 <pre> 14002 <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> = /etc/postfix/server.pem 14003 </pre> 14004 14005 <p> This feature is available in Postfix 2.2 and later. </p> 14006 14007 14008 </DD> 14009 14010 <DT><b><a name="smtpd_tls_cipherlist">smtpd_tls_cipherlist</a> 14011 (default: empty)</b></DT><DD> 14012 14013 <p> Obsolete Postfix < 2.3 control for the Postfix SMTP server TLS 14014 cipher list. It is easy to create inter-operability problems by choosing 14015 a non-default cipher list. Do not use a non-default TLS cipherlist for 14016 MX hosts on the public Internet. Clients that begin the TLS handshake, 14017 but are unable to agree on a common cipher, may not be able to send any 14018 email to the SMTP server. Using a restricted cipher list may be more 14019 appropriate for a dedicated MSA or an internal mailhub, where one can 14020 exert some control over the TLS software and settings of the connecting 14021 clients. </p> 14022 14023 <p> <b>Note:</b> do not use "" quotes around the parameter value. </p> 14024 14025 <p>This feature is available with Postfix version 2.2. It is not used with 14026 Postfix 2.3 and later; use <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> instead. </p> 14027 14028 14029 </DD> 14030 14031 <DT><b><a name="smtpd_tls_ciphers">smtpd_tls_ciphers</a> 14032 (default: export)</b></DT><DD> 14033 14034 <p> The minimum TLS cipher grade that the Postfix SMTP server 14035 will use with opportunistic TLS encryption. Cipher types listed in 14036 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> are excluded from the base definition of 14037 the selected cipher grade. The default value "export" ensures maximum 14038 inter-operability. Because encryption is optional, stronger controls 14039 are not appropriate, and this setting SHOULD NOT be changed unless the 14040 change is essential. </p> 14041 14042 <p> When TLS is mandatory the cipher grade is chosen via the 14043 <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> configuration parameter, see there for syntax 14044 details. </p> 14045 14046 <p> Example: </p> 14047 <pre> 14048 <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> = export 14049 </pre> 14050 14051 <p> This feature is available in Postfix 2.6 and later. With earlier Postfix 14052 releases only the <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> parameter is implemented, 14053 and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p> 14054 14055 14056 </DD> 14057 14058 <DT><b><a name="smtpd_tls_dcert_file">smtpd_tls_dcert_file</a> 14059 (default: empty)</b></DT><DD> 14060 14061 <p> File with the Postfix SMTP server DSA certificate in PEM format. 14062 This file may also contain the Postfix SMTP server private DSA key. </p> 14063 14064 <p> See the discussion under <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> for more details. 14065 </p> 14066 14067 <p> Example: </p> 14068 14069 <pre> 14070 <a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a> = /etc/postfix/server-dsa.pem 14071 </pre> 14072 14073 <p> This feature is available in Postfix 2.2 and later. </p> 14074 14075 14076 </DD> 14077 14078 <DT><b><a name="smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a> 14079 (default: empty)</b></DT><DD> 14080 14081 <p> File with DH parameters that the Postfix SMTP server should 14082 use with EDH ciphers. </p> 14083 14084 <p> Instead of using the exact same parameter sets as distributed 14085 with other TLS packages, it is more secure to generate your own 14086 set of parameters with something like the following command: </p> 14087 14088 <blockquote> 14089 <pre> 14090 openssl gendh -out /etc/postfix/dh_1024.pem -2 1024 14091 </pre> 14092 </blockquote> 14093 14094 <p> Your actual source for entropy may differ. Some systems have 14095 /dev/random; on other system you may consider using the "Entropy 14096 Gathering Daemon EGD", available at <a href="http://egd.sourceforge.net/">http://egd.sourceforge.net/</a> 14097 </p> 14098 14099 <p> Example: </p> 14100 14101 <pre> 14102 <a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a> = /etc/postfix/dh_1024.pem 14103 </pre> 14104 14105 <p>This feature is available with Postfix version 2.2.</p> 14106 14107 14108 </DD> 14109 14110 <DT><b><a name="smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a> 14111 (default: empty)</b></DT><DD> 14112 14113 <p> File with DH parameters that the Postfix SMTP server should 14114 use with EDH ciphers. </p> 14115 14116 <p> See also the discussion under the <a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a> 14117 configuration parameter. </p> 14118 14119 <p> Example: </p> 14120 14121 <pre> 14122 <a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a> = /etc/postfix/dh_512.pem 14123 </pre> 14124 14125 <p>This feature is available with Postfix version 2.2.</p> 14126 14127 14128 </DD> 14129 14130 <DT><b><a name="smtpd_tls_dkey_file">smtpd_tls_dkey_file</a> 14131 (default: $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>)</b></DT><DD> 14132 14133 <p> File with the Postfix SMTP server DSA private key in PEM format. 14134 This file may be combined with the Postfix SMTP server DSA certificate 14135 file specified with $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>. </p> 14136 14137 <p> The private key must be accessible without a pass-phrase, i.e. it 14138 must not be encrypted. File permissions should grant read-only 14139 access to the system superuser account ("root"), and no access 14140 to anyone else. </p> 14141 14142 <p> This feature is available in Postfix 2.2 and later. </p> 14143 14144 14145 </DD> 14146 14147 <DT><b><a name="smtpd_tls_eccert_file">smtpd_tls_eccert_file</a> 14148 (default: empty)</b></DT><DD> 14149 14150 <p> File with the Postfix SMTP server ECDSA certificate in PEM format. 14151 This file may also contain the Postfix SMTP server private ECDSA key. </p> 14152 14153 <p> See the discussion under <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> for more details. </p> 14154 14155 <p> Example: </p> 14156 14157 <pre> 14158 <a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a> = /etc/postfix/ecdsa-scert.pem 14159 </pre> 14160 14161 <p> This feature is available in Postfix 2.6 and later, when Postfix is 14162 compiled and linked with OpenSSL 1.0.0 or later. </p> 14163 14164 14165 </DD> 14166 14167 <DT><b><a name="smtpd_tls_eckey_file">smtpd_tls_eckey_file</a> 14168 (default: $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>)</b></DT><DD> 14169 14170 <p> File with the Postfix SMTP server ECDSA private key in PEM format. 14171 This file may be combined with the Postfix SMTP server ECDSA certificate 14172 file specified with $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>. </p> 14173 14174 <p> The private key must be accessible without a pass-phrase, i.e. it 14175 must not be encrypted. File permissions should grant read-only 14176 access to the system superuser account ("root"), and no access 14177 to anyone else. </p> 14178 14179 <p> This feature is available in Postfix 2.6 and later, when Postfix is 14180 compiled and linked with OpenSSL 1.0.0 or later. </p> 14181 14182 14183 </DD> 14184 14185 <DT><b><a name="smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> 14186 (default: see "postconf -d" output)</b></DT><DD> 14187 14188 <p> The Postfix SMTP server security grade for ephemeral elliptic-curve 14189 Diffie-Hellman (EECDH) key exchange. </p> 14190 14191 <p> The available choices are: </p> 14192 14193 <dl> 14194 14195 <dt><b>none</b></dt> <dd> Don't use EECDH. Ciphers based on EECDH key 14196 exchange will be disabled. This is the default in Postfix versions 14197 2.6 and 2.7. </dd> 14198 14199 <dt><b>strong</b></dt> <dd> Use EECDH with approximately 128 14200 bits of security at a reasonable computational cost. This is the 14201 current best-practice trade-off between security and computational 14202 efficiency. This is the default in Postfix version 2.8 and later. 14203 </dd> 14204 14205 <dt><b>ultra</b></dt> <dd> Use EECDH with approximately 192 bits of 14206 security at computational cost that is approximately twice as high 14207 as 128 bit strength ECC. Barring significant progress in attacks on 14208 elliptic curve crypto-systems, the "strong" curve is sufficient for most 14209 users. </dd> 14210 14211 </dl> 14212 14213 <p> This feature is available in Postfix 2.6 and later, when it is 14214 compiled and linked with OpenSSL 1.0.0 or later. </p> 14215 14216 14217 </DD> 14218 14219 <DT><b><a name="smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> 14220 (default: empty)</b></DT><DD> 14221 14222 <p> List of ciphers or cipher types to exclude from the SMTP server 14223 cipher list at all TLS security levels. Excluding valid ciphers 14224 can create interoperability problems. DO NOT exclude ciphers unless it 14225 is essential to do so. This is not an OpenSSL cipherlist; it is a simple 14226 list separated by whitespace and/or commas. The elements are a single 14227 cipher, or one or more "+" separated cipher properties, in which case 14228 only ciphers matching <b>all</b> the properties are excluded. </p> 14229 14230 <p> Examples (some of these will cause problems): </p> 14231 14232 <blockquote> 14233 <pre> 14234 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = aNULL 14235 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = MD5, DES 14236 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = DES+MD5 14237 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = AES256-SHA, DES-CBC3-MD5 14238 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = kEDH+aRSA 14239 </pre> 14240 </blockquote> 14241 14242 <p> The first setting disables anonymous ciphers. The next setting 14243 disables ciphers that use the MD5 digest algorithm or the (single) DES 14244 encryption algorithm. The next setting disables ciphers that use MD5 and 14245 DES together. The next setting disables the two ciphers "AES256-SHA" 14246 and "DES-CBC3-MD5". The last setting disables ciphers that use "EDH" 14247 key exchange with RSA authentication. </p> 14248 14249 <p> This feature is available in Postfix 2.3 and later. </p> 14250 14251 14252 </DD> 14253 14254 <DT><b><a name="smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> 14255 (default: md5)</b></DT><DD> 14256 14257 <p> The message digest algorithm used to construct client-certificate 14258 fingerprints for <b><a href="postconf.5.html#check_ccert_access">check_ccert_access</a></b> and 14259 <b><a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a></b>. The default algorithm is <b>md5</b>, 14260 for backwards compatibility with Postfix releases prior to 2.5. 14261 </p> 14262 14263 <p> The best practice algorithm is now <b>sha1</b>. Recent advances in hash 14264 function cryptanalysis have led to md5 being deprecated in favor of sha1. 14265 However, as long as there are no known "second pre-image" attacks 14266 against md5, its use in this context can still be considered safe. 14267 </p> 14268 14269 <p> While additional digest algorithms are often available with OpenSSL's 14270 libcrypto, only those used by libssl in SSL cipher suites are available to 14271 Postfix. For now this means just md5 or sha1. </p> 14272 14273 <p> To find the fingerprint of a specific certificate file, with a 14274 specific digest algorithm, run: </p> 14275 14276 <blockquote> 14277 <pre> 14278 $ openssl x509 -noout -fingerprint -<i>digest</i> -in <i>certfile</i>.pem 14279 </pre> 14280 </blockquote> 14281 14282 <p> The text to the right of "=" sign is the desired fingerprint. 14283 For example: </p> 14284 14285 <blockquote> 14286 <pre> 14287 $ openssl x509 -noout -fingerprint -sha1 -in cert.pem 14288 SHA1 Fingerprint=D4:6A:AB:19:24:79:F8:32:BB:A6:CB:66:82:C0:8E:9B:EE:29:A8:1A 14289 </pre> 14290 </blockquote> 14291 14292 <p> Example: client-certificate access table, with sha1 fingerprints: </p> 14293 14294 <blockquote> 14295 <pre> 14296 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 14297 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> = sha1 14298 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> = 14299 <a href="postconf.5.html#check_ccert_access">check_ccert_access</a> hash:/etc/postfix/access, 14300 reject 14301 </pre> 14302 <pre> 14303 /etc/postfix/access: 14304 # Action folded to next line... 14305 AF:88:7C:AD:51:95:6F:36:96:F6:01:FB:2E:48:CD:AB:49:25:A2:3B 14306 OK 14307 85:16:78:FD:73:6E:CE:70:E0:31:5F:0D:3C:C8:6D:C4:2C:24:59:E1 14308 <a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a> 14309 </pre> 14310 </blockquote> 14311 14312 <p> This feature is available in Postfix 2.5 and later. </p> 14313 14314 14315 </DD> 14316 14317 <DT><b><a name="smtpd_tls_key_file">smtpd_tls_key_file</a> 14318 (default: $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>)</b></DT><DD> 14319 14320 <p> File with the Postfix SMTP server RSA private key in PEM format. 14321 This file may be combined with the Postfix SMTP server RSA certificate 14322 file specified with $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>. </p> 14323 14324 <p> The private key must be accessible without a pass-phrase, i.e. it 14325 must not be encrypted. File permissions should grant read-only 14326 access to the system superuser account ("root"), and no access 14327 to anyone else. </p> 14328 14329 14330 </DD> 14331 14332 <DT><b><a name="smtpd_tls_loglevel">smtpd_tls_loglevel</a> 14333 (default: 0)</b></DT><DD> 14334 14335 <p> Enable additional Postfix SMTP server logging of TLS activity. 14336 Each logging level also includes the information that is logged at 14337 a lower logging level. </p> 14338 14339 <dl compact> 14340 14341 <dt> </dt> <dd> 0 Disable logging of TLS activity. </dd> 14342 14343 <dt> </dt> <dd> 1 Log TLS handshake and certificate information. </dd> 14344 14345 <dt> </dt> <dd> 2 Log levels during TLS negotiation. </dd> 14346 14347 <dt> </dt> <dd> 3 Log hexadecimal and ASCII dump of TLS negotiation 14348 process. </dd> 14349 14350 <dt> </dt> <dd> 4 Also log hexadecimal and ASCII dump of complete 14351 transmission after STARTTLS. </dd> 14352 14353 </dl> 14354 14355 <p> Use "<a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a> = 3" only in case of problems. Use of 14356 loglevel 4 is strongly discouraged. </p> 14357 14358 <p> This feature is available in Postfix 2.2 and later. </p> 14359 14360 14361 </DD> 14362 14363 <DT><b><a name="smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> 14364 (default: medium)</b></DT><DD> 14365 14366 <p> The minimum TLS cipher grade that the Postfix SMTP server will 14367 use with mandatory TLS encryption. The default grade ("medium") is 14368 sufficiently strong that any benefit from globally restricting TLS 14369 sessions to a more stringent grade is likely negligible, especially 14370 given the fact that many implementations still do not offer any stronger 14371 ("high" grade) ciphers, while those that do, will always use "high" 14372 grade ciphers. So insisting on "high" grade ciphers is generally 14373 counter-productive. Allowing "export" or "low" ciphers is typically 14374 not a good idea, as systems limited to just these are limited to 14375 obsolete browsers. No known SMTP clients fail to support at least 14376 one "medium" or "high" grade cipher. </p> 14377 14378 <p> The following cipher grades are supported: </p> 14379 14380 <dl> 14381 <dt><b>export</b></dt> 14382 <dd> Enable "EXPORT" grade or stronger OpenSSL ciphers. 14383 This is the most appropriate setting for public MX hosts, and is always 14384 used with opportunistic TLS encryption. The underlying cipherlist 14385 is specified via the <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> configuration parameter, 14386 which you are strongly encouraged to not change. </dd> 14387 14388 <dt><b>low</b></dt> 14389 <dd> Enable "LOW" grade or stronger OpenSSL ciphers. The 14390 underlying cipherlist is specified via the <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> 14391 configuration parameter, which you are strongly encouraged to 14392 not change. </dd> 14393 14394 <dt><b>medium</b></dt> 14395 <dd> Enable "MEDIUM" grade or stronger OpenSSL ciphers. These use 128-bit 14396 or longer symmetric bulk-encryption keys. This is the default minimum 14397 strength for mandatory TLS encryption. The underlying cipherlist is 14398 specified via the <a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> configuration parameter, which 14399 you are strongly encouraged to not change. </dd> 14400 14401 <dt><b>high</b></dt> 14402 <dd> Enable only "HIGH" grade OpenSSL ciphers. The 14403 underlying cipherlist is specified via the <a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a> 14404 configuration parameter, which you are strongly encouraged to 14405 not change. </dd> 14406 14407 <dt><b>null</b></dt> 14408 <dd> Enable only the "NULL" OpenSSL ciphers, these provide authentication 14409 without encryption. This setting is only appropriate in the rare 14410 case that all clients are prepared to use NULL ciphers (not normally 14411 enabled in TLS clients). The underlying cipherlist is specified via the 14412 <a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a> configuration parameter, which you are strongly 14413 encouraged to not change. </dd> 14414 14415 </dl> 14416 14417 <p> Cipher types listed in 14418 <a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> or <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> are 14419 excluded from the base definition of the selected cipher grade. See 14420 <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> for cipher controls that apply to opportunistic 14421 TLS. </p> 14422 14423 <p> The underlying cipherlists for grades other than "null" include 14424 anonymous ciphers, but these are automatically filtered out if the 14425 server is configured to ask for client certificates. You are very 14426 unlikely to need to take any steps to exclude anonymous ciphers, they 14427 are excluded automatically as required. If you must exclude anonymous 14428 ciphers even when Postfix does not need or use peer certificates, set 14429 "<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = aNULL". To exclude anonymous ciphers only 14430 when TLS is enforced, set "<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> = aNULL". </p> 14431 14432 <p> This feature is available in Postfix 2.3 and later. </p> 14433 14434 14435 </DD> 14436 14437 <DT><b><a name="smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> 14438 (default: empty)</b></DT><DD> 14439 14440 <p> Additional list of ciphers or cipher types to exclude from the 14441 SMTP server cipher list at mandatory TLS security levels. This list 14442 works in addition to the exclusions listed with <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> 14443 (see there for syntax details). </p> 14444 14445 <p> This feature is available in Postfix 2.3 and later. </p> 14446 14447 14448 </DD> 14449 14450 <DT><b><a name="smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> 14451 (default: !SSLv2)</b></DT><DD> 14452 14453 <p> The SSL/TLS protocols accepted by the Postfix SMTP server with 14454 mandatory TLS encryption. If the list is empty, the server supports all 14455 available SSL/TLS protocol versions. A non-empty value is a list 14456 of protocol 14457 names separated by whitespace, commas or colons. The supported protocol 14458 names are "SSLv2", "SSLv3" and "TLSv1", and are not case sensitive. </p> 14459 14460 <p> Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1" 14461 and "TLSv1.2". If an older Postfix version is linked against OpenSSL 14462 1.0.1 or later, these, or any other new protocol versions, are 14463 unconditionally enabled. </p> 14464 14465 <p> With Postfix ≥ 2.5 the parameter syntax is expanded to support 14466 protocol exclusions. One can now explicitly exclude SSLv2 by setting 14467 "<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = !SSLv2". To exclude both SSLv2 and 14468 SSLv3 set "<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = !SSLv2, !SSLv3". Listing 14469 the protocols to include, rather than protocols to exclude, is 14470 supported, but not recommended. The exclusion form more closely 14471 matches the behaviour when the OpenSSL library is newer than Postfix. 14472 </p> 14473 14474 <p> Since SSL version 2 has known protocol weaknesses and is now 14475 deprecated, the default setting excludes "SSLv2". This means that 14476 by default, SSL version 2 will not be used at the "encrypt" security 14477 level. </p> 14478 14479 <p> Example: </p> 14480 14481 <pre> 14482 <a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = TLSv1 14483 # Alternative form with Postfix ≥ 2.5: 14484 <a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = !SSLv2, !SSLv3 14485 </pre> 14486 14487 <p> This feature is available in Postfix 2.3 and later. </p> 14488 14489 14490 </DD> 14491 14492 <DT><b><a name="smtpd_tls_protocols">smtpd_tls_protocols</a> 14493 (default: empty)</b></DT><DD> 14494 14495 <p> List of TLS protocols that the Postfix SMTP server will exclude 14496 or include with opportunistic TLS encryption. This parameter SHOULD be 14497 left at its default empty value, allowing all protocols to be used with 14498 opportunistic TLS. </p> 14499 14500 <p> In <a href="postconf.5.html">main.cf</a> the values are separated by whitespace, commas or 14501 colons. An empty value means allow all protocols. The valid protocol 14502 names, (see <b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" and 14503 "TLSv1". In <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> table entries, "protocols" attribute 14504 values are separated by a colon. </p> 14505 14506 <p> Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1" 14507 and "TLSv1.2". If an older Postfix version is linked against OpenSSL 14508 1.0.1 or later, these, or any other new protocol versions, are 14509 unconditionally enabled. </p> 14510 14511 <p> To include a protocol list its name, to exclude it, prefix the name 14512 with a "!" character. To exclude SSLv2 even for opportunistic TLS set 14513 "<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2". To exclude both "SSLv2" and "SSLv3" set 14514 "<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2, !SSLv3". Explicitly listing the protocols to 14515 include, rather than protocols to exclude, is supported, but not 14516 recommended. The exclusion form more closely matches the behaviour 14517 when the OpenSSL library is newer than Postfix. </p> 14518 14519 <p> Example: </p> 14520 <pre> 14521 <a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2 14522 </pre> 14523 14524 <p> This feature is available in Postfix 2.6 and later. </p> 14525 14526 14527 </DD> 14528 14529 <DT><b><a name="smtpd_tls_received_header">smtpd_tls_received_header</a> 14530 (default: no)</b></DT><DD> 14531 14532 <p> Request that the Postfix SMTP server produces Received: message 14533 headers that include information about the protocol and cipher used, 14534 as well as the client CommonName and client certificate issuer 14535 CommonName. This is disabled by default, as the information may 14536 be modified in transit through other mail servers. Only information 14537 that was recorded by the final destination can be trusted. </p> 14538 14539 <p> This feature is available in Postfix 2.2 and later. </p> 14540 14541 14542 </DD> 14543 14544 <DT><b><a name="smtpd_tls_req_ccert">smtpd_tls_req_ccert</a> 14545 (default: no)</b></DT><DD> 14546 14547 <p> With mandatory TLS encryption, require a trusted remote SMTP client 14548 certificate in order to allow TLS connections to proceed. This 14549 option implies "<a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a> = yes". </p> 14550 14551 <p> When TLS encryption is optional, this setting is ignored with 14552 a warning written to the mail log. </p> 14553 14554 <p> This feature is available in Postfix 2.2 and later. </p> 14555 14556 14557 </DD> 14558 14559 <DT><b><a name="smtpd_tls_security_level">smtpd_tls_security_level</a> 14560 (default: empty)</b></DT><DD> 14561 14562 <p> The SMTP TLS security level for the Postfix SMTP server; when 14563 a non-empty value is specified, this overrides the obsolete parameters 14564 <a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> and <a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>. This parameter is ignored with 14565 "<a href="postconf.5.html#smtpd_tls_wrappermode">smtpd_tls_wrappermode</a> = yes". </p> 14566 14567 <p> Specify one of the following security levels: </p> 14568 14569 <dl> 14570 14571 <dt><b>none</b></dt> <dd> TLS will not be used. </dd> 14572 14573 <dt><b>may</b></dt> <dd> Opportunistic TLS: announce STARTTLS support 14574 to SMTP clients, but do not require that clients use TLS encryption. 14575 </dd> 14576 14577 <dt><b>encrypt</b></dt> <dd>Mandatory TLS encryption: announce 14578 STARTTLS support to SMTP clients, and require that clients use TLS 14579 encryption. According to <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> this MUST NOT be applied in case 14580 of a publicly-referenced SMTP server. Instead, this option should 14581 be used only on dedicated servers. </dd> 14582 14583 </dl> 14584 14585 <p> Note 1: the "fingerprint", "verify" and "secure" levels are not 14586 supported here. 14587 The Postfix SMTP server logs a warning and uses "encrypt" instead. 14588 To verify SMTP client certificates, see <a href="TLS_README.html">TLS_README</a> for a discussion 14589 of the <a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>, <a href="postconf.5.html#smtpd_tls_req_ccert">smtpd_tls_req_ccert</a>, and <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> 14590 features. </p> 14591 14592 <p> Note 2: The parameter setting "<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> = 14593 encrypt" implies "<a href="postconf.5.html#smtpd_tls_auth_only">smtpd_tls_auth_only</a> = yes".</p> 14594 14595 <p> Note 3: when invoked via "sendmail -bs", Postfix will never 14596 offer STARTTLS due to insufficient privileges to access the server 14597 private key. This is intended behavior.</p> 14598 14599 <p> This feature is available in Postfix 2.3 and later. </p> 14600 14601 14602 </DD> 14603 14604 <DT><b><a name="smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> 14605 (default: empty)</b></DT><DD> 14606 14607 <p> Name of the file containing the optional Postfix SMTP server 14608 TLS session cache. Specify a database type that supports enumeration, 14609 such as <b>btree</b> or <b>sdbm</b>; there is no need to support 14610 concurrent access. The file is created if it does not exist. The <a href="smtpd.8.html">smtpd(8)</a> 14611 daemon does not use this parameter directly, rather the cache is 14612 implemented indirectly in the <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon. This means that 14613 per-smtpd-instance <a href="master.5.html">master.cf</a> overrides of this parameter are not 14614 effective. Note, that each of the cache databases supported by <a href="tlsmgr.8.html">tlsmgr(8)</a> 14615 daemon: $<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a>, $<a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> 14616 (and with Postfix 2.3 and later $<a href="postconf.5.html#lmtp_tls_session_cache_database">lmtp_tls_session_cache_database</a>), needs to be 14617 stored separately. It is not at this time possible to store multiple 14618 caches in a single database. </p> 14619 14620 <p> Note: <b>dbm</b> databases are not suitable. TLS 14621 session objects are too large. </p> 14622 14623 <p> As of version 2.5, Postfix no longer uses root privileges when 14624 opening this file. The file should now be stored under the Postfix-owned 14625 <a href="postconf.5.html#data_directory">data_directory</a>. As a migration aid, an attempt to open the file 14626 under a non-Postfix directory is redirected to the Postfix-owned 14627 <a href="postconf.5.html#data_directory">data_directory</a>, and a warning is logged. </p> 14628 14629 <p> Example: </p> 14630 14631 <pre> 14632 <a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> = btree:/var/db/postfix/smtpd_scache 14633 </pre> 14634 14635 <p> This feature is available in Postfix 2.2 and later. </p> 14636 14637 14638 </DD> 14639 14640 <DT><b><a name="smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a> 14641 (default: 3600s)</b></DT><DD> 14642 14643 <p> The expiration time of Postfix SMTP server TLS session cache 14644 information. A cache cleanup is performed periodically 14645 every $<a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a> seconds. As with 14646 $<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a>, this parameter is implemented in the 14647 <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon and therefore per-smtpd-instance <a href="master.5.html">master.cf</a> overrides 14648 are not possible. </p> 14649 14650 <p> This feature is available in Postfix 2.2 and later. </p> 14651 14652 14653 </DD> 14654 14655 <DT><b><a name="smtpd_tls_wrappermode">smtpd_tls_wrappermode</a> 14656 (default: no)</b></DT><DD> 14657 14658 <p> Run the Postfix SMTP server in the non-standard "wrapper" mode, 14659 instead of using the STARTTLS command. </p> 14660 14661 <p> If you want to support this service, enable a special port in 14662 <a href="master.5.html">master.cf</a>, and specify "-o <a href="postconf.5.html#smtpd_tls_wrappermode">smtpd_tls_wrappermode</a>=yes" on the SMTP 14663 server's command line. Port 465 (smtps) was once chosen for this 14664 purpose. </p> 14665 14666 <p> This feature is available in Postfix 2.2 and later. </p> 14667 14668 14669 </DD> 14670 14671 <DT><b><a name="smtpd_use_tls">smtpd_use_tls</a> 14672 (default: no)</b></DT><DD> 14673 14674 <p> Opportunistic TLS: announce STARTTLS support to SMTP clients, 14675 but do not require that clients use TLS encryption. </p> 14676 14677 <p> Note: when invoked via "<b>sendmail -bs</b>", Postfix will never offer 14678 STARTTLS due to insufficient privileges to access the server private 14679 key. This is intended behavior. </p> 14680 14681 <p> This feature is available in Postfix 2.2 and later. With 14682 Postfix 2.3 and later use <a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> instead. </p> 14683 14684 14685 </DD> 14686 14687 <DT><b><a name="soft_bounce">soft_bounce</a> 14688 (default: no)</b></DT><DD> 14689 14690 <p> 14691 Safety net to keep mail queued that would otherwise be returned to 14692 the sender. This parameter disables locally-generated bounces, 14693 and prevents the Postfix SMTP server from rejecting mail permanently, 14694 by changing 5xx reply codes into 4xx. However, <a href="postconf.5.html#soft_bounce">soft_bounce</a> is no 14695 cure for address rewriting mistakes or mail routing mistakes. 14696 </p> 14697 14698 <p> 14699 Example: 14700 </p> 14701 14702 <pre> 14703 <a href="postconf.5.html#soft_bounce">soft_bounce</a> = yes 14704 </pre> 14705 14706 14707 </DD> 14708 14709 <DT><b><a name="stale_lock_time">stale_lock_time</a> 14710 (default: 500s)</b></DT><DD> 14711 14712 <p> 14713 The time after which a stale exclusive mailbox lockfile is removed. 14714 This is used for delivery to file or mailbox. 14715 </p> 14716 14717 <p> 14718 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 14719 The default time unit is s (seconds). 14720 </p> 14721 14722 14723 </DD> 14724 14725 <DT><b><a name="stress">stress</a> 14726 (default: empty)</b></DT><DD> 14727 14728 <p> This feature is documented in the <a href="STRESS_README.html">STRESS_README</a> document. </p> 14729 14730 <p> This feature is available in Postfix 2.5 and later. </p> 14731 14732 14733 </DD> 14734 14735 <DT><b><a name="strict_7bit_headers">strict_7bit_headers</a> 14736 (default: no)</b></DT><DD> 14737 14738 <p> 14739 Reject mail with 8-bit text in message headers. This blocks mail 14740 from poorly written applications. 14741 </p> 14742 14743 <p> 14744 This feature should not be enabled on a general purpose mail server, 14745 because it is likely to reject legitimate email. 14746 </p> 14747 14748 <p> 14749 This feature is available in Postfix 2.0 and later. 14750 </p> 14751 14752 14753 </DD> 14754 14755 <DT><b><a name="strict_8bitmime">strict_8bitmime</a> 14756 (default: no)</b></DT><DD> 14757 14758 <p> 14759 Enable both <a href="postconf.5.html#strict_7bit_headers">strict_7bit_headers</a> and <a href="postconf.5.html#strict_8bitmime_body">strict_8bitmime_body</a>. 14760 </p> 14761 14762 <p> 14763 This feature should not be enabled on a general purpose mail server, 14764 because it is likely to reject legitimate email. 14765 </p> 14766 14767 <p> 14768 This feature is available in Postfix 2.0 and later. 14769 </p> 14770 14771 14772 </DD> 14773 14774 <DT><b><a name="strict_8bitmime_body">strict_8bitmime_body</a> 14775 (default: no)</b></DT><DD> 14776 14777 <p> 14778 Reject 8-bit message body text without 8-bit MIME content encoding 14779 information. This blocks mail from poorly written applications. 14780 </p> 14781 14782 <p> 14783 Unfortunately, this also rejects majordomo approval requests when 14784 the included request contains valid 8-bit MIME mail, and it rejects 14785 bounces from mailers that do not MIME encapsulate 8-bit content 14786 (for example, bounces from qmail or from old versions of Postfix). 14787 </p> 14788 14789 <p> 14790 This feature should not be enabled on a general purpose mail server, 14791 because it is likely to reject legitimate email. 14792 </p> 14793 14794 <p> 14795 This feature is available in Postfix 2.0 and later. 14796 </p> 14797 14798 14799 </DD> 14800 14801 <DT><b><a name="strict_mailbox_ownership">strict_mailbox_ownership</a> 14802 (default: yes)</b></DT><DD> 14803 14804 <p> Defer delivery when a mailbox file is not owned by its recipient. 14805 The default setting is not backwards compatible. </p> 14806 14807 <p> This feature is available in Postfix 2.5.3 and later. </p> 14808 14809 14810 </DD> 14811 14812 <DT><b><a name="strict_mime_encoding_domain">strict_mime_encoding_domain</a> 14813 (default: no)</b></DT><DD> 14814 14815 <p> 14816 Reject mail with invalid Content-Transfer-Encoding: information 14817 for the message/* or multipart/* MIME content types. This blocks 14818 mail from poorly written software. 14819 </p> 14820 14821 <p> 14822 This feature should not be enabled on a general purpose mail server, 14823 because it will reject mail after a single violation. 14824 </p> 14825 14826 <p> 14827 This feature is available in Postfix 2.0 and later. 14828 </p> 14829 14830 14831 </DD> 14832 14833 <DT><b><a name="strict_rfc821_envelopes">strict_rfc821_envelopes</a> 14834 (default: no)</b></DT><DD> 14835 14836 <p> 14837 Require that addresses received in SMTP MAIL FROM and RCPT TO 14838 commands are enclosed with <>, and that those addresses do 14839 not contain <a href="http://tools.ietf.org/html/rfc822">RFC 822</a> style comments or phrases. This stops mail 14840 from poorly written software. 14841 </p> 14842 14843 <p> 14844 By default, the Postfix SMTP server accepts <a href="http://tools.ietf.org/html/rfc822">RFC 822</a> syntax in MAIL 14845 FROM and RCPT TO addresses. 14846 </p> 14847 14848 14849 </DD> 14850 14851 <DT><b><a name="sun_mailtool_compatibility">sun_mailtool_compatibility</a> 14852 (default: no)</b></DT><DD> 14853 14854 <p> 14855 Obsolete SUN mailtool compatibility feature. Instead, use 14856 "<a href="postconf.5.html#mailbox_delivery_lock">mailbox_delivery_lock</a> = dotlock". 14857 </p> 14858 14859 14860 </DD> 14861 14862 <DT><b><a name="swap_bangpath">swap_bangpath</a> 14863 (default: yes)</b></DT><DD> 14864 14865 <p> 14866 Enable the rewriting of "site!user" into "user@site". This is 14867 necessary if your machine is connected to UUCP networks. It is 14868 enabled by default. 14869 </p> 14870 14871 <p> Note: with Postfix version 2.2, message header address rewriting 14872 happens only when one of the following conditions is true: </p> 14873 14874 <ul> 14875 14876 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 14877 14878 <li> The message is received from a network client that matches 14879 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 14880 14881 <li> The message is received from the network, and the 14882 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 14883 14884 </ul> 14885 14886 <p> To get the behavior before Postfix version 2.2, specify 14887 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 14888 14889 <p> 14890 Example: 14891 </p> 14892 14893 <pre> 14894 <a href="postconf.5.html#swap_bangpath">swap_bangpath</a> = no 14895 </pre> 14896 14897 14898 </DD> 14899 14900 <DT><b><a name="syslog_facility">syslog_facility</a> 14901 (default: mail)</b></DT><DD> 14902 14903 <p> 14904 The syslog facility of Postfix logging. Specify a facility as 14905 defined in syslog.conf(5). The default facility is "mail". 14906 </p> 14907 14908 <p> 14909 Warning: a non-default <a href="postconf.5.html#syslog_facility">syslog_facility</a> setting takes effect only 14910 after a Postfix process has completed initialization. Errors during 14911 process initialization will be logged with the default facility. 14912 Examples are errors while parsing the command line arguments, and 14913 errors while accessing the Postfix <a href="postconf.5.html">main.cf</a> configuration file. 14914 </p> 14915 14916 14917 </DD> 14918 14919 <DT><b><a name="syslog_name">syslog_name</a> 14920 (default: see "postconf -d" output)</b></DT><DD> 14921 14922 <p> 14923 The mail system name that is prepended to the process name in syslog 14924 records, so that "smtpd" becomes, for example, "postfix/smtpd". 14925 </p> 14926 14927 <p> 14928 Warning: a non-default <a href="postconf.5.html#syslog_name">syslog_name</a> setting takes effect only after 14929 a Postfix process has completed initialization. Errors during 14930 process initialization will be logged with the default name. Examples 14931 are errors while parsing the command line arguments, and errors 14932 while accessing the Postfix <a href="postconf.5.html">main.cf</a> configuration file. 14933 </p> 14934 14935 14936 </DD> 14937 14938 <DT><b><a name="tcp_windowsize">tcp_windowsize</a> 14939 (default: 0)</b></DT><DD> 14940 14941 <p> An optional workaround for routers that break TCP window scaling. 14942 Specify a value > 0 and < 65536 to enable this feature. With 14943 Postfix TCP servers (<a href="smtpd.8.html">smtpd(8)</a>, <a href="qmqpd.8.html">qmqpd(8)</a>), this feature is implemented 14944 by the Postfix <a href="master.8.html">master(8)</a> daemon. </p> 14945 14946 <p> To change this parameter without stopping Postfix, you need to 14947 first terminate all Postfix TCP servers: </p> 14948 14949 <blockquote> 14950 <pre> 14951 # postconf -e <a href="postconf.5.html#master_service_disable">master_service_disable</a>=inet 14952 # postfix reload 14953 </pre> 14954 </blockquote> 14955 14956 <p> This immediately terminates all processes that accept network 14957 connections. Next, you enable Postfix TCP servers with the updated 14958 <a href="postconf.5.html#tcp_windowsize">tcp_windowsize</a> setting: </p> 14959 14960 <blockquote> 14961 <pre> 14962 # postconf -e <a href="postconf.5.html#tcp_windowsize">tcp_windowsize</a>=65535 <a href="postconf.5.html#master_service_disable">master_service_disable</a>= 14963 # postfix reload 14964 </pre> 14965 </blockquote> 14966 14967 <p> If you skip these steps with a running Postfix system, then the 14968 <a href="postconf.5.html#tcp_windowsize">tcp_windowsize</a> change will work only for Postfix TCP clients (<a href="smtp.8.html">smtp(8)</a>, 14969 <a href="lmtp.8.html">lmtp(8)</a>). </p> 14970 14971 <p> This feature is available in Postfix 2.6 and later. </p> 14972 14973 14974 </DD> 14975 14976 <DT><b><a name="tls_append_default_CA">tls_append_default_CA</a> 14977 (default: no)</b></DT><DD> 14978 14979 <p> Append the system-supplied default certificate authority 14980 certificates to the ones specified with *_tls_CApath or *_tls_CAfile. 14981 The default is "no"; this prevents Postfix from trusting third-party 14982 certificates and giving them relay permission with 14983 <a href="postconf.5.html#permit_tls_all_clientcerts">permit_tls_all_clientcerts</a>. </p> 14984 14985 <p> This feature is available in Postfix 2.4.15, 2.5.11, 2.6.8, 14986 2.7.2 and later versions. Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = yes" for 14987 backwards compatibility, to avoid breaking certificate verification 14988 with sites that don't use <a href="postconf.5.html#permit_tls_all_clientcerts">permit_tls_all_clientcerts</a>. </p> 14989 14990 14991 </DD> 14992 14993 <DT><b><a name="tls_daemon_random_bytes">tls_daemon_random_bytes</a> 14994 (default: 32)</b></DT><DD> 14995 14996 <p> The number of pseudo-random bytes that an <a href="smtp.8.html">smtp(8)</a> or <a href="smtpd.8.html">smtpd(8)</a> 14997 process requests from the <a href="tlsmgr.8.html">tlsmgr(8)</a> server in order to seed its 14998 internal pseudo random number generator (PRNG). The default of 32 14999 bytes (equivalent to 256 bits) is sufficient to generate a 128bit 15000 (or 168bit) session key. </p> 15001 15002 <p> This feature is available in Postfix 2.2 and later. </p> 15003 15004 15005 </DD> 15006 15007 <DT><b><a name="tls_disable_workarounds">tls_disable_workarounds</a> 15008 (default: see "postconf -d" output)</b></DT><DD> 15009 15010 <p> List or bit-mask of OpenSSL bug work-arounds to disable. </p> 15011 15012 <p> The OpenSSL toolkit includes a set of work-arounds for buggy SSL/TLS 15013 implementations. Applications, such as Postfix, that want to maximize 15014 interoperability ask the OpenSSL library to enable the full set of 15015 recommended work-arounds. </p> 15016 15017 <p> From time to time, it is discovered that a work-around creates a 15018 security issue, and should no longer be used. If upgrading OpenSSL 15019 to a fixed version is not an option or an upgrade is not available 15020 in a timely manner, or in closed environments where no buggy clients 15021 or servers exist, it may be appropriate to disable some or all of the 15022 OpenSSL interoperability work-arounds. This parameter specifies which 15023 bug work-arounds to disable. </p> 15024 15025 <p> If the value of the parameter is a hexadecimal long integer starting 15026 with "0x", the bug work-arounds corresponding to the bits specified in 15027 its value are removed from the <b>SSL_OP_ALL</b> work-around bit-mask 15028 (see openssl/ssl.h and SSL_CTX_set_options(3)). You can specify more 15029 bits than are present in SSL_OP_ALL, excess bits are ignored. Specifying 15030 0xFFFFFFFF disables all bug-workarounds on a 32-bit system. This should 15031 also be sufficient on 64-bit systems, until OpenSSL abandons support 15032 for 32-bit systems and starts using the high 32 bits of a 64-bit 15033 bug-workaround mask. </p> 15034 15035 <p> Otherwise, the parameter is a white-space or comma separated list 15036 of specific named bug work-arounds chosen from the list below. It 15037 is possible that your OpenSSL version includes new bug work-arounds 15038 added after your Postfix source code was last updated, in that case 15039 you can only disable one of these via the hexadecimal syntax above. </p> 15040 15041 <dl> 15042 15043 <dt><b>MICROSOFT_SESS_ID_BUG</b></dt> <dd>See SSL_CTX_set_options(3)</dd> 15044 15045 <dt><b>NETSCAPE_CHALLENGE_BUG</b></dt> <dd>See SSL_CTX_set_options(3)</dd> 15046 15047 <dt><b>LEGACY_SERVER_CONNECT</b></dt> <dd>See SSL_CTX_set_options(3)</dd> 15048 15049 <dt><b>NETSCAPE_REUSE_CIPHER_CHANGE_BUG</b></dt> <dd> also aliased 15050 as <b>CVE-2010-4180</b>. Postfix 2.8 disables this work-around by 15051 default with OpenSSL versions that may predate the fix. Fixed in 15052 OpenSSL 0.9.8q and OpenSSL 1.0.0c.</dd> 15053 15054 <dt><b>SSLREF2_REUSE_CERT_TYPE_BUG</b></dt> <dd>See 15055 SSL_CTX_set_options(3)</dd> 15056 15057 <dt><b>MICROSOFT_BIG_SSLV3_BUFFER</b></dt> <dd>See 15058 SSL_CTX_set_options(3)</dd> 15059 15060 <dt><b>MSIE_SSLV2_RSA_PADDING</b></dt> <dd> also aliased as 15061 <b>CVE-2005-2969</b>. Postfix 2.8 disables this work-around by 15062 default with OpenSSL versions that may predate the fix. Fixed in 15063 OpenSSL 0.9.7h and OpenSSL 0.9.8a.</dd> 15064 15065 <dt><b>SSLEAY_080_CLIENT_DH_BUG</b></dt> <dd>See 15066 SSL_CTX_set_options(3)</dd> 15067 15068 <dt><b>TLS_D5_BUG</b></dt> <dd>See SSL_CTX_set_options(3)</dd> 15069 15070 <dt><b>TLS_BLOCK_PADDING_BUG</b></dt> <dd>See SSL_CTX_set_options(3)</dd> 15071 15072 <dt><b>TLS_ROLLBACK_BUG</b></dt> <dd>See SSL_CTX_set_options(3). 15073 This is disabled in OpenSSL 0.9.7 and later. Nobody should still 15074 be using 0.9.6! </dd> 15075 15076 <dt><b>DONT_INSERT_EMPTY_FRAGMENTS</b></dt> <dd>See 15077 SSL_CTX_set_options(3)</dd> 15078 15079 <dt><b>CRYPTOPRO_TLSEXT_BUG</b></dt> <dd>New with GOST support in 15080 OpenSSL 1.0.0.</dd> 15081 15082 </dl> 15083 15084 <p> This feature is available in Postfix 2.8 and later. </p> 15085 15086 15087 </DD> 15088 15089 <DT><b><a name="tls_eecdh_strong_curve">tls_eecdh_strong_curve</a> 15090 (default: prime256v1)</b></DT><DD> 15091 15092 <p> The elliptic curve used by the SMTP server for sensibly strong 15093 ephemeral ECDH key exchange. This curve is used by the Postfix SMTP 15094 server when "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = strong". The phrase "sensibly 15095 strong" means approximately 128-bit security based on best known 15096 attacks. The selected curve must be implemented by OpenSSL (as 15097 reported by ecparam(1) with the "-list_curves" option) and be one 15098 of the curves listed in Section 5.1.1 of <a href="http://tools.ietf.org/html/rfc4492">RFC 4492</a>. You should not 15099 generally change this setting. </p> 15100 15101 <p> This default curve is specified in NSA "Suite B" Cryptography 15102 (see <a href="http://www.nsa.gov/ia/industry/crypto_suite_b.cfm">http://www.nsa.gov/ia/industry/crypto_suite_b.cfm</a>) for 15103 information classified as SECRET. </p> 15104 15105 <p> Note: elliptic curve names are poorly standardized; different 15106 standards groups are assigning different names to the same underlying 15107 curves. The curve with the X9.62 name "prime256v1" is also known 15108 under the SECG name "secp256r1", but OpenSSL does not recognize the 15109 latter name. </p> 15110 15111 <p> This feature is available in Postfix 2.6 and later, when it is 15112 compiled and linked with OpenSSL 1.0.0 or later. </p> 15113 15114 15115 </DD> 15116 15117 <DT><b><a name="tls_eecdh_ultra_curve">tls_eecdh_ultra_curve</a> 15118 (default: secp384r1)</b></DT><DD> 15119 15120 <p> The elliptic curve used by the SMTP server for maximally strong 15121 ephemeral ECDH key exchange. This curve is used by the Postfix SMTP 15122 server when "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = ultra". The phrase "maximally 15123 strong" means approximately 192-bit security based on best known attacks. 15124 This additional strength comes at a significant computational cost, most 15125 users should instead set "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = strong". The selected 15126 curve must be implemented by OpenSSL (as reported by ecparam(1) with the 15127 "-list_curves" option) and be one of the curves listed in Section 5.1.1 15128 of <a href="http://tools.ietf.org/html/rfc4492">RFC 4492</a>. You should not generally change this setting. </p> 15129 15130 <p> This default "ultra" curve is specified in NSA "Suite B" Cryptography 15131 (see <a href="http://www.nsa.gov/ia/industry/crypto_suite_b.cfm">http://www.nsa.gov/ia/industry/crypto_suite_b.cfm</a>) for information 15132 classified as TOP SECRET. </p> 15133 15134 <p> This feature is available in Postfix 2.6 and later, when it is 15135 compiled and linked with OpenSSL 1.0.0 or later. </p> 15136 15137 15138 </DD> 15139 15140 <DT><b><a name="tls_export_cipherlist">tls_export_cipherlist</a> 15141 (default: ALL:+RC4:@STRENGTH)</b></DT><DD> 15142 15143 <p> The OpenSSL cipherlist for "EXPORT" or higher grade ciphers. This 15144 defines the meaning of the "export" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, 15145 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. This is 15146 the cipherlist for the opportunistic ("may") TLS client security 15147 level and is the default cipherlist for the SMTP server. You are 15148 strongly encouraged to not change this setting. With OpenSSL 1.0.0 and 15149 later the cipherlist may start with an "aNULL:" prefix, which restores 15150 the 0.9.8-compatible ordering of the aNULL ciphers to the top of the 15151 list when they are enabled. This prefix is not needed with previous 15152 OpenSSL releases. </p> 15153 15154 <p> This feature is available in Postfix 2.3 and later. </p> 15155 15156 15157 </DD> 15158 15159 <DT><b><a name="tls_high_cipherlist">tls_high_cipherlist</a> 15160 (default: ALL:!EXPORT:!LOW:!MEDIUM:+RC4:@STRENGTH)</b></DT><DD> 15161 15162 <p> The OpenSSL cipherlist for "HIGH" grade ciphers. This defines 15163 the meaning of the "high" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, 15164 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are 15165 strongly encouraged to not change this setting. With OpenSSL 1.0.0 and 15166 later the cipherlist may start with an "aNULL:" prefix, which restores 15167 the 0.9.8-compatible ordering of the aNULL ciphers to the top of the 15168 list when they are enabled. This prefix is not needed with previous 15169 OpenSSL releases. </p> 15170 15171 <p> This feature is available in Postfix 2.3 and later. </p> 15172 15173 15174 </DD> 15175 15176 <DT><b><a name="tls_low_cipherlist">tls_low_cipherlist</a> 15177 (default: ALL:!EXPORT:+RC4:@STRENGTH)</b></DT><DD> 15178 15179 <p> The OpenSSL cipherlist for "LOW" or higher grade ciphers. This defines 15180 the meaning of the "low" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, 15181 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are 15182 strongly encouraged to not change this setting. With OpenSSL 1.0.0 and 15183 later the cipherlist may start with an "aNULL:" prefix, which restores 15184 the 0.9.8-compatible ordering of the aNULL ciphers to the top of the 15185 list when they are enabled. This prefix is not needed with previous 15186 OpenSSL releases. </p> 15187 15188 <p> This feature is available in Postfix 2.3 and later. </p> 15189 15190 15191 </DD> 15192 15193 <DT><b><a name="tls_medium_cipherlist">tls_medium_cipherlist</a> 15194 (default: ALL:!EXPORT:!LOW:+RC4:@STRENGTH)</b></DT><DD> 15195 15196 <p> The OpenSSL cipherlist for "MEDIUM" or higher grade ciphers. This 15197 defines the meaning of the "medium" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, 15198 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. This is 15199 the default cipherlist for mandatory TLS encryption in the TLS 15200 client (with anonymous ciphers disabled when verifying server 15201 certificates). You are strongly encouraged to not change this 15202 setting. With OpenSSL 1.0.0 and later the cipherlist may start with an 15203 "aNULL:" prefix, which restores the 0.9.8-compatible ordering of the 15204 aNULL ciphers to the top of the list when they are enabled. This prefix 15205 is not needed with previous OpenSSL releases. </p> 15206 15207 <p> This feature is available in Postfix 2.3 and later. </p> 15208 15209 15210 </DD> 15211 15212 <DT><b><a name="tls_null_cipherlist">tls_null_cipherlist</a> 15213 (default: eNULL:!aNULL)</b></DT><DD> 15214 15215 <p> The OpenSSL cipherlist for "NULL" grade ciphers that provide 15216 authentication without encryption. This defines the meaning of the "null" 15217 setting in smtpd_mandatory_tls_ciphers, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and 15218 <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are strongly encouraged to not 15219 change this setting. </p> 15220 15221 <p> This feature is available in Postfix 2.3 and later. </p> 15222 15223 15224 </DD> 15225 15226 <DT><b><a name="tls_preempt_cipherlist">tls_preempt_cipherlist</a> 15227 (default: no)</b></DT><DD> 15228 15229 <p> With SSLv3 and later, use the server's cipher preference order 15230 instead of the client's cipher preference order. </p> 15231 15232 <p> By default, the OpenSSL server selects the client's most preferred 15233 cipher that the server supports. With SSLv3 and later, the server may 15234 choose its own most preferred cipher that is supported (offered) by 15235 the client. Setting "<a href="postconf.5.html#tls_preempt_cipherlist">tls_preempt_cipherlist</a> = yes" enables server cipher 15236 preferences. </p> 15237 15238 <p> While server cipher selection may in some cases lead to a more secure 15239 or performant cipher choice, there is some risk of interoperability 15240 issues. In the past, some SSL clients have listed lower priority ciphers 15241 that they did not implement correctly. If the server chooses a cipher 15242 that the client prefers less, it may select a cipher whose client 15243 implementation is flawed. </p> 15244 15245 <p> This feature is available in Postfix 2.8 and later, in combination 15246 with OpenSSL 0.9.7 and later. </p> 15247 15248 15249 </DD> 15250 15251 <DT><b><a name="tls_random_bytes">tls_random_bytes</a> 15252 (default: 32)</b></DT><DD> 15253 15254 <p> The number of bytes that <a href="tlsmgr.8.html">tlsmgr(8)</a> reads from $<a href="postconf.5.html#tls_random_source">tls_random_source</a> 15255 when (re)seeding the in-memory pseudo random number generator (PRNG) 15256 pool. The default of 32 bytes (256 bits) is good enough for 128bit 15257 symmetric keys. If using EGD or a device file, a maximum of 255 15258 bytes is read. </p> 15259 15260 <p> This feature is available in Postfix 2.2 and later. </p> 15261 15262 15263 </DD> 15264 15265 <DT><b><a name="tls_random_exchange_name">tls_random_exchange_name</a> 15266 (default: see "postconf -d" output)</b></DT><DD> 15267 15268 <p> Name of the pseudo random number generator (PRNG) state file 15269 that is maintained by <a href="tlsmgr.8.html">tlsmgr(8)</a>. The file is created when it does 15270 not exist, and its length is fixed at 1024 bytes. </p> 15271 15272 <p> As of version 2.5, Postfix no longer uses root privileges when 15273 opening this file, and the default file location was changed from 15274 ${<a href="postconf.5.html#config_directory">config_directory</a>}/prng_exch to ${<a href="postconf.5.html#data_directory">data_directory</a>}/prng_exch. As 15275 a migration aid, an attempt to open the file under a non-Postfix 15276 directory is redirected to the Postfix-owned <a href="postconf.5.html#data_directory">data_directory</a>, and a 15277 warning is logged. </p> 15278 15279 <p> This feature is available in Postfix 2.2 and later. </p> 15280 15281 15282 </DD> 15283 15284 <DT><b><a name="tls_random_prng_update_period">tls_random_prng_update_period</a> 15285 (default: 3600s)</b></DT><DD> 15286 15287 <p> The time between attempts by <a href="tlsmgr.8.html">tlsmgr(8)</a> to save the state of 15288 the pseudo random number generator (PRNG) to the file specified 15289 with $<a href="postconf.5.html#tls_random_exchange_name">tls_random_exchange_name</a>. </p> 15290 15291 <p> This feature is available in Postfix 2.2 and later. </p> 15292 15293 15294 </DD> 15295 15296 <DT><b><a name="tls_random_reseed_period">tls_random_reseed_period</a> 15297 (default: 3600s)</b></DT><DD> 15298 15299 <p> The maximal time between attempts by <a href="tlsmgr.8.html">tlsmgr(8)</a> to re-seed the 15300 in-memory pseudo random number generator (PRNG) pool from external 15301 sources. The actual time between re-seeding attempts is calculated 15302 using the PRNG, and is between 0 and the time specified. </p> 15303 15304 <p> This feature is available in Postfix 2.2 and later. </p> 15305 15306 15307 </DD> 15308 15309 <DT><b><a name="tls_random_source">tls_random_source</a> 15310 (default: see "postconf -d" output)</b></DT><DD> 15311 15312 <p> The external entropy source for the in-memory <a href="tlsmgr.8.html">tlsmgr(8)</a> pseudo 15313 random number generator (PRNG) pool. Be sure to specify a non-blocking 15314 source. If this source is not a regular file, the entropy source 15315 type must be prepended: egd:/path/to/egd_socket for a source with 15316 EGD compatible socket interface, or dev:/path/to/device for a 15317 device file. </p> 15318 15319 <p> Note: on OpenBSD systems specify /dev/arandom when /dev/urandom 15320 gives timeout errors. </p> 15321 15322 <p> This feature is available in Postfix 2.2 and later. </p> 15323 15324 15325 </DD> 15326 15327 <DT><b><a name="tlsproxy_enforce_tls">tlsproxy_enforce_tls</a> 15328 (default: $<a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>)</b></DT><DD> 15329 15330 <p> Mandatory TLS: announce STARTTLS support to SMTP clients, and 15331 require that clients use TLS encryption. See <a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a> for 15332 further details. </p> 15333 15334 <p> This feature is available in Postfix 2.8 and later. </p> 15335 15336 15337 </DD> 15338 15339 <DT><b><a name="tlsproxy_service_name">tlsproxy_service_name</a> 15340 (default: tlsproxy)</b></DT><DD> 15341 15342 <p> The name of the <a href="tlsproxy.8.html">tlsproxy(8)</a> service entry in <a href="master.5.html">master.cf</a>. This 15343 service performs plaintext <=> TLS ciphertext conversion. <p> 15344 15345 <p> This feature is available in Postfix 2.8 and later. </p> 15346 15347 15348 </DD> 15349 15350 <DT><b><a name="tlsproxy_tls_CAfile">tlsproxy_tls_CAfile</a> 15351 (default: $<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>)</b></DT><DD> 15352 15353 <p> A file containing (PEM format) CA certificates of root CAs 15354 trusted to sign either remote SMTP client certificates or intermediate 15355 CA certificates. See <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> for further details. </p> 15356 15357 <p> This feature is available in Postfix 2.8 and later. </p> 15358 15359 15360 </DD> 15361 15362 <DT><b><a name="tlsproxy_tls_CApath">tlsproxy_tls_CApath</a> 15363 (default: $<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>)</b></DT><DD> 15364 15365 <p> A directory containing (PEM format) CA certificates of root CAs 15366 trusted to sign either remote SMTP client certificates or intermediate 15367 CA certificates. See <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> for further details. </p> 15368 15369 <p> This feature is available in Postfix 2.8 and later. </p> 15370 15371 15372 </DD> 15373 15374 <DT><b><a name="tlsproxy_tls_always_issue_session_ids">tlsproxy_tls_always_issue_session_ids</a> 15375 (default: $<a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a>)</b></DT><DD> 15376 15377 <p> Force the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server to issue a TLS session id, 15378 even when TLS session caching is turned off. See 15379 <a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a> for further details. </p> 15380 15381 <p> This feature is available in Postfix 2.8 and later. </p> 15382 15383 15384 </DD> 15385 15386 <DT><b><a name="tlsproxy_tls_ask_ccert">tlsproxy_tls_ask_ccert</a> 15387 (default: $<a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>)</b></DT><DD> 15388 15389 <p> Ask a remote SMTP client for a client certificate. See 15390 <a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a> for further details. </p> 15391 15392 <p> This feature is available in Postfix 2.8 and later. </p> 15393 15394 15395 </DD> 15396 15397 <DT><b><a name="tlsproxy_tls_ccert_verifydepth">tlsproxy_tls_ccert_verifydepth</a> 15398 (default: $<a href="postconf.5.html#smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a>)</b></DT><DD> 15399 15400 <p> The verification depth for remote SMTP client certificates. A 15401 depth of 1 is sufficient if the issuing CA is listed in a local CA 15402 file. See <a href="postconf.5.html#smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a> for further details. </p> 15403 15404 <p> This feature is available in Postfix 2.8 and later. </p> 15405 15406 15407 </DD> 15408 15409 <DT><b><a name="tlsproxy_tls_cert_file">tlsproxy_tls_cert_file</a> 15410 (default: $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>)</b></DT><DD> 15411 15412 <p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server RSA certificate in PEM 15413 format. This file may also contain the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server 15414 private RSA key. See <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> for further details. </p> 15415 15416 <p> This feature is available in Postfix 2.8 and later. </p> 15417 15418 15419 </DD> 15420 15421 <DT><b><a name="tlsproxy_tls_ciphers">tlsproxy_tls_ciphers</a> 15422 (default: $<a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>)</b></DT><DD> 15423 15424 <p> The minimum TLS cipher grade that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server 15425 will use with opportunistic TLS encryption. See <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> 15426 for further details. </p> 15427 15428 <p> This feature is available in Postfix 2.8 and later. </p> 15429 15430 15431 </DD> 15432 15433 <DT><b><a name="tlsproxy_tls_dcert_file">tlsproxy_tls_dcert_file</a> 15434 (default: $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>)</b></DT><DD> 15435 15436 <p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server DSA certificate in PEM 15437 format. This file may also contain the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server 15438 private DSA key. See <a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a> for further details. 15439 </p> 15440 15441 <p> This feature is available in Postfix 2.8 and later. </p> 15442 15443 15444 </DD> 15445 15446 <DT><b><a name="tlsproxy_tls_dh1024_param_file">tlsproxy_tls_dh1024_param_file</a> 15447 (default: $<a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a>)</b></DT><DD> 15448 15449 <p> File with DH parameters that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server 15450 should use with EDH ciphers. See <a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a> for 15451 further details. </p> 15452 15453 <p> This feature is available in Postfix 2.8 and later. </p> 15454 15455 15456 </DD> 15457 15458 <DT><b><a name="tlsproxy_tls_dh512_param_file">tlsproxy_tls_dh512_param_file</a> 15459 (default: $<a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a>)</b></DT><DD> 15460 15461 <p> File with DH parameters that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server 15462 should use with EDH ciphers. See <a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a> for 15463 further details. </p> 15464 15465 <p> This feature is available in Postfix 2.8 and later. </p> 15466 15467 15468 </DD> 15469 15470 <DT><b><a name="tlsproxy_tls_dkey_file">tlsproxy_tls_dkey_file</a> 15471 (default: $<a href="postconf.5.html#smtpd_tls_dkey_file">smtpd_tls_dkey_file</a>)</b></DT><DD> 15472 15473 <p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server DSA private key in PEM 15474 format. This file may be combined with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> 15475 server DSA certificate file specified with $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>. 15476 See <a href="postconf.5.html#smtpd_tls_dkey_file">smtpd_tls_dkey_file</a> for further details. </p> 15477 15478 <p> This feature is available in Postfix 2.8 and later. </p> 15479 15480 15481 </DD> 15482 15483 <DT><b><a name="tlsproxy_tls_eccert_file">tlsproxy_tls_eccert_file</a> 15484 (default: $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>)</b></DT><DD> 15485 15486 <p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server ECDSA certificate in 15487 PEM format. This file may also contain the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> 15488 server private ECDSA key. See <a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a> for further 15489 details. </p> 15490 15491 <p> This feature is available in Postfix 2.8 and later. </p> 15492 15493 15494 </DD> 15495 15496 <DT><b><a name="tlsproxy_tls_eckey_file">tlsproxy_tls_eckey_file</a> 15497 (default: $<a href="postconf.5.html#smtpd_tls_eckey_file">smtpd_tls_eckey_file</a>)</b></DT><DD> 15498 15499 <p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server ECDSA private key in 15500 PEM format. This file may be combined with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> 15501 server ECDSA certificate file specified with $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>. 15502 See <a href="postconf.5.html#smtpd_tls_eckey_file">smtpd_tls_eckey_file</a> for further details. </p> 15503 15504 <p> This feature is available in Postfix 2.8 and later. </p> 15505 15506 15507 </DD> 15508 15509 <DT><b><a name="tlsproxy_tls_eecdh_grade">tlsproxy_tls_eecdh_grade</a> 15510 (default: $<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a>)</b></DT><DD> 15511 15512 <p> The Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server security grade for ephemeral 15513 elliptic-curve Diffie-Hellman (EECDH) key exchange. See 15514 <a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> for further details. </p> 15515 15516 <p> This feature is available in Postfix 2.8 and later. </p> 15517 15518 15519 </DD> 15520 15521 <DT><b><a name="tlsproxy_tls_exclude_ciphers">tlsproxy_tls_exclude_ciphers</a> 15522 (default: $<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a>)</b></DT><DD> 15523 15524 <p> List of ciphers or cipher types to exclude from the <a href="tlsproxy.8.html">tlsproxy(8)</a> 15525 server cipher list at all TLS security levels. See 15526 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> for further details. </p> 15527 15528 <p> This feature is available in Postfix 2.8 and later. </p> 15529 15530 15531 </DD> 15532 15533 <DT><b><a name="tlsproxy_tls_fingerprint_digest">tlsproxy_tls_fingerprint_digest</a> 15534 (default: $<a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a>)</b></DT><DD> 15535 15536 <p> The message digest algorithm used to construct client-certificate 15537 fingerprints. See <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> for further details. 15538 </p> 15539 15540 <p> This feature is available in Postfix 2.8 and later. </p> 15541 15542 15543 </DD> 15544 15545 <DT><b><a name="tlsproxy_tls_key_file">tlsproxy_tls_key_file</a> 15546 (default: $<a href="postconf.5.html#smtpd_tls_key_file">smtpd_tls_key_file</a>)</b></DT><DD> 15547 15548 <p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server RSA private key in PEM 15549 format. This file may be combined with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> 15550 server RSA certificate file specified with $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>. 15551 See <a href="postconf.5.html#smtpd_tls_key_file">smtpd_tls_key_file</a> for further details. </p> 15552 15553 <p> This feature is available in Postfix 2.8 and later. </p> 15554 15555 15556 </DD> 15557 15558 <DT><b><a name="tlsproxy_tls_loglevel">tlsproxy_tls_loglevel</a> 15559 (default: $<a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a>)</b></DT><DD> 15560 15561 <p> Enable additional Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server logging of TLS 15562 activity. Each logging level also includes the information that 15563 is logged at a lower logging level. See <a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a> for 15564 further details. </p> 15565 15566 <p> This feature is available in Postfix 2.8 and later. </p> 15567 15568 15569 </DD> 15570 15571 <DT><b><a name="tlsproxy_tls_mandatory_ciphers">tlsproxy_tls_mandatory_ciphers</a> 15572 (default: $<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>)</b></DT><DD> 15573 15574 <p> The minimum TLS cipher grade that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server 15575 will use with mandatory TLS encryption. See <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> 15576 for further details. </p> 15577 15578 <p> This feature is available in Postfix 2.8 and later. </p> 15579 15580 15581 </DD> 15582 15583 <DT><b><a name="tlsproxy_tls_mandatory_exclude_ciphers">tlsproxy_tls_mandatory_exclude_ciphers</a> 15584 (default: $<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a>)</b></DT><DD> 15585 15586 <p> Additional list of ciphers or cipher types to exclude from the 15587 <a href="tlsproxy.8.html">tlsproxy(8)</a> server cipher list at mandatory TLS security levels. 15588 See <a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> for further details. </p> 15589 15590 <p> This feature is available in Postfix 2.8 and later. </p> 15591 15592 15593 </DD> 15594 15595 <DT><b><a name="tlsproxy_tls_mandatory_protocols">tlsproxy_tls_mandatory_protocols</a> 15596 (default: $<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a>)</b></DT><DD> 15597 15598 <p> The SSL/TLS protocols accepted by the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server 15599 with mandatory TLS encryption. If the list is empty, the server 15600 supports all available SSL/TLS protocol versions. See 15601 <a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> for further details. </p> 15602 15603 <p> This feature is available in Postfix 2.8 and later. </p> 15604 15605 15606 </DD> 15607 15608 <DT><b><a name="tlsproxy_tls_protocols">tlsproxy_tls_protocols</a> 15609 (default: $<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a>)</b></DT><DD> 15610 15611 <p> List of TLS protocols that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server will 15612 exclude or include with opportunistic TLS encryption. See 15613 <a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> for further details. </p> 15614 15615 <p> This feature is available in Postfix 2.8 and later. </p> 15616 15617 15618 </DD> 15619 15620 <DT><b><a name="tlsproxy_tls_req_ccert">tlsproxy_tls_req_ccert</a> 15621 (default: $<a href="postconf.5.html#smtpd_tls_req_ccert">smtpd_tls_req_ccert</a>)</b></DT><DD> 15622 15623 <p> With mandatory TLS encryption, require a trusted remote SMTP 15624 client certificate in order to allow TLS connections to proceed. 15625 See <a href="postconf.5.html#smtpd_tls_req_ccert">smtpd_tls_req_ccert</a> for further details. </p> 15626 15627 <p> This feature is available in Postfix 2.8 and later. </p> 15628 15629 15630 </DD> 15631 15632 <DT><b><a name="tlsproxy_tls_security_level">tlsproxy_tls_security_level</a> 15633 (default: $<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a>)</b></DT><DD> 15634 15635 <p> The SMTP TLS security level for the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server; 15636 when a non-empty value is specified, this overrides the obsolete 15637 parameters <a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> and <a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>. See 15638 <a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> for further details. </p> 15639 15640 <p> This feature is available in Postfix 2.8 and later. </p> 15641 15642 15643 </DD> 15644 15645 <DT><b><a name="tlsproxy_tls_session_cache_timeout">tlsproxy_tls_session_cache_timeout</a> 15646 (default: $<a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a>)</b></DT><DD> 15647 15648 <p> The expiration time of Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server TLS session 15649 cache information. A cache cleanup is performed periodically every 15650 $<a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a> seconds. See 15651 <a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a> for further details. </p> 15652 15653 <p> This feature is available in Postfix 2.8 and later. </p> 15654 15655 15656 </DD> 15657 15658 <DT><b><a name="tlsproxy_use_tls">tlsproxy_use_tls</a> 15659 (default: $<a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a>)</b></DT><DD> 15660 15661 <p> Opportunistic TLS: announce STARTTLS support to SMTP clients, 15662 but do not require that clients use TLS encryption. See <a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> 15663 for further details. </p> 15664 15665 <p> This feature is available in Postfix 2.8 and later. </p> 15666 15667 15668 </DD> 15669 15670 <DT><b><a name="tlsproxy_watchdog_timeout">tlsproxy_watchdog_timeout</a> 15671 (default: 10s)</b></DT><DD> 15672 15673 <p> How much time a <a href="tlsproxy.8.html">tlsproxy(8)</a> process may take to process local 15674 or remote I/O before it is terminated by a built-in watchdog timer. 15675 This is a safety mechanism that prevents <a href="tlsproxy.8.html">tlsproxy(8)</a> from becoming 15676 non-responsive due to a bug in Postfix itself or in system software. 15677 To avoid false alarms and unnecessary cache corruption this limit 15678 cannot be set under 10s. </p> 15679 15680 <p> Specify a non-zero time value (an integral value plus an optional 15681 one-letter suffix that specifies the time unit). Time units: s 15682 (seconds), m (minutes), h (hours), d (days), w (weeks). </p> 15683 15684 <p> This feature is available in Postfix 2.8. </p> 15685 15686 15687 </DD> 15688 15689 <DT><b><a name="trace_service_name">trace_service_name</a> 15690 (default: trace)</b></DT><DD> 15691 15692 <p> 15693 The name of the trace service. This service is implemented by the 15694 <a href="bounce.8.html">bounce(8)</a> daemon and maintains a record 15695 of mail deliveries and produces a mail delivery report when verbose 15696 delivery is requested with "<b>sendmail -v</b>". 15697 </p> 15698 15699 <p> 15700 This feature is available in Postfix 2.1 and later. 15701 </p> 15702 15703 15704 </DD> 15705 15706 <DT><b><a name="transport_delivery_slot_cost">transport_delivery_slot_cost</a> 15707 (default: $<a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a>)</b></DT><DD> 15708 15709 <p> A transport-specific override for the <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> 15710 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15711 the message delivery transport. </p> 15712 15713 15714 </DD> 15715 15716 <DT><b><a name="transport_delivery_slot_discount">transport_delivery_slot_discount</a> 15717 (default: $<a href="postconf.5.html#default_delivery_slot_discount">default_delivery_slot_discount</a>)</b></DT><DD> 15718 15719 <p> A transport-specific override for the <a href="postconf.5.html#default_delivery_slot_discount">default_delivery_slot_discount</a> 15720 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15721 the message delivery transport. </p> 15722 15723 15724 </DD> 15725 15726 <DT><b><a name="transport_delivery_slot_loan">transport_delivery_slot_loan</a> 15727 (default: $<a href="postconf.5.html#default_delivery_slot_loan">default_delivery_slot_loan</a>)</b></DT><DD> 15728 15729 <p> A transport-specific override for the <a href="postconf.5.html#default_delivery_slot_loan">default_delivery_slot_loan</a> 15730 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15731 the message delivery transport. </p> 15732 15733 15734 </DD> 15735 15736 <DT><b><a name="transport_destination_concurrency_failed_cohort_limit">transport_destination_concurrency_failed_cohort_limit</a> 15737 (default: $<a href="postconf.5.html#default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a>)</b></DT><DD> 15738 15739 <p> A transport-specific override for the 15740 <a href="postconf.5.html#default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a> parameter value, 15741 where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 15742 transport. </p> 15743 15744 <p> This feature is available in Postfix 2.5 and later. </p> 15745 15746 15747 </DD> 15748 15749 <DT><b><a name="transport_destination_concurrency_limit">transport_destination_concurrency_limit</a> 15750 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 15751 15752 <p> A transport-specific override for the 15753 <a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a> parameter value, where 15754 <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 15755 transport. </p> 15756 15757 15758 </DD> 15759 15760 <DT><b><a name="transport_destination_concurrency_negative_feedback">transport_destination_concurrency_negative_feedback</a> 15761 (default: $<a href="postconf.5.html#default_destination_concurrency_negative_feedback">default_destination_concurrency_negative_feedback</a>)</b></DT><DD> 15762 15763 <p> A transport-specific override for the 15764 <a href="postconf.5.html#default_destination_concurrency_negative_feedback">default_destination_concurrency_negative_feedback</a> parameter value, 15765 where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 15766 transport. </p> 15767 15768 <p> This feature is available in Postfix 2.5 and later. </p> 15769 15770 15771 </DD> 15772 15773 <DT><b><a name="transport_destination_concurrency_positive_feedback">transport_destination_concurrency_positive_feedback</a> 15774 (default: $<a href="postconf.5.html#default_destination_concurrency_positive_feedback">default_destination_concurrency_positive_feedback</a>)</b></DT><DD> 15775 15776 <p> A transport-specific override for the 15777 <a href="postconf.5.html#default_destination_concurrency_positive_feedback">default_destination_concurrency_positive_feedback</a> parameter value, 15778 where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 15779 transport. </p> 15780 15781 <p> This feature is available in Postfix 2.5 and later. </p> 15782 15783 15784 </DD> 15785 15786 <DT><b><a name="transport_destination_rate_delay">transport_destination_rate_delay</a> 15787 (default: $<a href="postconf.5.html#default_destination_rate_delay">default_destination_rate_delay</a>)</b></DT><DD> 15788 15789 <p> A transport-specific override for the <a href="postconf.5.html#default_destination_rate_delay">default_destination_rate_delay</a> 15790 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15791 the message delivery transport. </p> 15792 15793 <p> This feature is available in Postfix 2.5 and later. </p> 15794 15795 15796 </DD> 15797 15798 <DT><b><a name="transport_destination_recipient_limit">transport_destination_recipient_limit</a> 15799 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 15800 15801 <p> A transport-specific override for the 15802 <a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a> parameter value, where 15803 <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 15804 transport. </p> 15805 15806 15807 </DD> 15808 15809 <DT><b><a name="transport_extra_recipient_limit">transport_extra_recipient_limit</a> 15810 (default: $<a href="postconf.5.html#default_extra_recipient_limit">default_extra_recipient_limit</a>)</b></DT><DD> 15811 15812 <p> A transport-specific override for the <a href="postconf.5.html#default_extra_recipient_limit">default_extra_recipient_limit</a> 15813 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15814 the message delivery transport. </p> 15815 15816 15817 </DD> 15818 15819 <DT><b><a name="transport_initial_destination_concurrency">transport_initial_destination_concurrency</a> 15820 (default: $<a href="postconf.5.html#initial_destination_concurrency">initial_destination_concurrency</a>)</b></DT><DD> 15821 15822 <p> A transport-specific override for the <a href="postconf.5.html#initial_destination_concurrency">initial_destination_concurrency</a> 15823 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15824 the message delivery transport. </p> 15825 15826 <p> This feature is available in Postfix 2.5 and later. </p> 15827 15828 15829 </DD> 15830 15831 <DT><b><a name="transport_maps">transport_maps</a> 15832 (default: empty)</b></DT><DD> 15833 15834 <p> 15835 Optional lookup tables with mappings from recipient address to 15836 (message delivery transport, next-hop destination). See <a href="transport.5.html">transport(5)</a> 15837 for details. 15838 </p> 15839 15840 <p> 15841 Specify zero or more "<a href="DATABASE_README.html">type:table</a>" lookup tables. If you use this 15842 feature with local files, run "<b>postmap /etc/postfix/transport</b>" 15843 after making a change. </p> 15844 15845 <p> For safety reasons, as of Postfix 2.3 this feature does not 15846 allow $number substitutions in regular expression maps. </p> 15847 15848 <p> 15849 Examples: 15850 </p> 15851 15852 <pre> 15853 <a href="postconf.5.html#transport_maps">transport_maps</a> = dbm:/etc/postfix/transport 15854 <a href="postconf.5.html#transport_maps">transport_maps</a> = hash:/etc/postfix/transport 15855 </pre> 15856 15857 15858 </DD> 15859 15860 <DT><b><a name="transport_minimum_delivery_slots">transport_minimum_delivery_slots</a> 15861 (default: $<a href="postconf.5.html#default_minimum_delivery_slots">default_minimum_delivery_slots</a>)</b></DT><DD> 15862 15863 <p> A transport-specific override for the <a href="postconf.5.html#default_minimum_delivery_slots">default_minimum_delivery_slots</a> 15864 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15865 the message delivery transport. </p> 15866 15867 15868 </DD> 15869 15870 <DT><b><a name="transport_recipient_limit">transport_recipient_limit</a> 15871 (default: $<a href="postconf.5.html#default_recipient_limit">default_recipient_limit</a>)</b></DT><DD> 15872 15873 <p> A transport-specific override for the <a href="postconf.5.html#default_recipient_limit">default_recipient_limit</a> 15874 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15875 the message delivery transport. </p> 15876 15877 15878 </DD> 15879 15880 <DT><b><a name="transport_recipient_refill_delay">transport_recipient_refill_delay</a> 15881 (default: $<a href="postconf.5.html#default_recipient_refill_delay">default_recipient_refill_delay</a>)</b></DT><DD> 15882 15883 <p> A transport-specific override for the <a href="postconf.5.html#default_recipient_refill_delay">default_recipient_refill_delay</a> 15884 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15885 the message delivery transport. </p> 15886 15887 <p> This feature is available in Postfix 2.4 and later. </p> 15888 15889 15890 </DD> 15891 15892 <DT><b><a name="transport_recipient_refill_limit">transport_recipient_refill_limit</a> 15893 (default: $<a href="postconf.5.html#default_recipient_refill_limit">default_recipient_refill_limit</a>)</b></DT><DD> 15894 15895 <p> A transport-specific override for the <a href="postconf.5.html#default_recipient_refill_limit">default_recipient_refill_limit</a> 15896 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 15897 the message delivery transport. </p> 15898 15899 <p> This feature is available in Postfix 2.4 and later. </p> 15900 15901 15902 </DD> 15903 15904 <DT><b><a name="transport_retry_time">transport_retry_time</a> 15905 (default: 60s)</b></DT><DD> 15906 15907 <p> 15908 The time between attempts by the Postfix queue manager to contact 15909 a malfunctioning message delivery transport. 15910 </p> 15911 15912 <p> 15913 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 15914 The default time unit is s (seconds). 15915 </p> 15916 15917 15918 </DD> 15919 15920 <DT><b><a name="transport_time_limit">transport_time_limit</a> 15921 (default: $<a href="postconf.5.html#command_time_limit">command_time_limit</a>)</b></DT><DD> 15922 15923 <p> A transport-specific override for the <a href="postconf.5.html#command_time_limit">command_time_limit</a> parameter 15924 value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message 15925 delivery transport. </p> 15926 15927 15928 </DD> 15929 15930 <DT><b><a name="trigger_timeout">trigger_timeout</a> 15931 (default: 10s)</b></DT><DD> 15932 15933 <p> 15934 The time limit for sending a trigger to a Postfix daemon (for 15935 example, the <a href="pickup.8.html">pickup(8)</a> or <a href="qmgr.8.html">qmgr(8)</a> daemon). This time limit prevents 15936 programs from getting stuck when the mail system is under heavy 15937 load. 15938 </p> 15939 15940 <p> 15941 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 15942 The default time unit is s (seconds). 15943 </p> 15944 15945 15946 </DD> 15947 15948 <DT><b><a name="undisclosed_recipients_header">undisclosed_recipients_header</a> 15949 (default: see "postconf -d" output)</b></DT><DD> 15950 15951 <p> 15952 Message header that the Postfix <a href="cleanup.8.html">cleanup(8)</a> server inserts when a 15953 message contains no To: or Cc: message header. With Postfix 2.8 15954 and later, the default value is empty. With Postfix 2.4-2.7, 15955 specify an empty value to disable this feature. </p> 15956 15957 <p> Example: </p> 15958 15959 <pre> 15960 # Default value before Postfix 2.8. 15961 # Note: the ":" and ";" are both required. 15962 <a href="postconf.5.html#undisclosed_recipients_header">undisclosed_recipients_header</a> = To: undisclosed-recipients:; 15963 </pre> 15964 15965 15966 </DD> 15967 15968 <DT><b><a name="unknown_address_reject_code">unknown_address_reject_code</a> 15969 (default: 450)</b></DT><DD> 15970 15971 <p> 15972 The numerical Postfix SMTP server response code when a sender or 15973 recipient address is rejected by the <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a> 15974 or <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a> restriction. The response is 15975 always 450 in case of a temporary DNS error. 15976 </p> 15977 15978 <p> 15979 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 15980 </p> 15981 15982 15983 </DD> 15984 15985 <DT><b><a name="unknown_address_tempfail_action">unknown_address_tempfail_action</a> 15986 (default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD> 15987 15988 <p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a> 15989 or <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a> fail due to a temporary error 15990 condition. Specify "defer" to defer the remote SMTP client request 15991 immediately. With the default "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix 15992 SMTP server continues to look for opportunities to reject mail, and 15993 defers the client request only if it would otherwise be accepted. 15994 </p> 15995 15996 <p> This feature is available in Postfix 2.6 and later. </p> 15997 15998 15999 </DD> 16000 16001 <DT><b><a name="unknown_client_reject_code">unknown_client_reject_code</a> 16002 (default: 450)</b></DT><DD> 16003 16004 <p> 16005 The numerical Postfix SMTP server response code when a client 16006 without valid address <=> name mapping is rejected by the 16007 <a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> restriction. The SMTP server always replies 16008 with 450 when the mapping failed due to a temporary error condition. 16009 </p> 16010 16011 <p> 16012 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 16013 </p> 16014 16015 16016 </DD> 16017 16018 <DT><b><a name="unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a> 16019 (default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD> 16020 16021 <p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> 16022 fails due to an temporary error condition. Specify "defer" to defer 16023 the remote SMTP client request immediately. With the default 16024 "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look 16025 for opportunities to reject mail, and defers the client request 16026 only if it would otherwise be accepted. </p> 16027 16028 <p> This feature is available in Postfix 2.6 and later. </p> 16029 16030 16031 </DD> 16032 16033 <DT><b><a name="unknown_hostname_reject_code">unknown_hostname_reject_code</a> 16034 (default: 450)</b></DT><DD> 16035 16036 <p> 16037 The numerical Postfix SMTP server response code when the hostname 16038 specified with the HELO or EHLO command is rejected by the 16039 <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> restriction. 16040 </p> 16041 16042 <p> 16043 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 16044 </p> 16045 16046 16047 </DD> 16048 16049 <DT><b><a name="unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> 16050 (default: 550)</b></DT><DD> 16051 16052 <p> 16053 The numerical Postfix SMTP server response code when a recipient 16054 address is local, and $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> specifies a list of 16055 lookup tables that does not match the recipient. A recipient 16056 address is local when its domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, 16057 $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> or $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>. 16058 </p> 16059 16060 <p> 16061 The default setting is 550 (reject mail) but it is safer to initially 16062 use 450 (try again later) so you have time to find out if your 16063 <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> settings are OK. 16064 </p> 16065 16066 <p> 16067 Example: 16068 </p> 16069 16070 <pre> 16071 <a href="postconf.5.html#unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> = 450 16072 </pre> 16073 16074 <p> 16075 This feature is available in Postfix 2.0 and later. 16076 </p> 16077 16078 16079 </DD> 16080 16081 <DT><b><a name="unknown_relay_recipient_reject_code">unknown_relay_recipient_reject_code</a> 16082 (default: 550)</b></DT><DD> 16083 16084 <p> 16085 The numerical Postfix SMTP server reply code when a recipient 16086 address matches $<a href="postconf.5.html#relay_domains">relay_domains</a>, and <a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> specifies 16087 a list of lookup tables that does not match the recipient address. 16088 </p> 16089 16090 <p> 16091 This feature is available in Postfix 2.0 and later. 16092 </p> 16093 16094 16095 </DD> 16096 16097 <DT><b><a name="unknown_virtual_alias_reject_code">unknown_virtual_alias_reject_code</a> 16098 (default: 550)</b></DT><DD> 16099 16100 <p> 16101 The SMTP server reply code when a recipient address matches 16102 $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, and $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> specifies a list 16103 of lookup tables that does not match the recipient address. 16104 </p> 16105 16106 <p> 16107 This feature is available in Postfix 2.0 and later. 16108 </p> 16109 16110 16111 </DD> 16112 16113 <DT><b><a name="unknown_virtual_mailbox_reject_code">unknown_virtual_mailbox_reject_code</a> 16114 (default: 550)</b></DT><DD> 16115 16116 <p> 16117 The SMTP server reply code when a recipient address matches 16118 $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>, and $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> specifies a list 16119 of lookup tables that does not match the recipient address. 16120 </p> 16121 16122 <p> 16123 This feature is available in Postfix 2.0 and later. 16124 </p> 16125 16126 16127 </DD> 16128 16129 <DT><b><a name="unverified_recipient_defer_code">unverified_recipient_defer_code</a> 16130 (default: 450)</b></DT><DD> 16131 16132 <p> 16133 The numerical Postfix SMTP server response when a recipient address 16134 probe fails due to a temporary error condition. 16135 </p> 16136 16137 <p> 16138 Unlike elsewhere in Postfix, you can specify 250 in order to 16139 accept the address anyway. 16140 </p> 16141 16142 <p> 16143 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 16144 </p> 16145 16146 <p> 16147 This feature is available in Postfix 2.6 and later. 16148 </p> 16149 16150 16151 </DD> 16152 16153 <DT><b><a name="unverified_recipient_reject_code">unverified_recipient_reject_code</a> 16154 (default: 450)</b></DT><DD> 16155 16156 <p> 16157 The numerical Postfix SMTP server response when a recipient address 16158 is rejected by the <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> restriction. 16159 </p> 16160 16161 <p> 16162 Unlike elsewhere in Postfix, you can specify 250 in order to 16163 accept the address anyway. 16164 </p> 16165 16166 <p> 16167 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 16168 </p> 16169 16170 <p> 16171 This feature is available in Postfix 2.1 and later. 16172 </p> 16173 16174 16175 </DD> 16176 16177 <DT><b><a name="unverified_recipient_reject_reason">unverified_recipient_reject_reason</a> 16178 (default: empty)</b></DT><DD> 16179 16180 <p> The Postfix SMTP server's reply when rejecting mail with 16181 <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>. Do not include the numeric SMTP reply 16182 code or the enhanced status code. By default, the response includes 16183 actual address verification details. 16184 16185 <p> Example: </p> 16186 16187 <pre> 16188 <a href="postconf.5.html#unverified_recipient_reject_reason">unverified_recipient_reject_reason</a> = Recipient address lookup failed 16189 </pre> 16190 16191 <p> This feature is available in Postfix 2.6 and later. </p> 16192 16193 16194 </DD> 16195 16196 <DT><b><a name="unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a> 16197 (default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD> 16198 16199 <p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> 16200 fails due to a temporary error condition. Specify "defer" to defer 16201 the remote SMTP client request immediately. With the default 16202 "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look 16203 for opportunities to reject mail, and defers the client request 16204 only if it would otherwise be accepted. </p> 16205 16206 <p> This feature is available in Postfix 2.6 and later. </p> 16207 16208 16209 </DD> 16210 16211 <DT><b><a name="unverified_sender_defer_code">unverified_sender_defer_code</a> 16212 (default: 450)</b></DT><DD> 16213 16214 <p> 16215 The numerical Postfix SMTP server response code when a sender address 16216 probe fails due to a temporary error condition. 16217 </p> 16218 16219 <p> 16220 Unlike elsewhere in Postfix, you can specify 250 in order to 16221 accept the address anyway. 16222 </p> 16223 16224 <p> 16225 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 16226 </p> 16227 16228 <p> 16229 This feature is available in Postfix 2.6 and later. 16230 </p> 16231 16232 16233 </DD> 16234 16235 <DT><b><a name="unverified_sender_reject_code">unverified_sender_reject_code</a> 16236 (default: 450)</b></DT><DD> 16237 16238 <p> 16239 The numerical Postfix SMTP server response code when a recipient 16240 address is rejected by the <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> restriction. 16241 </p> 16242 16243 <p> 16244 Unlike elsewhere in Postfix, you can specify 250 in order to 16245 accept the address anyway. 16246 </p> 16247 16248 <p> 16249 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 16250 </p> 16251 16252 <p> 16253 This feature is available in Postfix 2.1 and later. 16254 </p> 16255 16256 16257 </DD> 16258 16259 <DT><b><a name="unverified_sender_reject_reason">unverified_sender_reject_reason</a> 16260 (default: empty)</b></DT><DD> 16261 16262 <p> The Postfix SMTP server's reply when rejecting mail with 16263 <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a>. Do not include the numeric SMTP reply 16264 code or the enhanced status code. By default, the response includes 16265 actual address verification details. 16266 16267 <p> Example: </p> 16268 16269 <pre> 16270 <a href="postconf.5.html#unverified_sender_reject_reason">unverified_sender_reject_reason</a> = Sender address lookup failed 16271 </pre> 16272 16273 <p> This feature is available in Postfix 2.6 and later. </p> 16274 16275 16276 </DD> 16277 16278 <DT><b><a name="unverified_sender_tempfail_action">unverified_sender_tempfail_action</a> 16279 (default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD> 16280 16281 <p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> 16282 fails due to a temporary error condition. Specify "defer" to defer 16283 the remote SMTP client request immediately. With the default 16284 "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look 16285 for opportunities to reject mail, and defers the client request 16286 only if it would otherwise be accepted. </p> 16287 16288 <p> This feature is available in Postfix 2.6 and later. </p> 16289 16290 16291 </DD> 16292 16293 <DT><b><a name="verp_delimiter_filter">verp_delimiter_filter</a> 16294 (default: -=+)</b></DT><DD> 16295 16296 <p> 16297 The characters Postfix accepts as VERP delimiter characters on the 16298 Postfix <a href="sendmail.1.html">sendmail(1)</a> command line and in SMTP commands. 16299 </p> 16300 16301 <p> 16302 This feature is available in Postfix 1.1 and later. 16303 </p> 16304 16305 16306 </DD> 16307 16308 <DT><b><a name="virtual_alias_domains">virtual_alias_domains</a> 16309 (default: $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>)</b></DT><DD> 16310 16311 <p> Postfix is final destination for the specified list of virtual 16312 alias domains, that is, domains for which all addresses are aliased 16313 to addresses in other local or remote domains. The SMTP server 16314 validates recipient addresses with $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> and rejects 16315 non-existent recipients. See also the <a href="ADDRESS_CLASS_README.html#virtual_alias_class">virtual alias domain</a> class 16316 in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file </p> 16317 16318 <p> 16319 This feature is available in Postfix 2.0 and later. The default 16320 value is backwards compatible with Postfix version 1.1. 16321 </p> 16322 16323 <p> 16324 The default value is $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> so that you can keep all 16325 information about <a href="ADDRESS_CLASS_README.html#virtual_alias_class">virtual alias domains</a> in one place. If you have 16326 many users, it is better to separate information that changes more 16327 frequently (virtual address -> local or remote address mapping) 16328 from information that changes less frequently (the list of virtual 16329 domain names). 16330 </p> 16331 16332 <p> Specify a list of host or domain names, "/file/name" or 16333 "<a href="DATABASE_README.html">type:table</a>" patterns, separated by commas and/or whitespace. A 16334 "/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" 16335 lookup table is matched when a table entry matches a lookup string 16336 (the lookup result is ignored). Continue long lines by starting 16337 the next line with whitespace. Specify "!pattern" to exclude a host 16338 or domain name from the list. The form "!/file/name" is supported 16339 only in Postfix version 2.4 and later. </p> 16340 16341 <p> 16342 See also the <a href="VIRTUAL_README.html">VIRTUAL_README</a> and <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> documents 16343 for further information. 16344 </p> 16345 16346 <p> 16347 Example: 16348 </p> 16349 16350 <pre> 16351 <a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> = virtual1.tld virtual2.tld 16352 </pre> 16353 16354 16355 </DD> 16356 16357 <DT><b><a name="virtual_alias_expansion_limit">virtual_alias_expansion_limit</a> 16358 (default: 1000)</b></DT><DD> 16359 16360 <p> 16361 The maximal number of addresses that virtual alias expansion produces 16362 from each original recipient. 16363 </p> 16364 16365 <p> 16366 This feature is available in Postfix 2.1 and later. 16367 </p> 16368 16369 16370 </DD> 16371 16372 <DT><b><a name="virtual_alias_maps">virtual_alias_maps</a> 16373 (default: $<a href="postconf.5.html#virtual_maps">virtual_maps</a>)</b></DT><DD> 16374 16375 <p> 16376 Optional lookup tables that alias specific mail addresses or domains 16377 to other local or remote address. The table format and lookups 16378 are documented in <a href="virtual.5.html">virtual(5)</a>. For an overview of Postfix address 16379 manipulations see the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> document. 16380 </p> 16381 16382 <p> 16383 This feature is available in Postfix 2.0 and later. The default 16384 value is backwards compatible with Postfix version 1.1. 16385 </p> 16386 16387 <p> 16388 If you use this feature with indexed files, run "<b>postmap 16389 /etc/postfix/virtual</b>" after changing the file. 16390 </p> 16391 16392 <p> 16393 Examples: 16394 </p> 16395 16396 <pre> 16397 <a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> = dbm:/etc/postfix/virtual 16398 <a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> = hash:/etc/postfix/virtual 16399 </pre> 16400 16401 16402 </DD> 16403 16404 <DT><b><a name="virtual_alias_recursion_limit">virtual_alias_recursion_limit</a> 16405 (default: 1000)</b></DT><DD> 16406 16407 <p> 16408 The maximal nesting depth of virtual alias expansion. Currently 16409 the recursion limit is applied only to the left branch of the 16410 expansion graph, so the depth of the tree can in the worst case 16411 reach the sum of the expansion and recursion limits. This may 16412 change in the future. 16413 </p> 16414 16415 <p> 16416 This feature is available in Postfix 2.1 and later. 16417 </p> 16418 16419 16420 </DD> 16421 16422 <DT><b><a name="virtual_destination_concurrency_limit">virtual_destination_concurrency_limit</a> 16423 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 16424 16425 <p> The maximal number of parallel deliveries to the same destination 16426 via the virtual message delivery transport. This limit is enforced 16427 by the queue manager. The message delivery transport name is the 16428 first field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 16429 16430 16431 </DD> 16432 16433 <DT><b><a name="virtual_destination_recipient_limit">virtual_destination_recipient_limit</a> 16434 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 16435 16436 <p> The maximal number of recipients per message for the virtual 16437 message delivery transport. This limit is enforced by the queue 16438 manager. The message delivery transport name is the first field in 16439 the entry in the <a href="master.5.html">master.cf</a> file. </p> 16440 16441 <p> Setting this parameter to a value of 1 changes the meaning of 16442 <a href="postconf.5.html#virtual_destination_concurrency_limit">virtual_destination_concurrency_limit</a> from concurrency per domain 16443 into concurrency per recipient. </p> 16444 16445 16446 </DD> 16447 16448 <DT><b><a name="virtual_gid_maps">virtual_gid_maps</a> 16449 (default: empty)</b></DT><DD> 16450 16451 <p> 16452 Lookup tables with the per-recipient group ID for <a href="virtual.8.html">virtual(8)</a> mailbox 16453 delivery. 16454 </p> 16455 16456 <p> 16457 In a lookup table, specify a left-hand side of "@domain.tld" to 16458 match any user in the specified domain that does not have a specific 16459 "user (a] domain.tld" entry. 16460 </p> 16461 16462 <p> 16463 When a recipient address has an optional address extension 16464 (user+foo (a] domain.tld), the <a href="virtual.8.html">virtual(8)</a> delivery agent looks up 16465 the full address first, and when the lookup fails, it looks up the 16466 unextended address (user (a] domain.tld). 16467 </p> 16468 16469 <p> 16470 Note 1: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent disallows 16471 regular expression substitution of $1 etc. in regular expression 16472 lookup tables, because that would open a security hole. 16473 </p> 16474 16475 <p> 16476 Note 2: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent will 16477 silently ignore requests to use the <a href="proxymap.8.html">proxymap(8)</a> server. Instead 16478 it will open the table directly. Before Postfix version 2.2, the 16479 <a href="virtual.8.html">virtual(8)</a> delivery agent will terminate with a fatal error. 16480 </p> 16481 16482 16483 </DD> 16484 16485 <DT><b><a name="virtual_mailbox_base">virtual_mailbox_base</a> 16486 (default: empty)</b></DT><DD> 16487 16488 <p> 16489 A prefix that the <a href="virtual.8.html">virtual(8)</a> delivery agent prepends to all pathname 16490 results from $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> table lookups. This is a safety 16491 measure to ensure that an out of control map doesn't litter the 16492 file system with mailboxes. While <a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> could be 16493 set to "/", this setting isn't recommended. 16494 </p> 16495 16496 <p> 16497 Example: 16498 </p> 16499 16500 <pre> 16501 <a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> = /var/mail 16502 </pre> 16503 16504 16505 </DD> 16506 16507 <DT><b><a name="virtual_mailbox_domains">virtual_mailbox_domains</a> 16508 (default: $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>)</b></DT><DD> 16509 16510 <p> Postfix is final destination for the specified list of domains; 16511 mail is delivered via the $<a href="postconf.5.html#virtual_transport">virtual_transport</a> mail delivery transport. 16512 By default this is the Postfix <a href="virtual.8.html">virtual(8)</a> delivery agent. The SMTP 16513 server validates recipient addresses with $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> 16514 and rejects mail for non-existent recipients. See also the virtual 16515 mailbox domain class in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file. </p> 16516 16517 <p> This parameter expects the same syntax as the <a href="postconf.5.html#mydestination">mydestination</a> 16518 configuration parameter. </p> 16519 16520 <p> 16521 This feature is available in Postfix 2.0 and later. The default 16522 value is backwards compatible with Postfix version 1.1. 16523 </p> 16524 16525 16526 </DD> 16527 16528 <DT><b><a name="virtual_mailbox_limit">virtual_mailbox_limit</a> 16529 (default: 51200000)</b></DT><DD> 16530 16531 <p> 16532 The maximal size in bytes of an individual <a href="virtual.8.html">virtual(8)</a> mailbox or 16533 maildir file, or zero (no limit). </p> 16534 16535 16536 </DD> 16537 16538 <DT><b><a name="virtual_mailbox_lock">virtual_mailbox_lock</a> 16539 (default: see "postconf -d" output)</b></DT><DD> 16540 16541 <p> 16542 How to lock a UNIX-style <a href="virtual.8.html">virtual(8)</a> mailbox before attempting 16543 delivery. For a list of available file locking methods, use the 16544 "<b>postconf -l</b>" command. 16545 </p> 16546 16547 <p> 16548 This setting is ignored with <b>maildir</b> style delivery, because 16549 such deliveries are safe without application-level locks. 16550 </p> 16551 16552 <p> 16553 Note 1: the <b>dotlock</b> method requires that the recipient UID 16554 or GID has write access to the parent directory of the recipient's 16555 mailbox file. 16556 </p> 16557 16558 <p> 16559 Note 2: the default setting of this parameter is system dependent. 16560 </p> 16561 16562 16563 </DD> 16564 16565 <DT><b><a name="virtual_mailbox_maps">virtual_mailbox_maps</a> 16566 (default: empty)</b></DT><DD> 16567 16568 <p> 16569 Optional lookup tables with all valid addresses in the domains that 16570 match $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. 16571 </p> 16572 16573 <p> 16574 In a lookup table, specify a left-hand side of "@domain.tld" to 16575 match any user in the specified domain that does not have a specific 16576 "user (a] domain.tld" entry. 16577 </p> 16578 16579 <p> 16580 The <a href="virtual.8.html">virtual(8)</a> delivery agent uses this table to look up the 16581 per-recipient mailbox or maildir pathname. If the lookup result 16582 ends in a slash ("/"), maildir-style delivery is carried out, 16583 otherwise the path is assumed to specify a UNIX-style mailbox file. 16584 Note that $<a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> is unconditionally prepended to 16585 this path. 16586 </p> 16587 16588 <p> 16589 When a recipient address has an optional address extension 16590 (user+foo (a] domain.tld), the <a href="virtual.8.html">virtual(8)</a> delivery agent looks up 16591 the full address first, and when the lookup fails, it looks up the 16592 unextended address (user (a] domain.tld). 16593 </p> 16594 16595 <p> 16596 Note 1: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent disallows 16597 regular expression substitution of $1 etc. in regular expression 16598 lookup tables, because that would open a security hole. 16599 </p> 16600 16601 <p> 16602 Note 2: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent will 16603 silently ignore requests to use the <a href="proxymap.8.html">proxymap(8)</a> server. Instead 16604 it will open the table directly. Before Postfix version 2.2, the 16605 <a href="virtual.8.html">virtual(8)</a> delivery agent will terminate with a fatal error. 16606 </p> 16607 16608 16609 </DD> 16610 16611 <DT><b><a name="virtual_maps">virtual_maps</a> 16612 (default: empty)</b></DT><DD> 16613 16614 <p> Optional lookup tables with a) names of domains for which all 16615 addresses are aliased to addresses in other local or remote domains, 16616 and b) addresses that are aliased to addresses in other local or 16617 remote domains. Available before Postfix version 2.0. With Postfix 16618 version 2.0 and later, this is replaced by separate controls: <a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> 16619 and <a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>. </p> 16620 16621 16622 </DD> 16623 16624 <DT><b><a name="virtual_minimum_uid">virtual_minimum_uid</a> 16625 (default: 100)</b></DT><DD> 16626 16627 <p> 16628 The minimum user ID value that the <a href="virtual.8.html">virtual(8)</a> delivery agent accepts 16629 as a result from $<a href="postconf.5.html#virtual_uid_maps">virtual_uid_maps</a> table lookup. Returned 16630 values less than this will be rejected, and the message will be 16631 deferred. 16632 </p> 16633 16634 16635 </DD> 16636 16637 <DT><b><a name="virtual_transport">virtual_transport</a> 16638 (default: virtual)</b></DT><DD> 16639 16640 <p> 16641 The default mail delivery transport and next-hop destination for 16642 final delivery to domains listed with $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. 16643 This information can be overruled with the <a href="transport.5.html">transport(5)</a> table. 16644 </p> 16645 16646 <p> 16647 Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i> 16648 is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>. 16649 The <i>:nexthop</i> destination is optional; its syntax is documented 16650 in the manual page of the corresponding delivery agent. 16651 </p> 16652 16653 <p> 16654 This feature is available in Postfix 2.0 and later. 16655 </p> 16656 16657 16658 </DD> 16659 16660 <DT><b><a name="virtual_uid_maps">virtual_uid_maps</a> 16661 (default: empty)</b></DT><DD> 16662 16663 <p> 16664 Lookup tables with the per-recipient user ID that the <a href="virtual.8.html">virtual(8)</a> 16665 delivery agent uses while writing to the recipient's mailbox. 16666 </p> 16667 16668 <p> 16669 In a lookup table, specify a left-hand side of "@domain.tld" 16670 to match any user in the specified domain that does not have a 16671 specific "user (a] domain.tld" entry. 16672 </p> 16673 16674 <p> 16675 When a recipient address has an optional address extension 16676 (user+foo (a] domain.tld), the <a href="virtual.8.html">virtual(8)</a> delivery agent looks up 16677 the full address first, and when the lookup fails, it looks up the 16678 unextended address (user (a] domain.tld). 16679 </p> 16680 16681 <p> 16682 Note 1: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent disallows 16683 regular expression substitution of $1 etc. in regular expression 16684 lookup tables, because that would open a security hole. 16685 </p> 16686 16687 <p> 16688 Note 2: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent will 16689 silently ignore requests to use the <a href="proxymap.8.html">proxymap(8)</a> server. Instead 16690 it will open the table directly. Before Postfix version 2.2, the 16691 <a href="virtual.8.html">virtual(8)</a> delivery agent will terminate with a fatal error. 16692 </p> 16693 16694 16695 </DD> 16696 16697 </dl> 16698 16699 </body> 16700 16701 </html> 16702
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