postconf.5.html revision 1.1.1.3
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_default_transport">address_verify_default_transport</a> 125 (default: $<a href="postconf.5.html#default_transport">default_transport</a>)</b></DT><DD> 126 127 <p> 128 Overrides the <a href="postconf.5.html#default_transport">default_transport</a> parameter setting for address 129 verification probes. 130 </p> 131 132 <p> 133 This feature is available in Postfix 2.1 and later. 134 </p> 135 136 137 </DD> 138 139 <DT><b><a name="address_verify_local_transport">address_verify_local_transport</a> 140 (default: $<a href="postconf.5.html#local_transport">local_transport</a>)</b></DT><DD> 141 142 <p> 143 Overrides the <a href="postconf.5.html#local_transport">local_transport</a> parameter setting for address 144 verification probes. 145 </p> 146 147 <p> 148 This feature is available in Postfix 2.1 and later. 149 </p> 150 151 152 </DD> 153 154 <DT><b><a name="address_verify_map">address_verify_map</a> 155 (default: empty)</b></DT><DD> 156 157 <p> 158 Optional lookup table for persistent address verification status 159 storage. The table is maintained by the <a href="verify.8.html">verify(8)</a> service, and 160 is opened before the process releases privileges. 161 </p> 162 163 <p> 164 By default, the information is kept in volatile memory, and is lost 165 after "<b>postfix reload</b>" or "<b>postfix stop</b>". 166 </p> 167 168 <p> 169 Specify a location in a file system that will not fill up. If the 170 database becomes corrupted, the world comes to an end. To recover 171 delete the file and do "<b>postfix reload</b>". 172 </p> 173 174 <p> As of version 2.5, Postfix no longer uses root privileges when 175 opening this file. The file should now be stored under the Postfix-owned 176 <a href="postconf.5.html#data_directory">data_directory</a>. As a migration aid, an attempt to open the file 177 under a non-Postfix directory is redirected to the Postfix-owned 178 <a href="postconf.5.html#data_directory">data_directory</a>, and a warning is logged. </p> 179 180 <p> 181 Examples: 182 </p> 183 184 <pre> 185 <a href="postconf.5.html#address_verify_map">address_verify_map</a> = hash:/var/lib/postfix/verify 186 <a href="postconf.5.html#address_verify_map">address_verify_map</a> = btree:/var/lib/postfix/verify 187 </pre> 188 189 <p> 190 This feature is available in Postfix 2.1 and later. 191 </p> 192 193 194 </DD> 195 196 <DT><b><a name="address_verify_negative_cache">address_verify_negative_cache</a> 197 (default: yes)</b></DT><DD> 198 199 <p> 200 Enable caching of failed address verification probe results. When 201 this feature is enabled, the cache may pollute quickly with garbage. 202 When this feature is disabled, Postfix will generate an address 203 probe for every lookup. 204 </p> 205 206 <p> 207 This feature is available in Postfix 2.1 and later. 208 </p> 209 210 211 </DD> 212 213 <DT><b><a name="address_verify_negative_expire_time">address_verify_negative_expire_time</a> 214 (default: 3d)</b></DT><DD> 215 216 <p> 217 The time after which a failed probe expires from the address 218 verification cache. 219 </p> 220 221 <p> 222 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 223 </p> 224 225 <p> 226 This feature is available in Postfix 2.1 and later. 227 </p> 228 229 230 </DD> 231 232 <DT><b><a name="address_verify_negative_refresh_time">address_verify_negative_refresh_time</a> 233 (default: 3h)</b></DT><DD> 234 235 <p> 236 The time after which a failed address verification probe needs to 237 be refreshed. 238 </p> 239 240 <p> 241 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 242 </p> 243 244 <p> 245 This feature is available in Postfix 2.1 and later. 246 </p> 247 248 249 </DD> 250 251 <DT><b><a name="address_verify_poll_count">address_verify_poll_count</a> 252 (default: 3)</b></DT><DD> 253 254 <p> 255 How many times to query the <a href="verify.8.html">verify(8)</a> service for the completion 256 of an address verification request in progress. 257 </p> 258 259 <p> By default, the Postfix SMTP server polls the <a href="verify.8.html">verify(8)</a> service 260 up to three times under non-overload conditions, and only once when 261 under overload. With Postfix version 2.5 and earlier, the SMTP 262 server always polls the <a href="verify.8.html">verify(8)</a> service up to three times by 263 default. </p> 264 265 <p> 266 Specify 1 to implement a crude form of greylisting, that is, always 267 defer the first delivery request for a never seen before address. 268 </p> 269 270 <p> 271 Example: 272 </p> 273 274 <pre> 275 <a href="postconf.5.html#address_verify_poll_count">address_verify_poll_count</a> = 1 276 </pre> 277 278 <p> 279 This feature is available in Postfix 2.1 and later. 280 </p> 281 282 283 </DD> 284 285 <DT><b><a name="address_verify_poll_delay">address_verify_poll_delay</a> 286 (default: 3s)</b></DT><DD> 287 288 <p> 289 The delay between queries for the completion of an address 290 verification request in progress. 291 </p> 292 293 <p> 294 The default polling delay is 3 seconds. 295 </p> 296 297 <p> 298 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 299 </p> 300 301 <p> 302 This feature is available in Postfix 2.1 and later. 303 </p> 304 305 306 </DD> 307 308 <DT><b><a name="address_verify_positive_expire_time">address_verify_positive_expire_time</a> 309 (default: 31d)</b></DT><DD> 310 311 <p> 312 The time after which a successful probe expires from the address 313 verification cache. 314 </p> 315 316 <p> 317 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 318 </p> 319 320 <p> 321 This feature is available in Postfix 2.1 and later. 322 </p> 323 324 325 </DD> 326 327 <DT><b><a name="address_verify_positive_refresh_time">address_verify_positive_refresh_time</a> 328 (default: 7d)</b></DT><DD> 329 330 <p> 331 The time after which a successful address verification probe needs 332 to be refreshed. The address verification status is not updated 333 when the probe fails (optimistic caching). 334 </p> 335 336 <p> 337 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 338 </p> 339 340 <p> 341 This feature is available in Postfix 2.1 and later. 342 </p> 343 344 345 </DD> 346 347 <DT><b><a name="address_verify_relay_transport">address_verify_relay_transport</a> 348 (default: $<a href="postconf.5.html#relay_transport">relay_transport</a>)</b></DT><DD> 349 350 <p> 351 Overrides the <a href="postconf.5.html#relay_transport">relay_transport</a> parameter setting for address 352 verification probes. 353 </p> 354 355 <p> 356 This feature is available in Postfix 2.1 and later. 357 </p> 358 359 360 </DD> 361 362 <DT><b><a name="address_verify_relayhost">address_verify_relayhost</a> 363 (default: $<a href="postconf.5.html#relayhost">relayhost</a>)</b></DT><DD> 364 365 <p> 366 Overrides the <a href="postconf.5.html#relayhost">relayhost</a> parameter setting for address verification 367 probes. This information can be overruled with the <a href="transport.5.html">transport(5)</a> table. 368 </p> 369 370 <p> 371 This feature is available in Postfix 2.1 and later. 372 </p> 373 374 375 </DD> 376 377 <DT><b><a name="address_verify_sender">address_verify_sender</a> 378 (default: $<a href="postconf.5.html#double_bounce_sender">double_bounce_sender</a>)</b></DT><DD> 379 380 <p> The sender address to use in address verification probes; prior 381 to Postfix 2.5 the default was "postmaster". To 382 avoid problems with address probes that are sent in response to 383 address probes, the Postfix SMTP server excludes the probe sender 384 address from all SMTPD access blocks. </p> 385 386 <p> 387 Specify an empty value (<a href="postconf.5.html#address_verify_sender">address_verify_sender</a> =) or <> if you want 388 to use the null sender address. Beware, some sites reject mail from 389 <>, even though RFCs require that such addresses be accepted. 390 </p> 391 392 <p> 393 Examples: 394 </p> 395 396 <pre> 397 <a href="postconf.5.html#address_verify_sender">address_verify_sender</a> = <> 398 <a href="postconf.5.html#address_verify_sender">address_verify_sender</a> = postmaster (a] my.domain 399 </pre> 400 401 <p> 402 This feature is available in Postfix 2.1 and later. 403 </p> 404 405 406 </DD> 407 408 <DT><b><a name="address_verify_sender_dependent_relayhost_maps">address_verify_sender_dependent_relayhost_maps</a> 409 (default: $<a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>)</b></DT><DD> 410 411 <p> 412 Overrides the <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> parameter setting for address 413 verification probes. 414 </p> 415 416 <p> 417 This feature is available in Postfix 2.3 and later. 418 </p> 419 420 421 </DD> 422 423 <DT><b><a name="address_verify_service_name">address_verify_service_name</a> 424 (default: verify)</b></DT><DD> 425 426 <p> 427 The name of the <a href="verify.8.html">verify(8)</a> address verification service. This service 428 maintains the status of sender and/or recipient address verification 429 probes, and generates probes on request by other Postfix processes. 430 </p> 431 432 433 </DD> 434 435 <DT><b><a name="address_verify_transport_maps">address_verify_transport_maps</a> 436 (default: $<a href="postconf.5.html#transport_maps">transport_maps</a>)</b></DT><DD> 437 438 <p> 439 Overrides the <a href="postconf.5.html#transport_maps">transport_maps</a> parameter setting for address verification 440 probes. 441 </p> 442 443 <p> 444 This feature is available in Postfix 2.1 and later. 445 </p> 446 447 448 </DD> 449 450 <DT><b><a name="address_verify_virtual_transport">address_verify_virtual_transport</a> 451 (default: $<a href="postconf.5.html#virtual_transport">virtual_transport</a>)</b></DT><DD> 452 453 <p> 454 Overrides the <a href="postconf.5.html#virtual_transport">virtual_transport</a> parameter setting for address 455 verification probes. 456 </p> 457 458 <p> 459 This feature is available in Postfix 2.1 and later. 460 </p> 461 462 463 </DD> 464 465 <DT><b><a name="alias_database">alias_database</a> 466 (default: see "postconf -d" output)</b></DT><DD> 467 468 <p> 469 The alias databases for <a href="local.8.html">local(8)</a> delivery that are updated with 470 "<b>newaliases</b>" or with "<b>sendmail -bi</b>". 471 </p> 472 473 <p> 474 This is a separate configuration parameter because not all the 475 tables specified with $<a href="postconf.5.html#alias_maps">alias_maps</a> have to be local files. 476 </p> 477 478 <p> 479 Examples: 480 </p> 481 482 <pre> 483 <a href="postconf.5.html#alias_database">alias_database</a> = hash:/etc/aliases 484 <a href="postconf.5.html#alias_database">alias_database</a> = hash:/etc/mail/aliases 485 </pre> 486 487 488 </DD> 489 490 <DT><b><a name="alias_maps">alias_maps</a> 491 (default: see "postconf -d" output)</b></DT><DD> 492 493 <p> 494 The alias databases that are used for <a href="local.8.html">local(8)</a> delivery. See 495 <a href="aliases.5.html">aliases(5)</a> for syntax details. 496 </p> 497 498 <p> 499 The default list is system dependent. On systems with NIS, the 500 default is to search the local alias database, then the NIS alias 501 database. 502 </p> 503 504 <p> 505 If you change the alias database, run "<b>postalias /etc/aliases</b>" 506 (or wherever your system stores the mail alias file), or simply 507 run "<b>newaliases</b>" to build the necessary DBM or DB file. 508 </p> 509 510 <p> 511 The <a href="local.8.html">local(8)</a> delivery agent disallows regular expression substitution 512 of $1 etc. in <a href="postconf.5.html#alias_maps">alias_maps</a>, because that would open a security hole. 513 </p> 514 515 <p> 516 The <a href="local.8.html">local(8)</a> delivery agent will silently ignore requests to use 517 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 518 table directly. Before Postfix version 2.2, the <a href="local.8.html">local(8)</a> delivery 519 agent will terminate with a fatal error. 520 </p> 521 522 <p> 523 Examples: 524 </p> 525 526 <pre> 527 <a href="postconf.5.html#alias_maps">alias_maps</a> = hash:/etc/aliases, nis:mail.aliases 528 <a href="postconf.5.html#alias_maps">alias_maps</a> = hash:/etc/aliases 529 </pre> 530 531 532 </DD> 533 534 <DT><b><a name="allow_mail_to_commands">allow_mail_to_commands</a> 535 (default: alias, forward)</b></DT><DD> 536 537 <p> 538 Restrict <a href="local.8.html">local(8)</a> mail delivery to external commands. The default 539 is to disallow delivery to "|command" in :include: files (see 540 <a href="aliases.5.html">aliases(5)</a> for the text that defines this terminology). 541 </p> 542 543 <p> 544 Specify zero or more of: <b>alias</b>, <b>forward</b> or <b>include</b>, 545 in order to allow commands in <a href="aliases.5.html">aliases(5)</a>, .forward files or in 546 :include: files, respectively. 547 </p> 548 549 <p> 550 Example: 551 </p> 552 553 <pre> 554 <a href="postconf.5.html#allow_mail_to_commands">allow_mail_to_commands</a> = alias,forward,include 555 </pre> 556 557 558 </DD> 559 560 <DT><b><a name="allow_mail_to_files">allow_mail_to_files</a> 561 (default: alias, forward)</b></DT><DD> 562 563 <p> 564 Restrict <a href="local.8.html">local(8)</a> mail delivery to external files. The default is 565 to disallow "/file/name" destinations in :include: files (see 566 <a href="aliases.5.html">aliases(5)</a> for the text that defines this terminology). 567 </p> 568 569 <p> 570 Specify zero or more of: <b>alias</b>, <b>forward</b> or <b>include</b>, 571 in order to allow "/file/name" destinations in <a href="aliases.5.html">aliases(5)</a>, .forward 572 files and in :include: files, respectively. 573 </p> 574 575 <p> 576 Example: 577 </p> 578 579 <pre> 580 <a href="postconf.5.html#allow_mail_to_files">allow_mail_to_files</a> = alias,forward,include 581 </pre> 582 583 584 </DD> 585 586 <DT><b><a name="allow_min_user">allow_min_user</a> 587 (default: no)</b></DT><DD> 588 589 <p> 590 Allow a sender or recipient address to have `-' as the first 591 character. By 592 default, this is not allowed, to avoid accidents with software that 593 passes email addresses via the command line. Such software 594 would not be able to distinguish a malicious address from a 595 bona fide command-line option. Although this can be prevented by 596 inserting a "--" option terminator into the command line, this is 597 difficult to enforce consistently and globally. </p> 598 599 <p> As of Postfix version 2.5, this feature is implemented by 600 <a href="trivial-rewrite.8.html">trivial-rewrite(8)</a>. With earlier versions this feature was implemented 601 by <a href="qmgr.8.html">qmgr(8)</a> and was limited to recipient addresses only. </p> 602 603 604 </DD> 605 606 <DT><b><a name="allow_percent_hack">allow_percent_hack</a> 607 (default: yes)</b></DT><DD> 608 609 <p> 610 Enable the rewriting of the form "user%domain" to "user@domain". 611 This is enabled by default. 612 </p> 613 614 <p> Note: with Postfix version 2.2, message header address rewriting 615 happens only when one of the following conditions is true: </p> 616 617 <ul> 618 619 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 620 621 <li> The message is received from a network client that matches 622 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 623 624 <li> The message is received from the network, and the 625 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 626 627 </ul> 628 629 <p> To get the behavior before Postfix version 2.2, specify 630 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 631 632 <p> 633 Example: 634 </p> 635 636 <pre> 637 <a href="postconf.5.html#allow_percent_hack">allow_percent_hack</a> = no 638 </pre> 639 640 641 </DD> 642 643 <DT><b><a name="allow_untrusted_routing">allow_untrusted_routing</a> 644 (default: no)</b></DT><DD> 645 646 <p> 647 Forward mail with sender-specified routing (user[@%!]remote[@%!]site) 648 from untrusted clients to destinations matching $<a href="postconf.5.html#relay_domains">relay_domains</a>. 649 </p> 650 651 <p> 652 By default, this feature is turned off. This closes a nasty open 653 relay loophole where a backup MX host can be tricked into forwarding 654 junk mail to a primary MX host which then spams it out to the world. 655 </p> 656 657 <p> 658 This parameter also controls if non-local addresses with sender-specified 659 routing can match Postfix access tables. By default, such addresses 660 cannot match Postfix access tables, because the address is ambiguous. 661 </p> 662 663 664 </DD> 665 666 <DT><b><a name="alternate_config_directories">alternate_config_directories</a> 667 (default: empty)</b></DT><DD> 668 669 <p> 670 A list of non-default Postfix configuration directories that may 671 be specified with "-c <a href="postconf.5.html#config_directory">config_directory</a>" on the command line, or 672 via the MAIL_CONFIG environment parameter. 673 </p> 674 675 <p> 676 This list must be specified in the default Postfix configuration 677 directory, and is used by set-gid Postfix commands such as <a href="postqueue.1.html">postqueue(1)</a> 678 and <a href="postdrop.1.html">postdrop(1)</a>. 679 </p> 680 681 682 </DD> 683 684 <DT><b><a name="always_add_missing_headers">always_add_missing_headers</a> 685 (default: no)</b></DT><DD> 686 687 <p> Always add (Resent-) From:, To:, Date: or Message-ID: headers 688 when not present. Postfix 2.6 and later add these headers only 689 when clients match the <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> parameter 690 setting. Earlier Postfix versions always add these headers; this 691 may break DKIM signatures that cover non-existent headers. </p> 692 693 694 </DD> 695 696 <DT><b><a name="always_bcc">always_bcc</a> 697 (default: empty)</b></DT><DD> 698 699 <p> 700 Optional address that receives a "blind carbon copy" of each message 701 that is received by the Postfix mail system. 702 </p> 703 704 <p> 705 Note: if mail to the BCC address bounces it will be returned to 706 the sender. 707 </p> 708 709 <p> Note: automatic BCC recipients are produced only for new mail. 710 To avoid mailer loops, automatic BCC recipients are not generated 711 for mail that Postfix forwards internally, nor for mail that Postfix 712 generates itself. </p> 713 714 715 </DD> 716 717 <DT><b><a name="anvil_rate_time_unit">anvil_rate_time_unit</a> 718 (default: 60s)</b></DT><DD> 719 720 <p> 721 The time unit over which client connection rates and other rates 722 are calculated. 723 </p> 724 725 <p> 726 This feature is implemented by the <a href="anvil.8.html">anvil(8)</a> service which is available 727 in Postfix version 2.2 and later. 728 </p> 729 730 <p> 731 The default interval is relatively short. Because of the high 732 frequency of updates, the <a href="anvil.8.html">anvil(8)</a> server uses volatile memory 733 only. Thus, information is lost whenever the process terminates. 734 </p> 735 736 <p> 737 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 738 The default time unit is s (seconds). 739 </p> 740 741 742 </DD> 743 744 <DT><b><a name="anvil_status_update_time">anvil_status_update_time</a> 745 (default: 600s)</b></DT><DD> 746 747 <p> 748 How frequently the <a href="anvil.8.html">anvil(8)</a> connection and rate limiting server 749 logs peak usage information. 750 </p> 751 752 <p> 753 This feature is available in Postfix 2.2 and later. 754 </p> 755 756 <p> 757 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 758 The default time unit is s (seconds). 759 </p> 760 761 762 </DD> 763 764 <DT><b><a name="append_at_myorigin">append_at_myorigin</a> 765 (default: yes)</b></DT><DD> 766 767 <p> 768 With locally submitted mail, append the string "@$<a href="postconf.5.html#myorigin">myorigin</a>" to mail 769 addresses without domain information. With remotely submitted mail, 770 append the string "@$<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a>" instead. 771 </p> 772 773 <p> 774 Note 1: this feature is enabled by default and must not be turned off. 775 Postfix does not support domain-less addresses. 776 </p> 777 778 <p> Note 2: with Postfix version 2.2, message header address rewriting 779 happens only when one of the following conditions is true: </p> 780 781 <ul> 782 783 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 784 785 <li> The message is received from a network client that matches 786 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 787 788 <li> The message is received from the network, and the 789 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 790 791 </ul> 792 793 <p> To get the behavior before Postfix version 2.2, specify 794 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 795 796 797 </DD> 798 799 <DT><b><a name="append_dot_mydomain">append_dot_mydomain</a> 800 (default: yes)</b></DT><DD> 801 802 <p> 803 With locally submitted mail, append the string ".$<a href="postconf.5.html#mydomain">mydomain</a>" to 804 addresses that have no ".domain" information. With remotely submitted 805 mail, append the string ".$<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a>" 806 instead. 807 </p> 808 809 <p> 810 Note 1: this feature is enabled by default. If disabled, users will not be 811 able to send mail to "user@partialdomainname" but will have to 812 specify full domain names instead. 813 </p> 814 815 <p> Note 2: with Postfix version 2.2, message header address rewriting 816 happens only when one of the following conditions is true: </p> 817 818 <ul> 819 820 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 821 822 <li> The message is received from a network client that matches 823 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 824 825 <li> The message is received from the network, and the 826 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 827 828 </ul> 829 830 <p> To get the behavior before Postfix version 2.2, specify 831 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 832 833 834 </DD> 835 836 <DT><b><a name="application_event_drain_time">application_event_drain_time</a> 837 (default: 100s)</b></DT><DD> 838 839 <p> 840 How long the <a href="postkick.1.html">postkick(1)</a> command waits for a request to enter the 841 server's input buffer before giving up. 842 </p> 843 844 <p> 845 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 846 The default time unit is s (seconds). 847 </p> 848 849 <p> 850 This feature is available in Postfix 2.1 and later. 851 </p> 852 853 854 </DD> 855 856 <DT><b><a name="authorized_flush_users">authorized_flush_users</a> 857 (default: static:anyone)</b></DT><DD> 858 859 <p> 860 List of users who are authorized to flush the queue. 861 </p> 862 863 <p> 864 By default, all users are allowed to flush the queue. Access is 865 always granted if the invoking user is the super-user or the 866 $<a href="postconf.5.html#mail_owner">mail_owner</a> user. Otherwise, the real UID of the process is looked 867 up in the system password file, and access is granted only if the 868 corresponding login name is on the access list. The username 869 "unknown" is used for processes whose real UID is not found in the 870 password file. </p> 871 872 <p> 873 Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns, 874 separated by commas and/or whitespace. The list is matched left to 875 right, and the search stops on the first match. A "/file/name" 876 pattern is replaced 877 by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name 878 matches a lookup key (the lookup result is ignored). Continue long 879 lines by starting the next line with whitespace. Specify "!pattern" 880 to exclude a name from the list. The form "!/file/name" is supported 881 only in Postfix version 2.4 and later. </p> 882 883 <p> 884 This feature is available in Postfix 2.2 and later. 885 </p> 886 887 888 </DD> 889 890 <DT><b><a name="authorized_mailq_users">authorized_mailq_users</a> 891 (default: static:anyone)</b></DT><DD> 892 893 <p> 894 List of users who are authorized to view the queue. 895 </p> 896 897 <p> 898 By default, all users are allowed to view the queue. Access is 899 always granted if the invoking user is the super-user or the 900 $<a href="postconf.5.html#mail_owner">mail_owner</a> user. Otherwise, the real UID of the process is looked 901 up in the system password file, and access is granted only if the 902 corresponding login name is on the access list. The username 903 "unknown" is used for processes whose real UID is not found in the 904 password file. </p> 905 906 <p> 907 Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns, 908 separated by commas and/or whitespace. The list is matched left to 909 right, and the search stops on the first match. A "/file/name" 910 pattern is replaced 911 by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name 912 matches a lookup key (the lookup result is ignored). Continue long 913 lines by starting the next line with whitespace. Specify "!pattern" 914 to exclude a user name from the list. The form "!/file/name" is 915 supported only in Postfix version 2.4 and later. </p> 916 917 <p> 918 This feature is available in Postfix 2.2 and later. 919 </p> 920 921 922 </DD> 923 924 <DT><b><a name="authorized_submit_users">authorized_submit_users</a> 925 (default: static:anyone)</b></DT><DD> 926 927 <p> 928 List of users who are authorized to submit mail with the <a href="sendmail.1.html">sendmail(1)</a> 929 command (and with the privileged <a href="postdrop.1.html">postdrop(1)</a> helper command). 930 </p> 931 932 <p> 933 By default, all users are allowed to submit mail. Otherwise, the 934 real UID of the process is looked up in the system password file, 935 and access is granted only if the corresponding login name is on 936 the access list. The username "unknown" is used for processes 937 whose real UID is not found in the password file. To deny mail 938 submission access to all users specify an empty list. </p> 939 940 <p> 941 Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns, 942 separated by commas and/or whitespace. The list is matched left to right, 943 and the search stops on the first match. A "/file/name" pattern is 944 replaced by its contents; 945 a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name matches a lookup key 946 (the lookup result is ignored). Continue long lines by starting the 947 next line with whitespace. Specify "!pattern" to exclude a user 948 name from the list. The form "!/file/name" is supported only in 949 Postfix version 2.4 and later. </p> 950 951 <p> 952 Example: 953 </p> 954 955 <pre> 956 <a href="postconf.5.html#authorized_submit_users">authorized_submit_users</a> = !www, static:all 957 </pre> 958 959 <p> 960 This feature is available in Postfix 2.2 and later. 961 </p> 962 963 964 </DD> 965 966 <DT><b><a name="authorized_verp_clients">authorized_verp_clients</a> 967 (default: $<a href="postconf.5.html#mynetworks">mynetworks</a>)</b></DT><DD> 968 969 <p> What SMTP clients are allowed to specify the XVERP command. 970 This command requests that mail be delivered one recipient at a 971 time with a per recipient return address. </p> 972 973 <p> By default, only trusted clients are allowed to specify XVERP. 974 </p> 975 976 <p> This parameter was introduced with Postfix version 1.1. Postfix 977 version 2.1 renamed this parameter to <a href="postconf.5.html#smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a> 978 and changed the default to none. </p> 979 980 <p> Specify a list of network/netmask patterns, separated by commas 981 and/or whitespace. The mask specifies the number of bits in the 982 network part of a host address. You can also specify hostnames or 983 .domain names (the initial dot causes the domain to match any name 984 below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" 985 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 986 is matched when a table entry matches a lookup string (the lookup 987 result is ignored). Continue long lines by starting the next line 988 with whitespace. Specify "!pattern" to exclude an address or network 989 block from the list. The form "!/file/name" is supported only in 990 Postfix version 2.4 and later. </p> 991 992 <p> Note: IP version 6 address information must be specified inside 993 <tt>[]</tt> in the <a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a> value, and in files 994 specified with "/file/name". IP version 6 addresses contain the 995 ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 996 pattern. </p> 997 998 999 </DD> 1000 1001 <DT><b><a name="backwards_bounce_logfile_compatibility">backwards_bounce_logfile_compatibility</a> 1002 (default: yes)</b></DT><DD> 1003 1004 <p> 1005 Produce additional <a href="bounce.8.html">bounce(8)</a> logfile records that can be read by 1006 Postfix versions before 2.0. The current and more extensible "name = 1007 value" format is needed in order to implement more sophisticated 1008 functionality. 1009 </p> 1010 1011 <p> 1012 This feature is available in Postfix 2.1 and later. 1013 </p> 1014 1015 1016 </DD> 1017 1018 <DT><b><a name="berkeley_db_create_buffer_size">berkeley_db_create_buffer_size</a> 1019 (default: 16777216)</b></DT><DD> 1020 1021 <p> 1022 The per-table I/O buffer size for programs that create Berkeley DB 1023 hash or btree tables. Specify a byte count. 1024 </p> 1025 1026 <p> 1027 This feature is available in Postfix 2.0 and later. 1028 </p> 1029 1030 1031 </DD> 1032 1033 <DT><b><a name="berkeley_db_read_buffer_size">berkeley_db_read_buffer_size</a> 1034 (default: 131072)</b></DT><DD> 1035 1036 <p> 1037 The per-table I/O buffer size for programs that read Berkeley DB 1038 hash or btree tables. Specify a byte count. 1039 </p> 1040 1041 <p> 1042 This feature is available in Postfix 2.0 and later. 1043 </p> 1044 1045 1046 </DD> 1047 1048 <DT><b><a name="best_mx_transport">best_mx_transport</a> 1049 (default: empty)</b></DT><DD> 1050 1051 <p> 1052 Where the Postfix SMTP client should deliver mail when it detects 1053 a "mail loops back to myself" error condition. This happens when 1054 the local MTA is the best SMTP mail exchanger for a destination 1055 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>, 1056 $<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, 1057 the Postfix SMTP client returns such mail as undeliverable. 1058 </p> 1059 1060 <p> 1061 Specify, for example, "<a href="postconf.5.html#best_mx_transport">best_mx_transport</a> = local" to pass the mail 1062 from the Postfix SMTP client to the <a href="local.8.html">local(8)</a> delivery agent. You 1063 can specify 1064 any message delivery "transport" or "transport:nexthop" that is 1065 defined in the <a href="master.5.html">master.cf</a> file. See the <a href="transport.5.html">transport(5)</a> manual page 1066 for the syntax and meaning of "transport" or "transport:nexthop". 1067 </p> 1068 1069 <p> 1070 However, this feature is expensive because it ties up a Postfix 1071 SMTP client process while the <a href="local.8.html">local(8)</a> delivery agent is doing its 1072 work. It is more efficient (for Postfix) to list all <a href="VIRTUAL_README.html#canonical">hosted domains</a> 1073 in a table or database. 1074 </p> 1075 1076 1077 </DD> 1078 1079 <DT><b><a name="biff">biff</a> 1080 (default: yes)</b></DT><DD> 1081 1082 <p> 1083 Whether or not to use the local <a href="postconf.5.html#biff">biff</a> service. This service sends 1084 "new mail" notifications to users who have requested new mail 1085 notification with the UNIX command "<a href="postconf.5.html#biff">biff</a> y". 1086 </p> 1087 1088 <p> 1089 For compatibility reasons this feature is on by default. On systems 1090 with lots of interactive users, the <a href="postconf.5.html#biff">biff</a> service can be a performance 1091 drain. Specify "<a href="postconf.5.html#biff">biff</a> = no" in <a href="postconf.5.html">main.cf</a> to disable. 1092 </p> 1093 1094 1095 </DD> 1096 1097 <DT><b><a name="body_checks">body_checks</a> 1098 (default: empty)</b></DT><DD> 1099 1100 <p> Optional lookup tables for content inspection as specified in 1101 the <a href="header_checks.5.html">body_checks(5)</a> manual page. </p> 1102 1103 <p> Note: with Postfix versions before 2.0, these rules inspect 1104 all content after the primary message headers. </p> 1105 1106 1107 </DD> 1108 1109 <DT><b><a name="body_checks_size_limit">body_checks_size_limit</a> 1110 (default: 51200)</b></DT><DD> 1111 1112 <p> 1113 How much text in a message body segment (or attachment, if you 1114 prefer to use that term) is subjected to <a href="postconf.5.html#body_checks">body_checks</a> inspection. 1115 The amount of text is limited to avoid scanning huge attachments. 1116 </p> 1117 1118 <p> 1119 This feature is available in Postfix 2.0 and later. 1120 </p> 1121 1122 1123 </DD> 1124 1125 <DT><b><a name="bounce_notice_recipient">bounce_notice_recipient</a> 1126 (default: postmaster)</b></DT><DD> 1127 1128 <p> 1129 The recipient of postmaster notifications with the message headers 1130 of mail that Postfix did not deliver and of SMTP conversation 1131 transcripts of mail that Postfix did not receive. This feature is 1132 enabled with the <a href="postconf.5.html#notify_classes">notify_classes</a> parameter. </p> 1133 1134 1135 </DD> 1136 1137 <DT><b><a name="bounce_queue_lifetime">bounce_queue_lifetime</a> 1138 (default: 5d)</b></DT><DD> 1139 1140 <p> 1141 The maximal time a bounce message is queued before it is considered 1142 undeliverable. By default, this is the same as the queue life time 1143 for regular mail. 1144 </p> 1145 1146 <p> 1147 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 1148 The default time unit is d (days). 1149 </p> 1150 1151 <p> 1152 Specify 0 when mail delivery should be tried only once. 1153 </p> 1154 1155 <p> 1156 This feature is available in Postfix 2.1 and later. 1157 </p> 1158 1159 1160 </DD> 1161 1162 <DT><b><a name="bounce_service_name">bounce_service_name</a> 1163 (default: bounce)</b></DT><DD> 1164 1165 <p> 1166 The name of the <a href="bounce.8.html">bounce(8)</a> service. This service maintains a record 1167 of failed delivery attempts and generates non-delivery notifications. 1168 </p> 1169 1170 <p> 1171 This feature is available in Postfix 2.0 and later. 1172 </p> 1173 1174 1175 </DD> 1176 1177 <DT><b><a name="bounce_size_limit">bounce_size_limit</a> 1178 (default: 50000)</b></DT><DD> 1179 1180 <p> The maximal amount of original message text that is sent in a 1181 non-delivery notification. Specify a byte count. With Postfix 2.4 1182 and later, a message is returned as either message/rfc822 (the 1183 complete original) or as text/rfc822-headers (the headers only). 1184 With earlier Postfix versions, a message is always returned as 1185 message/rfc822 and is truncated when it exceeds the size limit. 1186 </p> 1187 1188 <p> Notes: </p> 1189 1190 <ul> 1191 1192 <li> <p> If you increase this limit, then you should increase the 1193 <a href="postconf.5.html#mime_nesting_limit">mime_nesting_limit</a> value proportionally. </p> 1194 1195 <li> <p> Be careful when making changes. Excessively large values 1196 will result in the loss of non-delivery notifications, when a bounce 1197 message size exceeds a local or remote MTA's message size limit. 1198 </p> 1199 1200 </ul> 1201 1202 1203 </DD> 1204 1205 <DT><b><a name="bounce_template_file">bounce_template_file</a> 1206 (default: empty)</b></DT><DD> 1207 1208 <p> Pathname of a configuration file with bounce message templates. 1209 These override the built-in templates of delivery status notification 1210 (DSN) messages for undeliverable mail, for delayed mail, successful 1211 delivery, or delivery verification. The <a href="bounce.5.html">bounce(5)</a> manual page 1212 describes how to edit and test template files. </p> 1213 1214 <p> Template message body text may contain $name references to 1215 Postfix configuration parameters. The result of $name expansion can 1216 be previewed with "<b>postconf -b <i>file_name</i></b>" before the file 1217 is placed into the Postfix configuration directory. </p> 1218 1219 <p> This feature is available in Postfix 2.3 and later. </p> 1220 1221 1222 </DD> 1223 1224 <DT><b><a name="broken_sasl_auth_clients">broken_sasl_auth_clients</a> 1225 (default: no)</b></DT><DD> 1226 1227 <p> 1228 Enable inter-operability with SMTP clients that implement an obsolete 1229 version of the AUTH command (<a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a>). Examples of such clients 1230 are MicroSoft Outlook Express version 4 and MicroSoft Exchange 1231 version 5.0. 1232 </p> 1233 1234 <p> 1235 Specify "<a href="postconf.5.html#broken_sasl_auth_clients">broken_sasl_auth_clients</a> = yes" to have Postfix advertise 1236 AUTH support in a non-standard way. 1237 </p> 1238 1239 1240 </DD> 1241 1242 <DT><b><a name="canonical_classes">canonical_classes</a> 1243 (default: envelope_sender, envelope_recipient, header_sender, header_recipient)</b></DT><DD> 1244 1245 <p> What addresses are subject to <a href="postconf.5.html#canonical_maps">canonical_maps</a> address mapping. 1246 By default, <a href="postconf.5.html#canonical_maps">canonical_maps</a> address mapping is applied to envelope 1247 sender and recipient addresses, and to header sender and header 1248 recipient addresses. </p> 1249 1250 <p> Specify one or more of: envelope_sender, envelope_recipient, 1251 header_sender, header_recipient </p> 1252 1253 <p> This feature is available in Postfix 2.2 and later. </p> 1254 1255 1256 </DD> 1257 1258 <DT><b><a name="canonical_maps">canonical_maps</a> 1259 (default: empty)</b></DT><DD> 1260 1261 <p> 1262 Optional address mapping lookup tables for message headers and 1263 envelopes. The mapping is applied to both sender and recipient 1264 addresses, in both envelopes and in headers, as controlled 1265 with the <a href="postconf.5.html#canonical_classes">canonical_classes</a> parameter. This is typically used 1266 to clean up dirty addresses from legacy mail systems, or to replace 1267 login names by Firstname.Lastname. The table format and lookups 1268 are documented in <a href="canonical.5.html">canonical(5)</a>. For an overview of Postfix address 1269 manipulations see the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> document. 1270 </p> 1271 1272 <p> 1273 If you use this feature, run "<b>postmap /etc/postfix/canonical</b>" to 1274 build the necessary DBM or DB file after every change. The changes 1275 will become visible after a minute or so. Use "<b>postfix reload</b>" 1276 to eliminate the delay. 1277 </p> 1278 1279 <p> Note: with Postfix version 2.2, message header address mapping 1280 happens only when message header address rewriting is enabled: </p> 1281 1282 <ul> 1283 1284 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 1285 1286 <li> The message is received from a network client that matches 1287 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 1288 1289 <li> The message is received from the network, and the 1290 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 1291 1292 </ul> 1293 1294 <p> To get the behavior before Postfix version 2.2, specify 1295 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 1296 1297 <p> 1298 Examples: 1299 </p> 1300 1301 <pre> 1302 <a href="postconf.5.html#canonical_maps">canonical_maps</a> = dbm:/etc/postfix/canonical 1303 <a href="postconf.5.html#canonical_maps">canonical_maps</a> = hash:/etc/postfix/canonical 1304 </pre> 1305 1306 1307 </DD> 1308 1309 <DT><b><a name="cleanup_service_name">cleanup_service_name</a> 1310 (default: cleanup)</b></DT><DD> 1311 1312 <p> 1313 The name of the <a href="cleanup.8.html">cleanup(8)</a> service. This service rewrites addresses 1314 into the standard form, and performs <a href="canonical.5.html">canonical(5)</a> address mapping 1315 and <a href="virtual.5.html">virtual(5)</a> aliasing. 1316 </p> 1317 1318 <p> 1319 This feature is available in Postfix 2.0 and later. 1320 </p> 1321 1322 1323 </DD> 1324 1325 <DT><b><a name="command_directory">command_directory</a> 1326 (default: see "postconf -d" output)</b></DT><DD> 1327 1328 <p> 1329 The location of all postfix administrative commands. 1330 </p> 1331 1332 1333 </DD> 1334 1335 <DT><b><a name="command_execution_directory">command_execution_directory</a> 1336 (default: empty)</b></DT><DD> 1337 1338 <p> The <a href="local.8.html">local(8)</a> delivery agent working directory for delivery to 1339 external command. Failure to change directory causes the delivery 1340 to be deferred. </p> 1341 1342 <p> The following $name expansions are done on <a href="postconf.5.html#command_execution_directory">command_execution_directory</a> 1343 before the directory is changed. Expansion happens in the context 1344 of the delivery request. The result of $name expansion is filtered 1345 with the character set that is specified with the 1346 <a href="postconf.5.html#execution_directory_expansion_filter">execution_directory_expansion_filter</a> parameter. </p> 1347 1348 <dl> 1349 1350 <dt><b>$user</b></dt> 1351 1352 <dd>The recipient's username. </dd> 1353 1354 <dt><b>$shell</b></dt> 1355 1356 <dd>The recipient's login shell pathname. </dd> 1357 1358 <dt><b>$home</b></dt> 1359 1360 <dd>The recipient's home directory. </dd> 1361 1362 <dt><b>$recipient</b></dt> 1363 1364 <dd>The full recipient address. </dd> 1365 1366 <dt><b>$extension</b></dt> 1367 1368 <dd>The optional recipient address extension. </dd> 1369 1370 <dt><b>$domain</b></dt> 1371 1372 <dd>The recipient domain. </dd> 1373 1374 <dt><b>$local</b></dt> 1375 1376 <dd>The entire recipient localpart. </dd> 1377 1378 <dt><b>$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b></dt> 1379 1380 <dd>The system-wide recipient address extension delimiter. </dd> 1381 1382 <dt><b>${name?value}</b></dt> 1383 1384 <dd>Expands to <i>value</i> when <i>$name</i> is non-empty. </dd> 1385 1386 <dt><b>${name:value}</b></dt> 1387 1388 <dd>Expands to <i>value</i> when <i>$name</i> is empty. </dd> 1389 1390 </dl> 1391 1392 <p> 1393 Instead of $name you can also specify ${name} or $(name). 1394 </p> 1395 1396 <p> This feature is available in Postfix 2.2 and later. </p> 1397 1398 1399 </DD> 1400 1401 <DT><b><a name="command_expansion_filter">command_expansion_filter</a> 1402 (default: see "postconf -d" output)</b></DT><DD> 1403 1404 <p> 1405 Restrict the characters that the <a href="local.8.html">local(8)</a> delivery agent allows in 1406 $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>. 1407 Characters outside the 1408 allowed set are replaced by underscores. 1409 </p> 1410 1411 1412 </DD> 1413 1414 <DT><b><a name="command_time_limit">command_time_limit</a> 1415 (default: 1000s)</b></DT><DD> 1416 1417 <p> 1418 Time limit for delivery to external commands. This limit is used 1419 by the <a href="local.8.html">local(8)</a> delivery agent, and is the default time limit for 1420 delivery by the <a href="pipe.8.html">pipe(8)</a> delivery agent. 1421 </p> 1422 1423 <p> 1424 Note: if you set this time limit to a large value you must update the 1425 global <a href="postconf.5.html#ipc_timeout">ipc_timeout</a> parameter as well. 1426 </p> 1427 1428 1429 </DD> 1430 1431 <DT><b><a name="config_directory">config_directory</a> 1432 (default: see "postconf -d" output)</b></DT><DD> 1433 1434 <p> The default location of the Postfix <a href="postconf.5.html">main.cf</a> and <a href="master.5.html">master.cf</a> 1435 configuration files. This can be overruled via the following 1436 mechanisms: </p> 1437 1438 <ul> 1439 1440 <li> <p> The MAIL_CONFIG environment variable (daemon processes 1441 and commands). </p> 1442 1443 <li> <p> The "-c" command-line option (commands only). </p> 1444 1445 </ul> 1446 1447 <p> With Postfix command that run with set-gid privileges, a 1448 <a href="postconf.5.html#config_directory">config_directory</a> override requires either root privileges, or it 1449 requires that the directory is listed with the <a href="postconf.5.html#alternate_config_directories">alternate_config_directories</a> 1450 parameter in the default <a href="postconf.5.html">main.cf</a> file. </p> 1451 1452 1453 </DD> 1454 1455 <DT><b><a name="connection_cache_protocol_timeout">connection_cache_protocol_timeout</a> 1456 (default: 5s)</b></DT><DD> 1457 1458 <p> Time limit for connection cache connect, send or receive 1459 operations. The time limit is enforced in the client. </p> 1460 1461 <p> This feature is available in Postfix 2.3 and later. </p> 1462 1463 1464 </DD> 1465 1466 <DT><b><a name="connection_cache_service_name">connection_cache_service_name</a> 1467 (default: scache)</b></DT><DD> 1468 1469 <p> The name of the <a href="scache.8.html">scache(8)</a> connection cache service. This service 1470 maintains a limited pool of cached sessions. </p> 1471 1472 <p> This feature is available in Postfix 2.2 and later. </p> 1473 1474 1475 </DD> 1476 1477 <DT><b><a name="connection_cache_status_update_time">connection_cache_status_update_time</a> 1478 (default: 600s)</b></DT><DD> 1479 1480 <p> How frequently the <a href="scache.8.html">scache(8)</a> server logs usage statistics with 1481 connection cache hit and miss rates for logical destinations and for 1482 physical endpoints. </p> 1483 1484 1485 </DD> 1486 1487 <DT><b><a name="connection_cache_ttl_limit">connection_cache_ttl_limit</a> 1488 (default: 2s)</b></DT><DD> 1489 1490 <p> The maximal time-to-live value that the <a href="scache.8.html">scache(8)</a> connection 1491 cache server 1492 allows. Requests that specify a larger TTL will be stored with the 1493 maximum allowed TTL. The purpose of this additional control is to 1494 protect the infrastructure against careless people. The cache TTL 1495 is already bounded by $<a href="postconf.5.html#max_idle">max_idle</a>. </p> 1496 1497 1498 </DD> 1499 1500 <DT><b><a name="content_filter">content_filter</a> 1501 (default: empty)</b></DT><DD> 1502 1503 <p> 1504 The name of a mail delivery transport that filters mail after 1505 it is queued. 1506 </p> 1507 1508 <p> 1509 This parameter uses the same syntax as the right-hand side of a 1510 Postfix <a href="transport.5.html">transport(5)</a> table. This setting has a lower precedence 1511 than a content filter that is specified with an <a href="access.5.html">access(5)</a> table or 1512 in a <a href="header_checks.5.html">header_checks(5)</a> or <a href="header_checks.5.html">body_checks(5)</a> table. 1513 </p> 1514 1515 1516 </DD> 1517 1518 <DT><b><a name="cyrus_sasl_config_path">cyrus_sasl_config_path</a> 1519 (default: empty)</b></DT><DD> 1520 1521 <p> Search path for Cyrus SASL application configuration files, 1522 currently used only to locate the $<a href="postconf.5.html#smtpd_sasl_path">smtpd_sasl_path</a>.conf file. 1523 Specify zero or more directories separated by a colon character, 1524 or an empty value to use Cyrus SASL's built-in search path. </p> 1525 1526 <p> This feature is available in Postfix 2.5 and later when compiled 1527 with Cyrus SASL 2.1.22 or later. </p> 1528 1529 1530 </DD> 1531 1532 <DT><b><a name="daemon_directory">daemon_directory</a> 1533 (default: see "postconf -d" output)</b></DT><DD> 1534 1535 <p> 1536 The directory with Postfix support programs and daemon programs. 1537 These should not be invoked directly by humans. The directory must 1538 be owned by root. 1539 </p> 1540 1541 1542 </DD> 1543 1544 <DT><b><a name="daemon_timeout">daemon_timeout</a> 1545 (default: 18000s)</b></DT><DD> 1546 1547 <p> How much time a Postfix daemon process may take to handle a 1548 request before it is terminated by a built-in watchdog timer. </p> 1549 1550 <p> 1551 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 1552 The default time unit is s (seconds). 1553 </p> 1554 1555 1556 </DD> 1557 1558 <DT><b><a name="data_directory">data_directory</a> 1559 (default: see "postconf -d" output)</b></DT><DD> 1560 1561 <p> The directory with Postfix-writable data files (for example: 1562 caches, pseudo-random numbers). This directory must be owned by 1563 the <a href="postconf.5.html#mail_owner">mail_owner</a> account, and must not be shared with non-Postfix 1564 software. </p> 1565 1566 <p> This feature is available in Postfix 2.5 and later. </p> 1567 1568 1569 </DD> 1570 1571 <DT><b><a name="debug_peer_level">debug_peer_level</a> 1572 (default: 2)</b></DT><DD> 1573 1574 <p> The increment in verbose logging level when a remote client or 1575 server matches a pattern in the <a href="postconf.5.html#debug_peer_list">debug_peer_list</a> parameter. </p> 1576 1577 1578 </DD> 1579 1580 <DT><b><a name="debug_peer_list">debug_peer_list</a> 1581 (default: empty)</b></DT><DD> 1582 1583 <p> Optional list of remote client or server hostname or network 1584 address patterns that cause the verbose logging level to increase 1585 by the amount specified in $<a href="postconf.5.html#debug_peer_level">debug_peer_level</a>. </p> 1586 1587 <p> Specify domain names, network/netmask patterns, "/file/name" 1588 patterns or "<a href="DATABASE_README.html">type:table</a>" lookup tables. The right-hand side result 1589 from "<a href="DATABASE_README.html">type:table</a>" lookups is ignored. </p> 1590 1591 <p> Pattern matching of domain names is controlled by the 1592 <a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> parameter. </p> 1593 1594 <p> 1595 Examples: 1596 </p> 1597 1598 <pre> 1599 <a href="postconf.5.html#debug_peer_list">debug_peer_list</a> = 127.0.0.1 1600 <a href="postconf.5.html#debug_peer_list">debug_peer_list</a> = example.com 1601 </pre> 1602 1603 1604 </DD> 1605 1606 <DT><b><a name="debugger_command">debugger_command</a> 1607 (default: empty)</b></DT><DD> 1608 1609 <p> 1610 The external command to execute when a Postfix daemon program is 1611 invoked with the -D option. 1612 </p> 1613 1614 <p> 1615 Use "command .. & sleep 5" so that the debugger can attach before 1616 the process marches on. If you use an X-based debugger, be sure to 1617 set up your XAUTHORITY environment variable before starting Postfix. 1618 </p> 1619 1620 <p> 1621 Example: 1622 </p> 1623 1624 <pre> 1625 <a href="postconf.5.html#debugger_command">debugger_command</a> = 1626 PATH=/usr/bin:/usr/X11R6/bin 1627 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 1628 </pre> 1629 1630 1631 </DD> 1632 1633 <DT><b><a name="default_database_type">default_database_type</a> 1634 (default: see "postconf -d" output)</b></DT><DD> 1635 1636 <p> 1637 The default database type for use in <a href="newaliases.1.html">newaliases(1)</a>, <a href="postalias.1.html">postalias(1)</a> 1638 and <a href="postmap.1.html">postmap(1)</a> commands. On many UNIX systems the default type is 1639 either <b>dbm</b> or <b>hash</b>. The default setting is frozen 1640 when the Postfix system is built. 1641 </p> 1642 1643 <p> 1644 Examples: 1645 </p> 1646 1647 <pre> 1648 <a href="postconf.5.html#default_database_type">default_database_type</a> = hash 1649 <a href="postconf.5.html#default_database_type">default_database_type</a> = dbm 1650 </pre> 1651 1652 1653 </DD> 1654 1655 <DT><b><a name="default_delivery_slot_cost">default_delivery_slot_cost</a> 1656 (default: 5)</b></DT><DD> 1657 1658 <p> 1659 How often the Postfix queue manager's scheduler is allowed to 1660 preempt delivery of one message with another. 1661 </p> 1662 1663 <p> 1664 Each transport maintains a so-called "available delivery slot counter" 1665 for each message. One message can be preempted by another one when 1666 the other message can be delivered using no more delivery slots 1667 (i.e., invocations of delivery agents) than the current message 1668 counter has accumulated (or will eventually accumulate - see about 1669 slot loans below). This parameter controls how often is the counter 1670 incremented - it happens after each <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> 1671 recipients have been delivered. 1672 </p> 1673 1674 <p> 1675 The cost of 0 is used to disable the preempting scheduling completely. 1676 The minimum value the scheduling algorithm can use is 2 - use it 1677 if you want to maximize the message throughput rate. Although there 1678 is no maximum, it doesn't make much sense to use values above say 1679 50. 1680 </p> 1681 1682 <p> 1683 The only reason why the value of 2 is not the default is the way 1684 this parameter affects the delivery of mailing-list mail. In the 1685 worst case, their delivery can take somewhere between (cost+1/cost) 1686 and (cost/cost-1) times more than if the preemptive scheduler was 1687 disabled. The default value of 5 turns out to provide reasonable 1688 message response times while making sure the mailing-list deliveries 1689 are not extended by more than 20-25 percent even in the worst case. 1690 </p> 1691 1692 <p> Use <a href="postconf.5.html#transport_delivery_slot_cost"><i>transport</i>_delivery_slot_cost</a> to specify a 1693 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1694 name of the message delivery transport. 1695 </p> 1696 1697 <p> 1698 Examples: 1699 </p> 1700 1701 <pre> 1702 <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> = 0 1703 <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> = 2 1704 </pre> 1705 1706 1707 </DD> 1708 1709 <DT><b><a name="default_delivery_slot_discount">default_delivery_slot_discount</a> 1710 (default: 50)</b></DT><DD> 1711 1712 <p> 1713 The default value for transport-specific _delivery_slot_discount 1714 settings. 1715 </p> 1716 1717 <p> 1718 This parameter speeds up the moment when a message preemption can 1719 happen. Instead of waiting until the full amount of delivery slots 1720 required is available, the preemption can happen when 1721 transport_delivery_slot_discount percent of the required amount 1722 plus transport_delivery_slot_loan still remains to be accumulated. 1723 Note that the full amount will still have to be accumulated before 1724 another preemption can take place later. 1725 </p> 1726 1727 <p> Use <a href="postconf.5.html#transport_delivery_slot_discount"><i>transport</i>_delivery_slot_discount</a> to specify a 1728 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1729 name of the message delivery transport. 1730 </p> 1731 1732 1733 </DD> 1734 1735 <DT><b><a name="default_delivery_slot_loan">default_delivery_slot_loan</a> 1736 (default: 3)</b></DT><DD> 1737 1738 <p> 1739 The default value for transport-specific _delivery_slot_loan 1740 settings. 1741 </p> 1742 1743 <p> 1744 This parameter speeds up the moment when a message preemption can 1745 happen. Instead of waiting until the full amount of delivery slots 1746 required is available, the preemption can happen when 1747 transport_delivery_slot_discount percent of the required amount 1748 plus transport_delivery_slot_loan still remains to be accumulated. 1749 Note that the full amount will still have to be accumulated before 1750 another preemption can take place later. 1751 </p> 1752 1753 <p> Use <a href="postconf.5.html#transport_delivery_slot_loan"><i>transport</i>_delivery_slot_loan</a> to specify a 1754 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1755 name of the message delivery transport. 1756 </p> 1757 1758 1759 </DD> 1760 1761 <DT><b><a name="default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a> 1762 (default: 1)</b></DT><DD> 1763 1764 <p> How many pseudo-cohorts must suffer connection or handshake 1765 failure before a specific destination is considered unavailable 1766 (and further delivery is suspended). Specify zero to disable this 1767 feature. A destination's pseudo-cohort failure count is reset each 1768 time a delivery completes without connection or handshake failure 1769 for that specific destination. </p> 1770 1771 <p> A pseudo-cohort is the number of deliveries equal to a destination's 1772 delivery concurrency. </p> 1773 1774 <p> Use <a href="postconf.5.html#transport_destination_concurrency_failed_cohort_limit"><i>transport</i>_destination_concurrency_failed_cohort_limit</a> to specify 1775 a transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1776 name of the message delivery transport. </p> 1777 1778 <p> This feature is available in Postfix 2.5. The default setting 1779 is compatible with earlier Postfix versions. </p> 1780 1781 1782 </DD> 1783 1784 <DT><b><a name="default_destination_concurrency_limit">default_destination_concurrency_limit</a> 1785 (default: 20)</b></DT><DD> 1786 1787 <p> 1788 The default maximal number of parallel deliveries to the same 1789 destination. This is the default limit for delivery via the <a href="lmtp.8.html">lmtp(8)</a>, 1790 <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. 1791 With per-destination recipient limit > 1, a destination is a domain, 1792 otherwise it is a recipient. 1793 </p> 1794 1795 <p> Use <a href="postconf.5.html#transport_destination_concurrency_limit"><i>transport</i>_destination_concurrency_limit</a> to specify a 1796 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1797 name of the message delivery transport. 1798 </p> 1799 1800 1801 </DD> 1802 1803 <DT><b><a name="default_destination_concurrency_negative_feedback">default_destination_concurrency_negative_feedback</a> 1804 (default: 1)</b></DT><DD> 1805 1806 <p> The per-destination amount of delivery concurrency negative 1807 feedback, after a delivery completes with a connection or handshake 1808 failure. Feedback values are in the range 0..1 inclusive. With 1809 negative feedback, concurrency is decremented at the beginning of 1810 a sequence of length 1/feedback. This is unlike positive feedback, 1811 where concurrency is incremented at the end of a sequence of length 1812 1/feedback. </p> 1813 1814 <p> As of Postfix version 2.5, negative feedback cannot reduce 1815 delivery concurrency to zero. Instead, a destination is marked 1816 dead (further delivery suspended) after the failed pseudo-cohort 1817 count reaches $<a href="postconf.5.html#default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a> 1818 (or $<a href="postconf.5.html#transport_destination_concurrency_failed_cohort_limit"><i>transport</i>_destination_concurrency_failed_cohort_limit</a>). 1819 To make the scheduler completely immune to connection or handshake 1820 failures, specify a zero feedback value and a zero failed pseudo-cohort 1821 limit. </p> 1822 1823 <p> Specify one of the following forms: </p> 1824 1825 <dl> 1826 1827 <dt> <b><i>number</i> </b> </dt> 1828 1829 <dt> <b><i>number</i> / <i>number</i> </b> </dt> 1830 1831 <dd> Constant feedback. The value must be in the range 0..1 inclusive. 1832 The default setting of "1" is compatible with Postfix versions 1833 before 2.5, where a destination's delivery concurrency is throttled 1834 down to zero (and further delivery suspended) after a single failed 1835 pseudo-cohort. </dd> 1836 1837 <dt> <b><i>number</i> / concurrency </b> </dt> 1838 1839 <dd> Variable feedback of "<i>number</i> / (delivery concurrency)". 1840 The <i>number</i> must be in the range 0..1 inclusive. With 1841 <i>number</i> equal to "1", a destination's delivery concurrency 1842 is decremented by 1 after each failed pseudo-cohort. </dd> 1843 1844 </dl> 1845 1846 <p> A pseudo-cohort is the number of deliveries equal to a destination's 1847 delivery concurrency. </p> 1848 1849 <p> Use <a href="postconf.5.html#transport_destination_concurrency_negative_feedback"><i>transport</i>_destination_concurrency_negative_feedback</a> 1850 to specify a transport-specific override, where <i>transport</i> 1851 is the <a href="master.5.html">master.cf</a> 1852 name of the message delivery transport. </p> 1853 1854 <p> This feature is available in Postfix 2.5. The default setting 1855 is compatible with earlier Postfix versions. </p> 1856 1857 1858 </DD> 1859 1860 <DT><b><a name="default_destination_concurrency_positive_feedback">default_destination_concurrency_positive_feedback</a> 1861 (default: 1)</b></DT><DD> 1862 1863 <p> The per-destination amount of delivery concurrency positive 1864 feedback, after a delivery completes without connection or handshake 1865 failure. Feedback values are in the range 0..1 inclusive. The 1866 concurrency increases until it reaches the per-destination maximal 1867 concurrency limit. With positive feedback, concurrency is incremented 1868 at the end of a sequence with length 1/feedback. This is unlike 1869 negative feedback, where concurrency is decremented at the start 1870 of a sequence of length 1/feedback. </p> 1871 1872 <p> Specify one of the following forms: </p> 1873 1874 <dl> 1875 1876 <dt> <b><i>number</i> </b> </dt> 1877 1878 <dt> <b><i>number</i> / <i>number</i> </b> </dt> 1879 1880 <dd> Constant feedback. The value must be in the range 0..1 1881 inclusive. The default setting of "1" is compatible with Postfix 1882 versions before 2.5, where a destination's delivery concurrency 1883 doubles after each successful pseudo-cohort. </dd> 1884 1885 <dt> <b><i>number</i> / concurrency </b> </dt> 1886 1887 <dd> Variable feedback of "<i>number</i> / (delivery concurrency)". 1888 The <i>number</i> must be in the range 0..1 inclusive. With 1889 <i>number</i> equal to "1", a destination's delivery concurrency 1890 is incremented by 1 after each successful pseudo-cohort. </dd> 1891 1892 </dl> 1893 1894 <p> A pseudo-cohort is the number of deliveries equal to a destination's 1895 delivery concurrency. </p> 1896 1897 <p> Use <a href="postconf.5.html#transport_destination_concurrency_positive_feedback"><i>transport</i>_destination_concurrency_positive_feedback</a> 1898 to specify a transport-specific override, where <i>transport</i> 1899 is the <a href="master.5.html">master.cf</a> name of the message delivery transport. </p> 1900 1901 <p> This feature is available in Postfix 2.5 and later. </p> 1902 1903 1904 </DD> 1905 1906 <DT><b><a name="default_destination_rate_delay">default_destination_rate_delay</a> 1907 (default: 0s)</b></DT><DD> 1908 1909 <p> The default amount of delay that is inserted between individual 1910 deliveries to the same destination; with per-destination recipient 1911 limit > 1, a destination is a domain, otherwise it is a recipient. 1912 </p> 1913 1914 <p> To enable the delay, specify a non-zero time value (an integral 1915 value plus an optional one-letter suffix that specifies the time 1916 unit). </p> 1917 1918 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 1919 (weeks). The default time unit is s (seconds). </p> 1920 1921 <p> NOTE: the delay is enforced by the queue manager. The delay 1922 timer state does not survive "postfix reload" or "postfix stop". 1923 </p> 1924 1925 <p> Use <a href="postconf.5.html#transport_destination_rate_delay"><i>transport</i>_destination_rate_delay</a> to specify a 1926 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1927 name of the message delivery transport. 1928 </p> 1929 1930 <p> This feature is available in Postfix 2.5 and later. </p> 1931 1932 1933 </DD> 1934 1935 <DT><b><a name="default_destination_recipient_limit">default_destination_recipient_limit</a> 1936 (default: 50)</b></DT><DD> 1937 1938 <p> 1939 The default maximal number of recipients per message delivery. 1940 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>, 1941 <a href="smtp.8.html">smtp(8)</a> and <a href="virtual.8.html">virtual(8)</a> delivery agents. 1942 </p> 1943 1944 <p> Setting this parameter to a value of 1 changes the meaning of 1945 the corresponding per-destination concurrency limit from concurrency 1946 per domain into concurrency per recipient. </p> 1947 1948 <p> Use <a href="postconf.5.html#transport_destination_recipient_limit"><i>transport</i>_destination_recipient_limit</a> to specify a 1949 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1950 name of the message delivery transport. 1951 </p> 1952 1953 1954 </DD> 1955 1956 <DT><b><a name="default_extra_recipient_limit">default_extra_recipient_limit</a> 1957 (default: 1000)</b></DT><DD> 1958 1959 <p> 1960 The default value for the extra per-transport limit imposed on the 1961 number of in-memory recipients. This extra recipient space is 1962 reserved for the cases when the Postfix queue manager's scheduler 1963 preempts one message with another and suddenly needs some extra 1964 recipients slots for the chosen message in order to avoid performance 1965 degradation. 1966 </p> 1967 1968 <p> Use <a href="postconf.5.html#transport_extra_recipient_limit"><i>transport</i>_extra_recipient_limit</a> to specify a 1969 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1970 name of the message delivery transport. 1971 </p> 1972 1973 1974 </DD> 1975 1976 <DT><b><a name="default_minimum_delivery_slots">default_minimum_delivery_slots</a> 1977 (default: 3)</b></DT><DD> 1978 1979 <p> 1980 How many recipients a message must have in order to invoke the 1981 Postfix queue manager's scheduling algorithm at all. Messages 1982 which would never accumulate at least this many delivery slots 1983 (subject to slot cost parameter as well) are never preempted. 1984 </p> 1985 1986 <p> Use <a href="postconf.5.html#transport_minimum_delivery_slots"><i>transport</i>_minimum_delivery_slots</a> to specify a 1987 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 1988 name of the message delivery transport. 1989 </p> 1990 1991 1992 </DD> 1993 1994 <DT><b><a name="default_privs">default_privs</a> 1995 (default: nobody)</b></DT><DD> 1996 1997 <p> 1998 The default rights used by the <a href="local.8.html">local(8)</a> delivery agent for delivery 1999 to external file or command. These rights are used when delivery 2000 is requested from an <a href="aliases.5.html">aliases(5)</a> file that is owned by <b>root</b>, or 2001 when delivery is done on behalf of <b>root</b>. <b>DO NOT SPECIFY A 2002 PRIVILEGED USER OR THE POSTFIX OWNER</b>. 2003 </p> 2004 2005 2006 </DD> 2007 2008 <DT><b><a name="default_process_limit">default_process_limit</a> 2009 (default: 100)</b></DT><DD> 2010 2011 <p> 2012 The default maximal number of Postfix child processes that provide 2013 a given service. This limit can be overruled for specific services 2014 in the <a href="master.5.html">master.cf</a> file. 2015 </p> 2016 2017 2018 </DD> 2019 2020 <DT><b><a name="default_rbl_reply">default_rbl_reply</a> 2021 (default: see "postconf -d" output)</b></DT><DD> 2022 2023 <p> 2024 The default SMTP server response template for a request that is 2025 rejected by an RBL-based restriction. This template can be overruled 2026 by specific entries in the optional <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> lookup table. 2027 </p> 2028 2029 <p> 2030 This feature is available in Postfix 2.0 and later. 2031 </p> 2032 2033 <p> 2034 The template is subject to exactly one level of $name substitution: 2035 </p> 2036 2037 <dl> 2038 2039 <dt><b>$client</b></dt> 2040 2041 <dd>The client hostname and IP address, formatted as name[address]. </dd> 2042 2043 <dt><b>$client_address</b></dt> 2044 2045 <dd>The client IP address. </dd> 2046 2047 <dt><b>$client_name</b></dt> 2048 2049 <dd>The client hostname or "unknown". See <a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> 2050 for more details. </dd> 2051 2052 <dt><b>$reverse_client_name</b></dt> 2053 2054 <dd>The client hostname from address->name lookup, or "unknown". 2055 See <a href="postconf.5.html#reject_unknown_reverse_client_hostname">reject_unknown_reverse_client_hostname</a> for more details. </dd> 2056 2057 <dt><b>$helo_name</b></dt> 2058 2059 <dd>The hostname given in HELO or EHLO command or empty string. </dd> 2060 2061 <dt><b>$rbl_class</b></dt> 2062 2063 <dd>The blacklisted entity type: Client host, Helo command, Sender 2064 address, or Recipient address. </dd> 2065 2066 <dt><b>$rbl_code</b></dt> 2067 2068 <dd>The numerical SMTP response code, as specified with the 2069 <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> configuration parameter. Note: The numerical 2070 SMTP response code is required, and must appear at the start of the 2071 reply. With Postfix version 2.3 and later this information may be followed 2072 by an <a href="http://tools.ietf.org/html/rfc3463">RFC 3463</a> enhanced status code. </dd> 2073 2074 <dt><b>$rbl_domain</b></dt> 2075 2076 <dd>The RBL domain where $rbl_what is blacklisted. </dd> 2077 2078 <dt><b>$rbl_reason</b></dt> 2079 2080 <dd>The reason why $rbl_what is blacklisted, or an empty string. </dd> 2081 2082 <dt><b>$rbl_what</b></dt> 2083 2084 <dd>The entity that is blacklisted (an IP address, a hostname, a domain 2085 name, or an email address whose domain was blacklisted). </dd> 2086 2087 <dt><b>$recipient</b></dt> 2088 2089 <dd>The recipient address or <> in case of the null address. </dd> 2090 2091 <dt><b>$recipient_domain</b></dt> 2092 2093 <dd>The recipient domain or empty string. </dd> 2094 2095 <dt><b>$recipient_name</b></dt> 2096 2097 <dd>The recipient address localpart or <> in case of null address. </dd> 2098 2099 <dt><b>$sender</b></dt> 2100 2101 <dd>The sender address or <> in case of the null address. </dd> 2102 2103 <dt><b>$sender_domain</b></dt> 2104 2105 <dd>The sender domain or empty string. </dd> 2106 2107 <dt><b>$sender_name</b></dt> 2108 2109 <dd>The sender address localpart or <> in case of the null address. </dd> 2110 2111 <dt><b>${name?text}</b></dt> 2112 2113 <dd>Expands to `text' if $name is not empty. </dd> 2114 2115 <dt><b>${name:text}</b></dt> 2116 2117 <dd>Expands to `text' if $name is empty. </dd> 2118 2119 </dl> 2120 2121 <p> 2122 Instead of $name you can also specify ${name} or $(name). 2123 </p> 2124 2125 <p> Note: when an enhanced status code is specified in an RBL reply 2126 template, it is subject to modification. The following transformations 2127 are needed when the same RBL reply template is used for client, 2128 helo, sender, or recipient access restrictions. </p> 2129 2130 <ul> 2131 2132 <li> <p> When rejecting a sender address, the Postfix SMTP server 2133 will transform a recipient DSN status (e.g., 4.1.1-4.1.6) into the 2134 corresponding sender DSN status, and vice versa. </p> 2135 2136 <li> <p> When rejecting non-address information (such as the HELO 2137 command argument or the client hostname/address), the Postfix SMTP 2138 server will transform a sender or recipient DSN status into a generic 2139 non-address DSN status (e.g., 4.0.0). </p> 2140 2141 </ul> 2142 2143 2144 </DD> 2145 2146 <DT><b><a name="default_recipient_limit">default_recipient_limit</a> 2147 (default: 20000)</b></DT><DD> 2148 2149 <p> 2150 The default per-transport upper limit on the number of in-memory 2151 recipients. These limits take priority over the global 2152 <a href="postconf.5.html#qmgr_message_recipient_limit">qmgr_message_recipient_limit</a> after the message has been assigned 2153 to the respective transports. See also <a href="postconf.5.html#default_extra_recipient_limit">default_extra_recipient_limit</a> 2154 and <a href="postconf.5.html#qmgr_message_recipient_minimum">qmgr_message_recipient_minimum</a>. 2155 </p> 2156 2157 <p> Use <a href="postconf.5.html#transport_recipient_limit"><i>transport</i>_recipient_limit</a> to specify a 2158 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 2159 name of the message delivery transport. 2160 </p> 2161 2162 2163 </DD> 2164 2165 <DT><b><a name="default_recipient_refill_delay">default_recipient_refill_delay</a> 2166 (default: 5s)</b></DT><DD> 2167 2168 <p> 2169 The default per-transport maximum delay between recipients refills. 2170 When not all message recipients fit into the memory at once, keep loading 2171 more of them at least once every this many seconds. This is used to 2172 make sure the recipients are refilled in timely manner even when 2173 $<a href="postconf.5.html#default_recipient_refill_limit">default_recipient_refill_limit</a> is too high for too slow deliveries. 2174 </p> 2175 2176 <p> Use <a href="postconf.5.html#transport_recipient_refill_delay"><i>transport</i>_recipient_refill_delay</a> to specify a 2177 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 2178 name of the message delivery transport. 2179 </p> 2180 2181 <p> This feature is available in Postfix 2.4 and later. </p> 2182 2183 2184 </DD> 2185 2186 <DT><b><a name="default_recipient_refill_limit">default_recipient_refill_limit</a> 2187 (default: 100)</b></DT><DD> 2188 2189 <p> 2190 The default per-transport limit on the number of recipients refilled at 2191 once. When not all message recipients fit into the memory at once, keep 2192 loading more of them in batches of at least this many at a time. See also 2193 $<a href="postconf.5.html#default_recipient_refill_delay">default_recipient_refill_delay</a>, which may result in recipient batches 2194 lower than this when this limit is too high for too slow deliveries. 2195 </p> 2196 2197 <p> Use <a href="postconf.5.html#transport_recipient_refill_limit"><i>transport</i>_recipient_refill_limit</a> to specify a 2198 transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 2199 name of the message delivery transport. 2200 </p> 2201 2202 <p> This feature is available in Postfix 2.4 and later. </p> 2203 2204 2205 </DD> 2206 2207 <DT><b><a name="default_transport">default_transport</a> 2208 (default: smtp)</b></DT><DD> 2209 2210 <p> 2211 The default mail delivery transport and next-hop destination for 2212 destinations that do not match $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>, 2213 $<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>, 2214 or $<a href="postconf.5.html#relay_domains">relay_domains</a>. In order of decreasing precedence, the nexthop 2215 destination is taken from $<a href="postconf.5.html#default_transport">default_transport</a>, 2216 $<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 2217 domain. This information can be overruled with the <a href="transport.5.html">transport(5)</a> 2218 table. 2219 </p> 2220 2221 <p> 2222 Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i> 2223 is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>. 2224 The <i>:nexthop</i> part is optional. For more details see the 2225 <a href="transport.5.html">transport(5)</a> manual page. 2226 </p> 2227 2228 <p> 2229 Example: 2230 </p> 2231 2232 <pre> 2233 <a href="postconf.5.html#default_transport">default_transport</a> = uucp:relayhostname 2234 </pre> 2235 2236 2237 </DD> 2238 2239 <DT><b><a name="default_verp_delimiters">default_verp_delimiters</a> 2240 (default: +=)</b></DT><DD> 2241 2242 <p> The two default VERP delimiter characters. These are used when 2243 no explicit delimiters are specified with the SMTP XVERP command 2244 or with the "<b>sendmail -V</b>" command-line option. Specify 2245 characters that are allowed by the <a href="postconf.5.html#verp_delimiter_filter">verp_delimiter_filter</a> setting. 2246 </p> 2247 2248 <p> 2249 This feature is available in Postfix 1.1 and later. 2250 </p> 2251 2252 2253 </DD> 2254 2255 <DT><b><a name="defer_code">defer_code</a> 2256 (default: 450)</b></DT><DD> 2257 2258 <p> 2259 The numerical Postfix SMTP server response code when a remote SMTP 2260 client request is rejected by the "defer" restriction. 2261 </p> 2262 2263 <p> 2264 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 2265 </p> 2266 2267 2268 </DD> 2269 2270 <DT><b><a name="defer_service_name">defer_service_name</a> 2271 (default: defer)</b></DT><DD> 2272 2273 <p> 2274 The name of the defer service. This service is implemented by the 2275 <a href="bounce.8.html">bounce(8)</a> daemon and maintains a record 2276 of failed delivery attempts and generates non-delivery notifications. 2277 </p> 2278 2279 <p> 2280 This feature is available in Postfix 2.0 and later. 2281 </p> 2282 2283 2284 </DD> 2285 2286 <DT><b><a name="defer_transports">defer_transports</a> 2287 (default: empty)</b></DT><DD> 2288 2289 <p> 2290 The names of message delivery transports that should not deliver mail 2291 unless someone issues "<b>sendmail -q</b>" or equivalent. Specify zero 2292 or more names of mail delivery transports names that appear in the 2293 first field of <a href="master.5.html">master.cf</a>. 2294 </p> 2295 2296 <p> 2297 Example: 2298 </p> 2299 2300 <pre> 2301 <a href="postconf.5.html#defer_transports">defer_transports</a> = smtp 2302 </pre> 2303 2304 2305 </DD> 2306 2307 <DT><b><a name="delay_logging_resolution_limit">delay_logging_resolution_limit</a> 2308 (default: 2)</b></DT><DD> 2309 2310 <p> The maximal number of digits after the decimal point when logging 2311 sub-second delay values. Specify a number in the range 0..6. </p> 2312 2313 <p> Large delay values are rounded off to an integral number seconds; 2314 delay values below the <a href="postconf.5.html#delay_logging_resolution_limit">delay_logging_resolution_limit</a> are logged 2315 as "0", and small delay values are logged with at most two-digit 2316 precision. </p> 2317 2318 <p> The format of the "delays=a/b/c/d" logging is as follows: </p> 2319 2320 <ul> 2321 2322 <li> a = time from message arrival to last <a href="QSHAPE_README.html#active_queue">active queue</a> entry 2323 2324 <li> b = time from last <a href="QSHAPE_README.html#active_queue">active queue</a> entry to connection setup 2325 2326 <li> c = time in connection setup, including DNS, EHLO and TLS 2327 2328 <li> d = time in message transmission 2329 2330 </ul> 2331 2332 <p> This feature is available in Postfix 2.3 and later. </p> 2333 2334 2335 </DD> 2336 2337 <DT><b><a name="delay_notice_recipient">delay_notice_recipient</a> 2338 (default: postmaster)</b></DT><DD> 2339 2340 <p> 2341 The recipient of postmaster notifications with the message headers 2342 of mail that cannot be delivered within $<a href="postconf.5.html#delay_warning_time">delay_warning_time</a> time 2343 units. </p> 2344 2345 <p> 2346 This feature is enabled with the <a href="postconf.5.html#delay_warning_time">delay_warning_time</a> parameter. 2347 </p> 2348 2349 2350 </DD> 2351 2352 <DT><b><a name="delay_warning_time">delay_warning_time</a> 2353 (default: 0h)</b></DT><DD> 2354 2355 <p> 2356 The time after which the sender receives the message headers of 2357 mail that is still queued. 2358 </p> 2359 2360 <p> 2361 To enable this feature, specify a non-zero time value (an integral 2362 value plus an optional one-letter suffix that specifies the time 2363 unit). 2364 </p> 2365 2366 <p> 2367 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 2368 The default time unit is h (hours). 2369 </p> 2370 2371 2372 </DD> 2373 2374 <DT><b><a name="deliver_lock_attempts">deliver_lock_attempts</a> 2375 (default: 20)</b></DT><DD> 2376 2377 <p> 2378 The maximal number of attempts to acquire an exclusive lock on a 2379 mailbox file or <a href="bounce.8.html">bounce(8)</a> logfile. 2380 </p> 2381 2382 2383 </DD> 2384 2385 <DT><b><a name="deliver_lock_delay">deliver_lock_delay</a> 2386 (default: 1s)</b></DT><DD> 2387 2388 <p> 2389 The time between attempts to acquire an exclusive lock on a mailbox 2390 file or <a href="bounce.8.html">bounce(8)</a> logfile. 2391 </p> 2392 2393 <p> 2394 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 2395 The default time unit is s (seconds). 2396 </p> 2397 2398 2399 </DD> 2400 2401 <DT><b><a name="destination_concurrency_feedback_debug">destination_concurrency_feedback_debug</a> 2402 (default: no)</b></DT><DD> 2403 2404 <p> Make the queue manager's feedback algorithm verbose for performance 2405 analysis purposes. </p> 2406 2407 <p> This feature is available in Postfix 2.5 and later. </p> 2408 2409 2410 </DD> 2411 2412 <DT><b><a name="detect_8bit_encoding_header">detect_8bit_encoding_header</a> 2413 (default: yes)</b></DT><DD> 2414 2415 <p> Automatically detect 8BITMIME body content by looking at 2416 Content-Transfer-Encoding: message headers; historically, this 2417 behavior was hard-coded to be "always on". </p> 2418 2419 <p> This feature is available in Postfix 2.5 and later. </p> 2420 2421 2422 </DD> 2423 2424 <DT><b><a name="disable_dns_lookups">disable_dns_lookups</a> 2425 (default: no)</b></DT><DD> 2426 2427 <p> 2428 Disable DNS lookups in the Postfix SMTP and LMTP clients. When 2429 disabled, hosts are looked up with the getaddrinfo() system 2430 library routine which normally also looks in /etc/hosts. 2431 </p> 2432 2433 <p> 2434 DNS lookups are enabled by default. 2435 </p> 2436 2437 2438 </DD> 2439 2440 <DT><b><a name="disable_mime_input_processing">disable_mime_input_processing</a> 2441 (default: no)</b></DT><DD> 2442 2443 <p> 2444 Turn off MIME processing while receiving mail. This means that no 2445 special treatment is given to Content-Type: message headers, and 2446 that all text after the initial message headers is considered to 2447 be part of the message body. 2448 </p> 2449 2450 <p> 2451 This feature is available in Postfix 2.0 and later. 2452 </p> 2453 2454 <p> 2455 Mime input processing is enabled by default, and is needed in order 2456 to recognize MIME headers in message content. 2457 </p> 2458 2459 2460 </DD> 2461 2462 <DT><b><a name="disable_mime_output_conversion">disable_mime_output_conversion</a> 2463 (default: no)</b></DT><DD> 2464 2465 <p> 2466 Disable the conversion of 8BITMIME format to 7BIT format. Mime 2467 output conversion is needed when the destination does not advertise 2468 8BITMIME support. 2469 </p> 2470 2471 <p> 2472 This feature is available in Postfix 2.0 and later. 2473 </p> 2474 2475 2476 </DD> 2477 2478 <DT><b><a name="disable_verp_bounces">disable_verp_bounces</a> 2479 (default: no)</b></DT><DD> 2480 2481 <p> 2482 Disable sending one bounce report per recipient. 2483 </p> 2484 2485 <p> 2486 The default, one per recipient, is what ezmlm needs. 2487 </p> 2488 2489 <p> 2490 This feature is available in Postfix 1.1 and later. 2491 </p> 2492 2493 2494 </DD> 2495 2496 <DT><b><a name="disable_vrfy_command">disable_vrfy_command</a> 2497 (default: no)</b></DT><DD> 2498 2499 <p> 2500 Disable the SMTP VRFY command. This stops some techniques used to 2501 harvest email addresses. 2502 </p> 2503 2504 <p> 2505 Example: 2506 </p> 2507 2508 <pre> 2509 <a href="postconf.5.html#disable_vrfy_command">disable_vrfy_command</a> = no 2510 </pre> 2511 2512 2513 </DD> 2514 2515 <DT><b><a name="dont_remove">dont_remove</a> 2516 (default: 0)</b></DT><DD> 2517 2518 <p> 2519 Don't remove queue files and save them to the "saved" mail queue. 2520 This is a debugging aid. To inspect the envelope information and 2521 content of a Postfix queue file, use the <a href="postcat.1.html">postcat(1)</a> command. 2522 </p> 2523 2524 2525 </DD> 2526 2527 <DT><b><a name="double_bounce_sender">double_bounce_sender</a> 2528 (default: double-bounce)</b></DT><DD> 2529 2530 <p> The sender address of postmaster notifications that are generated 2531 by the mail system. All mail to this address is silently discarded, 2532 in order to terminate mail bounce loops. </p> 2533 2534 2535 </DD> 2536 2537 <DT><b><a name="duplicate_filter_limit">duplicate_filter_limit</a> 2538 (default: 1000)</b></DT><DD> 2539 2540 <p> The maximal number of addresses remembered by the address 2541 duplicate filter for <a href="aliases.5.html">aliases(5)</a> or <a href="virtual.5.html">virtual(5)</a> alias expansion, or 2542 for <a href="showq.8.html">showq(8)</a> queue displays. </p> 2543 2544 2545 </DD> 2546 2547 <DT><b><a name="empty_address_recipient">empty_address_recipient</a> 2548 (default: MAILER-DAEMON)</b></DT><DD> 2549 2550 <p> 2551 The recipient of mail addressed to the null address. Postfix does 2552 not accept such addresses in SMTP commands, but they may still be 2553 created locally as the result of configuration or software error. 2554 </p> 2555 2556 2557 </DD> 2558 2559 <DT><b><a name="empty_address_relayhost_maps_lookup_key">empty_address_relayhost_maps_lookup_key</a> 2560 (default: <>)</b></DT><DD> 2561 2562 <p> The <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> search string that will be 2563 used instead of the null sender address. </p> 2564 2565 <p> This feature is available in Postfix 2.5 and later. With 2566 earlier versions, <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> lookups were 2567 skipped for the null sender address. </p> 2568 2569 2570 </DD> 2571 2572 <DT><b><a name="enable_errors_to">enable_errors_to</a> 2573 (default: no)</b></DT><DD> 2574 2575 <p> Report mail delivery errors to the address specified with the 2576 non-standard Errors-To: message header, instead of the envelope 2577 sender address (this feature is removed with Postfix version 2.2, is 2578 turned off by default with Postfix version 2.1, and is always turned on 2579 with older Postfix versions). </p> 2580 2581 2582 </DD> 2583 2584 <DT><b><a name="enable_original_recipient">enable_original_recipient</a> 2585 (default: yes)</b></DT><DD> 2586 2587 <p> Enable support for the X-Original-To message header. This header 2588 is needed for multi-recipient mailboxes. </p> 2589 2590 <p> When this parameter is set to yes, the <a href="cleanup.8.html">cleanup(8)</a> daemon performs 2591 duplicate elimination on distinct pairs of (original recipient, 2592 rewritten recipient), and generates non-empty original recipient 2593 queue file records. </p> 2594 2595 <p> When this parameter is set to no, the <a href="cleanup.8.html">cleanup(8)</a> daemon performs 2596 duplicate elimination on the rewritten recipient address only, and 2597 generates empty original recipient queue file records. </p> 2598 2599 <p> This feature is available in Postfix 2.1 and later. With Postfix 2600 version 2.0, support for the X-Original-To message header is always turned 2601 on. Postfix versions before 2.0 have no support for the X-Original-To 2602 message header. </p> 2603 2604 2605 </DD> 2606 2607 <DT><b><a name="error_notice_recipient">error_notice_recipient</a> 2608 (default: postmaster)</b></DT><DD> 2609 2610 <p> The recipient of postmaster notifications about mail delivery 2611 problems that are caused by policy, resource, software or protocol 2612 errors. These notifications are enabled with the <a href="postconf.5.html#notify_classes">notify_classes</a> 2613 parameter. </p> 2614 2615 2616 </DD> 2617 2618 <DT><b><a name="error_service_name">error_service_name</a> 2619 (default: error)</b></DT><DD> 2620 2621 <p> 2622 The name of the <a href="error.8.html">error(8)</a> pseudo delivery agent. This service always 2623 returns mail as undeliverable. 2624 </p> 2625 2626 <p> 2627 This feature is available in Postfix 2.0 and later. 2628 </p> 2629 2630 2631 </DD> 2632 2633 <DT><b><a name="execution_directory_expansion_filter">execution_directory_expansion_filter</a> 2634 (default: see "postconf -d" output)</b></DT><DD> 2635 2636 <p> Restrict the characters that the <a href="local.8.html">local(8)</a> delivery agent allows 2637 in $name expansions of $<a href="postconf.5.html#command_execution_directory">command_execution_directory</a>. Characters 2638 outside the allowed set are replaced by underscores. </p> 2639 2640 <p> This feature is available in Postfix 2.2 and later. </p> 2641 2642 2643 </DD> 2644 2645 <DT><b><a name="expand_owner_alias">expand_owner_alias</a> 2646 (default: no)</b></DT><DD> 2647 2648 <p> 2649 When delivering to an alias "aliasname" that has an "owner-aliasname" 2650 companion alias, set the envelope sender address to the expansion 2651 of the "owner-aliasname" alias. Normally, Postfix sets the envelope 2652 sender address to the name of the "owner-aliasname" alias. 2653 </p> 2654 2655 2656 </DD> 2657 2658 <DT><b><a name="export_environment">export_environment</a> 2659 (default: see "postconf -d" output)</b></DT><DD> 2660 2661 <p> 2662 The list of environment variables that a Postfix process will export 2663 to non-Postfix processes. The TZ variable is needed for sane 2664 time keeping on System-V-ish systems. 2665 </p> 2666 2667 <p> 2668 Specify a list of names and/or name=value pairs, separated by 2669 whitespace or comma. The name=value form is supported with 2670 Postfix version 2.1 and later. 2671 </p> 2672 2673 <p> 2674 Example: 2675 </p> 2676 2677 <pre> 2678 <a href="postconf.5.html#export_environment">export_environment</a> = TZ PATH=/bin:/usr/bin 2679 </pre> 2680 2681 2682 </DD> 2683 2684 <DT><b><a name="extract_recipient_limit">extract_recipient_limit</a> 2685 (default: 10240)</b></DT><DD> 2686 2687 <p> 2688 The maximal number of recipient addresses that Postfix will extract 2689 from message headers when mail is submitted with "<b>sendmail -t</b>". 2690 </p> 2691 2692 <p> 2693 This feature was removed in Postfix version 2.1. 2694 </p> 2695 2696 2697 </DD> 2698 2699 <DT><b><a name="fallback_relay">fallback_relay</a> 2700 (default: empty)</b></DT><DD> 2701 2702 <p> 2703 Optional list of relay hosts for SMTP destinations that can't be 2704 found or that are unreachable. With Postfix 2.3 this parameter 2705 is renamed to <a href="postconf.5.html#smtp_fallback_relay">smtp_fallback_relay</a>. </p> 2706 2707 <p> 2708 By default, mail is returned to the sender when a destination is 2709 not found, and delivery is deferred when a destination is unreachable. 2710 </p> 2711 2712 <p> The fallback relays must be SMTP destinations. Specify a domain, 2713 host, host:port, [host]:port, [address] or [address]:port; the form 2714 [host] turns off MX lookups. If you specify multiple SMTP 2715 destinations, Postfix will try them in the specified order. </p> 2716 2717 <p> Note: before Postfix 2.2, do not use the <a href="postconf.5.html#fallback_relay">fallback_relay</a> feature 2718 when relaying mail 2719 for a backup or primary MX domain. Mail would loop between the 2720 Postfix MX host and the <a href="postconf.5.html#fallback_relay">fallback_relay</a> host when the final destination 2721 is unavailable. </p> 2722 2723 <ul> 2724 2725 <li> In <a href="postconf.5.html">main.cf</a> specify "<a href="postconf.5.html#relay_transport">relay_transport</a> = relay", 2726 2727 <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 2728 the end of the <tt>relay</tt> entry. 2729 2730 <li> In transport maps, specify "relay:<i>nexthop...</i>" 2731 as the right-hand side for backup or primary MX domain entries. 2732 2733 </ul> 2734 2735 <p> Postfix version 2.2 and later will not use the <a href="postconf.5.html#fallback_relay">fallback_relay</a> feature 2736 for destinations that it is MX host for. 2737 </p> 2738 2739 2740 </DD> 2741 2742 <DT><b><a name="fallback_transport">fallback_transport</a> 2743 (default: empty)</b></DT><DD> 2744 2745 <p> 2746 Optional message delivery transport that the <a href="local.8.html">local(8)</a> delivery 2747 agent should use for names that are not found in the <a href="aliases.5.html">aliases(5)</a> 2748 or UNIX password database. 2749 </p> 2750 2751 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 2752 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>, 2753 <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>, 2754 <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> 2755 2756 2757 </DD> 2758 2759 <DT><b><a name="fallback_transport_maps">fallback_transport_maps</a> 2760 (default: empty)</b></DT><DD> 2761 2762 <p> Optional lookup tables with per-recipient message delivery 2763 transports for recipients that the <a href="local.8.html">local(8)</a> delivery agent could 2764 not find in the <a href="aliases.5.html">aliases(5)</a> or UNIX password database. </p> 2765 2766 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 2767 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>, 2768 <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>, 2769 <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> 2770 2771 <p> For safety reasons, this feature does not allow $number 2772 substitutions in regular expression maps. </p> 2773 2774 <p> This feature is available in Postfix 2.3 and later. </p> 2775 2776 2777 </DD> 2778 2779 <DT><b><a name="fast_flush_domains">fast_flush_domains</a> 2780 (default: $<a href="postconf.5.html#relay_domains">relay_domains</a>)</b></DT><DD> 2781 2782 <p> 2783 Optional list of destinations that are eligible for per-destination 2784 logfiles with mail that is queued to those destinations. 2785 </p> 2786 2787 <p> 2788 By default, Postfix maintains "fast flush" logfiles only for 2789 destinations that the Postfix SMTP server is willing to relay to 2790 (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 2791 the <a href="postconf.5.html#relay_domains">relay_domains</a> parameter in the <a href="postconf.5.html">postconf(5)</a> manual). 2792 </p> 2793 2794 <p> Specify a list of hosts or domains, "/file/name" patterns or 2795 "<a href="DATABASE_README.html">type:table</a>" lookup tables, separated by commas and/or whitespace. 2796 Continue long lines by starting the next line with whitespace. A 2797 "/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" 2798 lookup table is matched when the domain or its parent domain appears 2799 as lookup key. </p> 2800 2801 <p> 2802 Specify "<a href="postconf.5.html#fast_flush_domains">fast_flush_domains</a> =" (i.e., empty) to disable the feature 2803 altogether. 2804 </p> 2805 2806 2807 </DD> 2808 2809 <DT><b><a name="fast_flush_purge_time">fast_flush_purge_time</a> 2810 (default: 7d)</b></DT><DD> 2811 2812 <p> 2813 The time after which an empty per-destination "fast flush" logfile 2814 is deleted. 2815 </p> 2816 2817 <p> 2818 You can specify the time as a number, or as a number followed by 2819 a letter that indicates the time unit: s=seconds, m=minutes, h=hours, 2820 d=days, w=weeks. The default time unit is days. 2821 </p> 2822 2823 2824 </DD> 2825 2826 <DT><b><a name="fast_flush_refresh_time">fast_flush_refresh_time</a> 2827 (default: 12h)</b></DT><DD> 2828 2829 <p> 2830 The time after which a non-empty but unread per-destination "fast 2831 flush" logfile needs to be refreshed. The contents of a logfile 2832 are refreshed by requesting delivery of all messages listed in the 2833 logfile. 2834 </p> 2835 2836 <p> 2837 You can specify the time as a number, or as a number followed by 2838 a letter that indicates the time unit: s=seconds, m=minutes, h=hours, 2839 d=days, w=weeks. The default time unit is hours. 2840 </p> 2841 2842 2843 </DD> 2844 2845 <DT><b><a name="fault_injection_code">fault_injection_code</a> 2846 (default: 0)</b></DT><DD> 2847 2848 <p> 2849 Force specific internal tests to fail, to test the handling of 2850 errors that are difficult to reproduce otherwise. 2851 </p> 2852 2853 2854 </DD> 2855 2856 <DT><b><a name="flush_service_name">flush_service_name</a> 2857 (default: flush)</b></DT><DD> 2858 2859 <p> 2860 The name of the <a href="flush.8.html">flush(8)</a> service. This service maintains per-destination 2861 logfiles with the queue file names of mail that is queued for those 2862 destinations. 2863 </p> 2864 2865 <p> 2866 This feature is available in Postfix 2.0 and later. 2867 </p> 2868 2869 2870 </DD> 2871 2872 <DT><b><a name="fork_attempts">fork_attempts</a> 2873 (default: 5)</b></DT><DD> 2874 2875 <p> The maximal number of attempts to fork() a child process. </p> 2876 2877 2878 </DD> 2879 2880 <DT><b><a name="fork_delay">fork_delay</a> 2881 (default: 1s)</b></DT><DD> 2882 2883 <p> The delay between attempts to fork() a child process. </p> 2884 2885 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 2886 (weeks). The default time unit is s (seconds). </p> 2887 2888 2889 </DD> 2890 2891 <DT><b><a name="forward_expansion_filter">forward_expansion_filter</a> 2892 (default: see "postconf -d" output)</b></DT><DD> 2893 2894 <p> 2895 Restrict the characters that the <a href="local.8.html">local(8)</a> delivery agent allows in 2896 $name expansions of $<a href="postconf.5.html#forward_path">forward_path</a>. Characters outside the 2897 allowed set are replaced by underscores. 2898 </p> 2899 2900 2901 </DD> 2902 2903 <DT><b><a name="forward_path">forward_path</a> 2904 (default: see "postconf -d" output)</b></DT><DD> 2905 2906 <p> The <a href="local.8.html">local(8)</a> delivery agent search list for finding a .forward 2907 file with user-specified delivery methods. The first file that is 2908 found is used. </p> 2909 2910 <p> The following $name expansions are done on <a href="postconf.5.html#forward_path">forward_path</a> before 2911 the search actually happens. The result of $name expansion is 2912 filtered with the character set that is specified with the 2913 <a href="postconf.5.html#forward_expansion_filter">forward_expansion_filter</a> parameter. </p> 2914 2915 <dl> 2916 2917 <dt><b>$user</b></dt> 2918 2919 <dd>The recipient's username. </dd> 2920 2921 <dt><b>$shell</b></dt> 2922 2923 <dd>The recipient's login shell pathname. </dd> 2924 2925 <dt><b>$home</b></dt> 2926 2927 <dd>The recipient's home directory. </dd> 2928 2929 <dt><b>$recipient</b></dt> 2930 2931 <dd>The full recipient address. </dd> 2932 2933 <dt><b>$extension</b></dt> 2934 2935 <dd>The optional recipient address extension. </dd> 2936 2937 <dt><b>$domain</b></dt> 2938 2939 <dd>The recipient domain. </dd> 2940 2941 <dt><b>$local</b></dt> 2942 2943 <dd>The entire recipient localpart. </dd> 2944 2945 <dt><b>$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b></dt> 2946 2947 <dd>The system-wide recipient address extension delimiter. </dd> 2948 2949 <dt><b>${name?value}</b></dt> 2950 2951 <dd>Expands to <i>value</i> when <i>$name</i> is non-empty. </dd> 2952 2953 <dt><b>${name:value}</b></dt> 2954 2955 <dd>Expands to <i>value</i> when <i>$name</i> is empty. </dd> 2956 2957 </dl> 2958 2959 <p> 2960 Instead of $name you can also specify ${name} or $(name). 2961 </p> 2962 2963 <p> 2964 Examples: 2965 </p> 2966 2967 <pre> 2968 <a href="postconf.5.html#forward_path">forward_path</a> = /var/forward/$user 2969 <a href="postconf.5.html#forward_path">forward_path</a> = 2970 /var/forward/$user/.forward$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a>$extension, 2971 /var/forward/$user/.forward 2972 </pre> 2973 2974 2975 </DD> 2976 2977 <DT><b><a name="frozen_delivered_to">frozen_delivered_to</a> 2978 (default: yes)</b></DT><DD> 2979 2980 <p> Update the <a href="local.8.html">local(8)</a> delivery agent's idea of the Delivered-To: 2981 address (see <a href="postconf.5.html#prepend_delivered_header">prepend_delivered_header</a>) only once, at the start of 2982 a delivery attempt; do not update the Delivered-To: address while 2983 expanding aliases or .forward files. </p> 2984 2985 <p> This feature is available in Postfix 2.3 and later. With older 2986 Postfix releases, the behavior is as if this parameter is set to 2987 "no". The old setting can be expensive with deeply nested aliases 2988 or .forward files. When an alias or .forward file changes the 2989 Delivered-To: address, it ties up one queue file and one cleanup 2990 process instance while mail is being forwarded. </p> 2991 2992 2993 </DD> 2994 2995 <DT><b><a name="hash_queue_depth">hash_queue_depth</a> 2996 (default: 1)</b></DT><DD> 2997 2998 <p> 2999 The number of subdirectory levels for queue directories listed with 3000 the <a href="postconf.5.html#hash_queue_names">hash_queue_names</a> parameter. 3001 </p> 3002 3003 <p> 3004 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, 3005 execute the command "<b>postfix reload</b>". 3006 </p> 3007 3008 3009 </DD> 3010 3011 <DT><b><a name="hash_queue_names">hash_queue_names</a> 3012 (default: deferred, defer)</b></DT><DD> 3013 3014 <p> 3015 The names of queue directories that are split across multiple 3016 subdirectory levels. 3017 </p> 3018 3019 <p> Before Postfix version 2.2, the default list of hashed queues 3020 was significantly larger. Claims about improvements in file system 3021 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> 3022 is no longer needed. Fewer hashed directories speed up the time 3023 needed to restart Postfix. </p> 3024 3025 <p> 3026 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, 3027 execute the command "<b>postfix reload</b>". 3028 </p> 3029 3030 3031 </DD> 3032 3033 <DT><b><a name="header_address_token_limit">header_address_token_limit</a> 3034 (default: 10240)</b></DT><DD> 3035 3036 <p> 3037 The maximal number of address tokens are allowed in an address 3038 message header. Information that exceeds the limit is discarded. 3039 The limit is enforced by the <a href="cleanup.8.html">cleanup(8)</a> server. 3040 </p> 3041 3042 3043 </DD> 3044 3045 <DT><b><a name="header_checks">header_checks</a> 3046 (default: empty)</b></DT><DD> 3047 3048 <p> 3049 Optional lookup tables for content inspection of primary non-MIME 3050 message headers, as specified in the <a href="header_checks.5.html">header_checks(5)</a> manual page. 3051 </p> 3052 3053 3054 </DD> 3055 3056 <DT><b><a name="header_size_limit">header_size_limit</a> 3057 (default: 102400)</b></DT><DD> 3058 3059 <p> 3060 The maximal amount of memory in bytes for storing a message header. 3061 If a header is larger, the excess is discarded. The limit is 3062 enforced by the <a href="cleanup.8.html">cleanup(8)</a> server. 3063 </p> 3064 3065 3066 </DD> 3067 3068 <DT><b><a name="helpful_warnings">helpful_warnings</a> 3069 (default: yes)</b></DT><DD> 3070 3071 <p> 3072 Log warnings about problematic configuration settings, and provide 3073 helpful suggestions. 3074 </p> 3075 3076 <p> 3077 This feature is available in Postfix 2.0 and later. 3078 </p> 3079 3080 3081 </DD> 3082 3083 <DT><b><a name="home_mailbox">home_mailbox</a> 3084 (default: empty)</b></DT><DD> 3085 3086 <p> 3087 Optional pathname of a mailbox file relative to a <a href="local.8.html">local(8)</a> user's 3088 home directory. 3089 </p> 3090 3091 <p> 3092 Specify a pathname ending in "/" for qmail-style delivery. 3093 </p> 3094 3095 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 3096 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>, 3097 <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>, 3098 <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> 3099 3100 <p> 3101 Examples: 3102 </p> 3103 3104 <pre> 3105 <a href="postconf.5.html#home_mailbox">home_mailbox</a> = Mailbox 3106 <a href="postconf.5.html#home_mailbox">home_mailbox</a> = Maildir/ 3107 </pre> 3108 3109 3110 </DD> 3111 3112 <DT><b><a name="hopcount_limit">hopcount_limit</a> 3113 (default: 50)</b></DT><DD> 3114 3115 <p> 3116 The maximal number of Received: message headers that is allowed 3117 in the primary message headers. A message that exceeds the limit 3118 is bounced, in order to stop a mailer loop. 3119 </p> 3120 3121 3122 </DD> 3123 3124 <DT><b><a name="html_directory">html_directory</a> 3125 (default: see "postconf -d" output)</b></DT><DD> 3126 3127 <p> 3128 The location of Postfix HTML files that describe how to build, 3129 configure or operate a specific Postfix subsystem or feature. 3130 </p> 3131 3132 3133 </DD> 3134 3135 <DT><b><a name="ignore_mx_lookup_error">ignore_mx_lookup_error</a> 3136 (default: no)</b></DT><DD> 3137 3138 <p> Ignore DNS MX lookups that produce no response. By default, 3139 the Postfix SMTP client defers delivery and tries again after some 3140 delay. This behavior is required by the SMTP standard. </p> 3141 3142 <p> 3143 Specify "<a href="postconf.5.html#ignore_mx_lookup_error">ignore_mx_lookup_error</a> = yes" to force a DNS A record 3144 lookup instead. This violates the SMTP standard and can result in 3145 mis-delivery of mail. 3146 </p> 3147 3148 3149 </DD> 3150 3151 <DT><b><a name="import_environment">import_environment</a> 3152 (default: see "postconf -d" output)</b></DT><DD> 3153 3154 <p> 3155 The list of environment parameters that a Postfix process will 3156 import from a non-Postfix parent process. Examples of relevant 3157 parameters: 3158 </p> 3159 3160 <dl> 3161 3162 <dt><b>TZ</b></dt> 3163 3164 <dd>Needed for sane time keeping on most System-V-ish systems. </dd> 3165 3166 <dt><b>DISPLAY</b></dt> 3167 3168 <dd>Needed for debugging Postfix daemons with an X-windows debugger. </dd> 3169 3170 <dt><b>XAUTHORITY</b></dt> 3171 3172 <dd>Needed for debugging Postfix daemons with an X-windows debugger. </dd> 3173 3174 <dt><b>MAIL_CONFIG</b></dt> 3175 3176 <dd>Needed to make "<b>postfix -c</b>" work. </dd> 3177 3178 </dl> 3179 3180 <p> Specify a list of names and/or name=value pairs, separated by 3181 whitespace or comma. The name=value form is supported with 3182 Postfix version 2.1 and later. </p> 3183 3184 3185 </DD> 3186 3187 <DT><b><a name="in_flow_delay">in_flow_delay</a> 3188 (default: 1s)</b></DT><DD> 3189 3190 <p> Time to pause before accepting a new message, when the message 3191 arrival rate exceeds the message delivery rate. This feature is 3192 turned on by default (it's disabled on SCO UNIX due to an SCO bug). 3193 </p> 3194 3195 <p> 3196 With the default 100 SMTP server process limit, "<a href="postconf.5.html#in_flow_delay">in_flow_delay</a> 3197 = 1s" limits the mail inflow to 100 messages per second above the 3198 number of messages delivered per second. 3199 </p> 3200 3201 <p> 3202 Specify 0 to disable the feature. Valid delays are 0..10. 3203 </p> 3204 3205 3206 </DD> 3207 3208 <DT><b><a name="inet_interfaces">inet_interfaces</a> 3209 (default: all)</b></DT><DD> 3210 3211 <p> The network interface addresses that this mail system receives 3212 mail on. Specify "all" to receive mail on all network 3213 interfaces (default), and "loopback-only" to receive mail 3214 on loopback network interfaces only (Postfix version 2.2 and later). The 3215 parameter also controls delivery of mail to <tt>user@[ip.address]</tt>. 3216 </p> 3217 3218 <p> 3219 Note 1: you need to stop and start Postfix when this parameter changes. 3220 </p> 3221 3222 <p> Note 2: address information may be enclosed inside <tt>[]</tt>, 3223 but this form is not required here. </p> 3224 3225 <p> When <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> specifies just one IPv4 and/or IPv6 address 3226 that is not a loopback address, the Postfix SMTP client will use 3227 this address as the IP source address for outbound mail. Support 3228 for IPv6 is available in Postfix version 2.2 and later. </p> 3229 3230 <p> 3231 On a multi-homed firewall with separate Postfix instances listening on the 3232 "inside" and "outside" interfaces, this can prevent each instance from 3233 being able to reach servers on the "other side" of the firewall. Setting 3234 <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a> to 0.0.0.0 avoids the potential problem for 3235 IPv4, and setting <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a> to :: solves the problem 3236 for IPv6. </p> 3237 3238 <p> 3239 A better solution for multi-homed firewalls is to leave <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> 3240 at the default value and instead use explicit IP addresses in 3241 the <a href="master.5.html">master.cf</a> SMTP server definitions. This preserves the Postfix 3242 SMTP client's 3243 loop detection, by ensuring that each side of the firewall knows that the 3244 other IP address is still the same host. Setting $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> to a 3245 single IPv4 and/or IPV6 address is primarily useful with virtual 3246 hosting of domains on 3247 secondary IP addresses, when each IP address serves a different domain 3248 (and has a different $<a href="postconf.5.html#myhostname">myhostname</a> setting). </p> 3249 3250 <p> 3251 See also the <a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> parameter, for network addresses that 3252 are forwarded to Postfix by way of a proxy or address translator. 3253 </p> 3254 3255 <p> 3256 Examples: 3257 </p> 3258 3259 <pre> 3260 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = all (DEFAULT) 3261 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = loopback-only (Postfix version 2.2 and later) 3262 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = 127.0.0.1 3263 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = 127.0.0.1, [::1] (Postfix version 2.2 and later) 3264 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = 192.168.1.2, 127.0.0.1 3265 </pre> 3266 3267 3268 </DD> 3269 3270 <DT><b><a name="inet_protocols">inet_protocols</a> 3271 (default: ipv4)</b></DT><DD> 3272 3273 <p> The Internet protocols Postfix will attempt to use when making 3274 or accepting connections. Specify one or more of "ipv4" 3275 or "ipv6", separated by whitespace or commas. The form 3276 "all" is equivalent to "ipv4, ipv6" or "ipv4", depending 3277 on whether the operating system implements IPv6. </p> 3278 3279 <p> This feature is available in Postfix 2.2 and later. </p> 3280 3281 <p> Note: you MUST stop and start Postfix after changing this 3282 parameter. </p> 3283 3284 <p> On systems that pre-date IPV6_V6ONLY support (<a href="http://tools.ietf.org/html/rfc3493">RFC 3493</a>), an 3285 IPv6 server will also accept IPv4 connections, even when IPv4 is 3286 turned off with the <a href="postconf.5.html#inet_protocols">inet_protocols</a> parameter. On systems with 3287 IPV6_V6ONLY support, Postfix will use separate server sockets for 3288 IPv6 and IPv4, and each will accept only connections for the 3289 corresponding protocol. </p> 3290 3291 <p> When IPv4 support is enabled via the <a href="postconf.5.html#inet_protocols">inet_protocols</a> parameter, 3292 Postfix will to DNS type A record lookups, and will convert 3293 IPv4-in-IPv6 client IP addresses (::ffff:1.2.3.4) to their original 3294 IPv4 form (1.2.3.4). The latter is needed on hosts that pre-date 3295 IPV6_V6ONLY support (<a href="http://tools.ietf.org/html/rfc3493">RFC 3493</a>). </p> 3296 3297 <p> When IPv6 support is enabled via the <a href="postconf.5.html#inet_protocols">inet_protocols</a> parameter, 3298 Postfix will do DNS type AAAA record lookups. </p> 3299 3300 <p> When both IPv4 and IPv6 support are enabled, the Postfix SMTP 3301 client will attempt to connect via IPv6 before attempting to use 3302 IPv4. </p> 3303 3304 <p> 3305 Examples: 3306 </p> 3307 3308 <pre> 3309 <a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv4 (DEFAULT) 3310 <a href="postconf.5.html#inet_protocols">inet_protocols</a> = all 3311 <a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv6 3312 <a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv4, ipv6 3313 </pre> 3314 3315 3316 </DD> 3317 3318 <DT><b><a name="initial_destination_concurrency">initial_destination_concurrency</a> 3319 (default: 5)</b></DT><DD> 3320 3321 <p> 3322 The initial per-destination concurrency level for parallel delivery 3323 to the same destination. 3324 With per-destination recipient limit > 1, a destination is a domain, 3325 otherwise it is a recipient. 3326 </p> 3327 3328 <p> Use <a href="postconf.5.html#transport_initial_destination_concurrency"><i>transport</i>_initial_destination_concurrency</a> to specify 3329 a transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a> 3330 name of the message delivery transport (Postfix 2.5 and later). </p> 3331 3332 <p> 3333 Warning: with concurrency of 1, one bad message can be enough to 3334 block all mail to a site. 3335 </p> 3336 3337 3338 </DD> 3339 3340 <DT><b><a name="internal_mail_filter_classes">internal_mail_filter_classes</a> 3341 (default: empty)</b></DT><DD> 3342 3343 <p> What categories of Postfix-generated mail are subject to 3344 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> 3345 and <a href="postconf.5.html#body_checks">body_checks</a>. Specify zero or more of the following, separated 3346 by whitespace or comma. </p> 3347 3348 <dl> 3349 3350 <dt><b>bounce</b></dt> <dd> Inspect the content of delivery 3351 status notifications. </dd> 3352 3353 <dt><b>notify</b></dt> <dd> Inspect the content of postmaster 3354 notifications by the <a href="smtp.8.html">smtp(8)</a> and <a href="smtpd.8.html">smtpd(8)</a> processes. </dd> 3355 3356 </dl> 3357 3358 <p> NOTE: It's generally not safe to enable content inspection of 3359 Postfix-generated email messages. The user is warned. </p> 3360 3361 <p> This feature is available in Postfix 2.3 and later. </p> 3362 3363 3364 </DD> 3365 3366 <DT><b><a name="invalid_hostname_reject_code">invalid_hostname_reject_code</a> 3367 (default: 501)</b></DT><DD> 3368 3369 <p> 3370 The numerical Postfix SMTP server response code when the client 3371 HELO or EHLO command parameter is rejected by the <a href="postconf.5.html#reject_invalid_helo_hostname">reject_invalid_helo_hostname</a> 3372 restriction. 3373 </p> 3374 3375 <p> 3376 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 3377 </p> 3378 3379 3380 </DD> 3381 3382 <DT><b><a name="ipc_idle">ipc_idle</a> 3383 (default: version dependent)</b></DT><DD> 3384 3385 <p> 3386 The time after which a client closes an idle internal communication 3387 channel. The purpose is to allow servers to terminate voluntarily 3388 after they become idle. This is used, for example, by the address 3389 resolving and rewriting clients. 3390 </p> 3391 3392 <p> With Postfix 2.4 the default value was reduced from 100s to 5s. </p> 3393 3394 <p> 3395 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3396 The default time unit is s (seconds). 3397 </p> 3398 3399 3400 </DD> 3401 3402 <DT><b><a name="ipc_timeout">ipc_timeout</a> 3403 (default: 3600s)</b></DT><DD> 3404 3405 <p> 3406 The time limit for sending or receiving information over an internal 3407 communication channel. The purpose is to break out of deadlock 3408 situations. If the time limit is exceeded the software aborts with a 3409 fatal error. 3410 </p> 3411 3412 <p> 3413 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3414 The default time unit is s (seconds). 3415 </p> 3416 3417 3418 </DD> 3419 3420 <DT><b><a name="ipc_ttl">ipc_ttl</a> 3421 (default: 1000s)</b></DT><DD> 3422 3423 <p> 3424 The time after which a client closes an active internal communication 3425 channel. The purpose is to allow servers to terminate voluntarily 3426 after reaching their client limit. This is used, for example, by 3427 the address resolving and rewriting clients. 3428 </p> 3429 3430 <p> 3431 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3432 The default time unit is s (seconds). 3433 </p> 3434 3435 <p> 3436 This feature is available in Postfix 2.1 and later. 3437 </p> 3438 3439 3440 </DD> 3441 3442 <DT><b><a name="line_length_limit">line_length_limit</a> 3443 (default: 2048)</b></DT><DD> 3444 3445 <p> Upon input, long lines are chopped up into pieces of at most 3446 this length; upon delivery, long lines are reconstructed. </p> 3447 3448 3449 </DD> 3450 3451 <DT><b><a name="lmtp_assume_final">lmtp_assume_final</a> 3452 (default: no)</b></DT><DD> 3453 3454 <p> When an LMTP server announces no DSN support, assume that the 3455 server performs final delivery, and send "delivered" delivery status 3456 notifications instead of "relayed". The default setting is backwards 3457 compatible to avoid the infinetisimal possibility of breaking 3458 existing LMTP-based content filters. </p> 3459 3460 3461 </DD> 3462 3463 <DT><b><a name="lmtp_bind_address">lmtp_bind_address</a> 3464 (default: empty)</b></DT><DD> 3465 3466 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a> configuration 3467 parameter. See there for details. </p> 3468 3469 <p> This feature is available in Postfix 2.3 and later. </p> 3470 3471 3472 </DD> 3473 3474 <DT><b><a name="lmtp_bind_address6">lmtp_bind_address6</a> 3475 (default: empty)</b></DT><DD> 3476 3477 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a> configuration 3478 parameter. See there for details. </p> 3479 3480 <p> This feature is available in Postfix 2.3 and later. </p> 3481 3482 3483 </DD> 3484 3485 <DT><b><a name="lmtp_cache_connection">lmtp_cache_connection</a> 3486 (default: yes)</b></DT><DD> 3487 3488 <p> 3489 Keep Postfix LMTP client connections open for up to $<a href="postconf.5.html#max_idle">max_idle</a> 3490 seconds. When the LMTP client receives a request for the same 3491 connection the connection is reused. 3492 </p> 3493 3494 <p> This parameter is available in Postfix version 2.2 and earlier. 3495 With Postfix version 2.3 and later, see <a href="postconf.5.html#lmtp_connection_cache_on_demand">lmtp_connection_cache_on_demand</a>, 3496 <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>. 3497 </p> 3498 3499 <p> 3500 The effectiveness of cached connections will be determined by the 3501 number of LMTP servers in use, and the concurrency limit specified 3502 for the LMTP client. Cached connections are closed under any of 3503 the following conditions: 3504 </p> 3505 3506 <ul> 3507 3508 <li> The LMTP client idle time limit is reached. This limit is 3509 specified with the Postfix <a href="postconf.5.html#max_idle">max_idle</a> configuration parameter. 3510 3511 <li> A delivery request specifies a different destination than the 3512 one currently cached. 3513 3514 <li> The per-process limit on the number of delivery requests is 3515 reached. This limit is specified with the Postfix <a href="postconf.5.html#max_use">max_use</a> 3516 configuration parameter. 3517 3518 <li> Upon the onset of another delivery request, the LMTP server 3519 associated with the current session does not respond to the RSET 3520 command. 3521 3522 </ul> 3523 3524 <p> 3525 Most of these limitations will be removed after Postfix implements 3526 a connection cache that is shared among multiple LMTP client 3527 programs. 3528 </p> 3529 3530 3531 </DD> 3532 3533 <DT><b><a name="lmtp_cname_overrides_servername">lmtp_cname_overrides_servername</a> 3534 (default: yes)</b></DT><DD> 3535 3536 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_cname_overrides_servername">smtp_cname_overrides_servername</a> 3537 configuration parameter. See there for details. </p> 3538 3539 <p> This feature is available in Postfix 2.3 and later. </p> 3540 3541 3542 </DD> 3543 3544 <DT><b><a name="lmtp_connect_timeout">lmtp_connect_timeout</a> 3545 (default: 0s)</b></DT><DD> 3546 3547 <p> The LMTP client time limit for completing a TCP connection, or 3548 zero (use the operating system built-in time limit). When no 3549 connection can be made within the deadline, the LMTP client tries 3550 the next address on the mail exchanger list. </p> 3551 3552 <p> 3553 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3554 The default time unit is s (seconds). 3555 </p> 3556 3557 <p> 3558 Example: 3559 </p> 3560 3561 <pre> 3562 <a href="postconf.5.html#lmtp_connect_timeout">lmtp_connect_timeout</a> = 30s 3563 </pre> 3564 3565 3566 </DD> 3567 3568 <DT><b><a name="lmtp_connection_cache_destinations">lmtp_connection_cache_destinations</a> 3569 (default: empty)</b></DT><DD> 3570 3571 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_cache_destinations">smtp_connection_cache_destinations</a> 3572 configuration parameter. See there for details. </p> 3573 3574 <p> This feature is available in Postfix 2.3 and later. </p> 3575 3576 3577 </DD> 3578 3579 <DT><b><a name="lmtp_connection_cache_on_demand">lmtp_connection_cache_on_demand</a> 3580 (default: yes)</b></DT><DD> 3581 3582 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_cache_on_demand">smtp_connection_cache_on_demand</a> 3583 configuration parameter. See there for details. </p> 3584 3585 <p> This feature is available in Postfix 2.3 and later. </p> 3586 3587 3588 </DD> 3589 3590 <DT><b><a name="lmtp_connection_cache_time_limit">lmtp_connection_cache_time_limit</a> 3591 (default: 2s)</b></DT><DD> 3592 3593 <p> The LMTP-specific version of the 3594 <a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> configuration parameter. 3595 See there for details. </p> 3596 3597 <p> This feature is available in Postfix 2.3 and later. </p> 3598 3599 3600 </DD> 3601 3602 <DT><b><a name="lmtp_connection_reuse_time_limit">lmtp_connection_reuse_time_limit</a> 3603 (default: 300s)</b></DT><DD> 3604 3605 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a> 3606 configuration parameter. See there for details. </p> 3607 3608 <p> This feature is available in Postfix 2.3 and later. </p> 3609 3610 3611 </DD> 3612 3613 <DT><b><a name="lmtp_data_done_timeout">lmtp_data_done_timeout</a> 3614 (default: 600s)</b></DT><DD> 3615 3616 <p> The LMTP client time limit for sending the LMTP ".", and for 3617 receiving the server response. When no response is received within 3618 the deadline, a warning is logged that the mail may be delivered 3619 multiple times. </p> 3620 3621 <p> 3622 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3623 The default time unit is s (seconds). 3624 </p> 3625 3626 3627 </DD> 3628 3629 <DT><b><a name="lmtp_data_init_timeout">lmtp_data_init_timeout</a> 3630 (default: 120s)</b></DT><DD> 3631 3632 <p> 3633 The LMTP client time limit for sending the LMTP DATA command, and 3634 for receiving the server response. 3635 </p> 3636 3637 <p> 3638 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3639 The default time unit is s (seconds). 3640 </p> 3641 3642 3643 </DD> 3644 3645 <DT><b><a name="lmtp_data_xfer_timeout">lmtp_data_xfer_timeout</a> 3646 (default: 180s)</b></DT><DD> 3647 3648 <p> 3649 The LMTP client time limit for sending the LMTP message content. 3650 When the connection stalls for more than $<a href="postconf.5.html#lmtp_data_xfer_timeout">lmtp_data_xfer_timeout</a> 3651 the LMTP client terminates the transfer. 3652 </p> 3653 3654 <p> 3655 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3656 The default time unit is s (seconds). 3657 </p> 3658 3659 3660 </DD> 3661 3662 <DT><b><a name="lmtp_defer_if_no_mx_address_found">lmtp_defer_if_no_mx_address_found</a> 3663 (default: no)</b></DT><DD> 3664 3665 <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> 3666 configuration parameter. See there for details. </p> 3667 3668 <p> This feature is available in Postfix 2.3 and later. </p> 3669 3670 3671 </DD> 3672 3673 <DT><b><a name="lmtp_destination_concurrency_limit">lmtp_destination_concurrency_limit</a> 3674 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 3675 3676 <p> The maximal number of parallel deliveries to the same destination 3677 via the lmtp message delivery transport. This limit is enforced by 3678 the queue manager. The message delivery transport name is the first 3679 field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 3680 3681 3682 </DD> 3683 3684 <DT><b><a name="lmtp_destination_recipient_limit">lmtp_destination_recipient_limit</a> 3685 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 3686 3687 <p> The maximal number of recipients per message for the lmtp 3688 message delivery transport. This limit is enforced by the queue 3689 manager. The message delivery transport name is the first field in 3690 the entry in the <a href="master.5.html">master.cf</a> file. </p> 3691 3692 <p> Setting this parameter to a value of 1 changes the meaning of 3693 <a href="postconf.5.html#lmtp_destination_concurrency_limit">lmtp_destination_concurrency_limit</a> from concurrency per domain into 3694 concurrency per recipient. </p> 3695 3696 3697 </DD> 3698 3699 <DT><b><a name="lmtp_discard_lhlo_keyword_address_maps">lmtp_discard_lhlo_keyword_address_maps</a> 3700 (default: empty)</b></DT><DD> 3701 3702 <p> Lookup tables, indexed by the remote LMTP server address, with 3703 case insensitive lists of LHLO keywords (pipelining, starttls, 3704 auth, etc.) that the LMTP client will ignore in the LHLO response 3705 from a remote LMTP server. See <a href="postconf.5.html#lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a> for 3706 details. The table is not indexed by hostname for consistency with 3707 <a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a>. </p> 3708 3709 <p> This feature is available in Postfix 2.3 and later. </p> 3710 3711 3712 </DD> 3713 3714 <DT><b><a name="lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a> 3715 (default: empty)</b></DT><DD> 3716 3717 <p> A case insensitive list of LHLO keywords (pipelining, starttls, 3718 auth, etc.) that the LMTP client will ignore in the LHLO response 3719 from a remote LMTP server. </p> 3720 3721 <p> This feature is available in Postfix 2.3 and later. </p> 3722 3723 <p> Notes: </p> 3724 3725 <ul> 3726 3727 <li> <p> Specify the <b>silent-discard</b> pseudo keyword to prevent 3728 this action from being logged. </p> 3729 3730 <li> <p> Use the <a href="postconf.5.html#lmtp_discard_lhlo_keyword_address_maps">lmtp_discard_lhlo_keyword_address_maps</a> feature to 3731 discard LHLO keywords selectively. </p> 3732 3733 </ul> 3734 3735 3736 </DD> 3737 3738 <DT><b><a name="lmtp_enforce_tls">lmtp_enforce_tls</a> 3739 (default: no)</b></DT><DD> 3740 3741 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a> configuration 3742 parameter. See there for details. </p> 3743 3744 <p> This feature is available in Postfix 2.3 and later. </p> 3745 3746 3747 </DD> 3748 3749 <DT><b><a name="lmtp_generic_maps">lmtp_generic_maps</a> 3750 (default: empty)</b></DT><DD> 3751 3752 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_generic_maps">smtp_generic_maps</a> configuration 3753 parameter. See there for details. </p> 3754 3755 <p> This feature is available in Postfix 2.3 and later. </p> 3756 3757 3758 </DD> 3759 3760 <DT><b><a name="lmtp_host_lookup">lmtp_host_lookup</a> 3761 (default: dns)</b></DT><DD> 3762 3763 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_host_lookup">smtp_host_lookup</a> configuration 3764 parameter. See there for details. </p> 3765 3766 <p> This feature is available in Postfix 2.3 and later. </p> 3767 3768 3769 </DD> 3770 3771 <DT><b><a name="lmtp_lhlo_name">lmtp_lhlo_name</a> 3772 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 3773 3774 <p> 3775 The hostname to send in the LMTP LHLO command. 3776 </p> 3777 3778 <p> 3779 The default value is the machine hostname. Specify a hostname or 3780 [ip.add.re.ss]. 3781 </p> 3782 3783 <p> 3784 This information can be specified in the <a href="postconf.5.html">main.cf</a> file for all LMTP 3785 clients, or it can be specified in the <a href="master.5.html">master.cf</a> file for a specific 3786 client, for example: 3787 </p> 3788 3789 <blockquote> 3790 <pre> 3791 /etc/postfix/<a href="master.5.html">master.cf</a>: 3792 mylmtp ... lmtp -o <a href="postconf.5.html#lmtp_lhlo_name">lmtp_lhlo_name</a>=foo.bar.com 3793 </pre> 3794 </blockquote> 3795 3796 <p> 3797 This feature is available in Postfix 2.3 and later. 3798 </p> 3799 3800 3801 </DD> 3802 3803 <DT><b><a name="lmtp_lhlo_timeout">lmtp_lhlo_timeout</a> 3804 (default: 300s)</b></DT><DD> 3805 3806 <p> The LMTP client time limit for sending the LHLO command, and 3807 for receiving the initial server response. </p> 3808 3809 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 3810 (weeks). The default time unit is s (seconds). </p> 3811 3812 3813 </DD> 3814 3815 <DT><b><a name="lmtp_line_length_limit">lmtp_line_length_limit</a> 3816 (default: 990)</b></DT><DD> 3817 3818 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_line_length_limit">smtp_line_length_limit</a> 3819 configuration parameter. See there for details. </p> 3820 3821 <p> This feature is available in Postfix 2.3 and later. </p> 3822 3823 3824 </DD> 3825 3826 <DT><b><a name="lmtp_mail_timeout">lmtp_mail_timeout</a> 3827 (default: 300s)</b></DT><DD> 3828 3829 <p> 3830 The LMTP client time limit for sending the MAIL FROM command, and 3831 for receiving the server response. 3832 </p> 3833 3834 <p> 3835 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3836 The default time unit is s (seconds). 3837 </p> 3838 3839 3840 </DD> 3841 3842 <DT><b><a name="lmtp_mx_address_limit">lmtp_mx_address_limit</a> 3843 (default: 5)</b></DT><DD> 3844 3845 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_mx_address_limit">smtp_mx_address_limit</a> configuration 3846 parameter. See there for details. </p> 3847 3848 <p> This feature is available in Postfix 2.3 and later. </p> 3849 3850 3851 </DD> 3852 3853 <DT><b><a name="lmtp_mx_session_limit">lmtp_mx_session_limit</a> 3854 (default: 2)</b></DT><DD> 3855 3856 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_mx_session_limit">smtp_mx_session_limit</a> configuration 3857 parameter. See there for details. </p> 3858 3859 <p> This feature is available in Postfix 2.3 and later. </p> 3860 3861 3862 </DD> 3863 3864 <DT><b><a name="lmtp_pix_workaround_delay_time">lmtp_pix_workaround_delay_time</a> 3865 (default: 10s)</b></DT><DD> 3866 3867 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a> 3868 configuration parameter. See there for details. </p> 3869 3870 <p> This feature is available in Postfix 2.3 and later. </p> 3871 3872 3873 </DD> 3874 3875 <DT><b><a name="lmtp_pix_workaround_maps">lmtp_pix_workaround_maps</a> 3876 (default: empty)</b></DT><DD> 3877 3878 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_pix_workaround_maps">smtp_pix_workaround_maps</a> 3879 configuration parameter. See there for details. </p> 3880 3881 <p> This feature is available in Postfix 2.4 and later. </p> 3882 3883 3884 </DD> 3885 3886 <DT><b><a name="lmtp_pix_workaround_threshold_time">lmtp_pix_workaround_threshold_time</a> 3887 (default: 500s)</b></DT><DD> 3888 3889 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a> 3890 configuration parameter. See there for details. </p> 3891 3892 <p> This feature is available in Postfix 2.3 and later. </p> 3893 3894 3895 </DD> 3896 3897 <DT><b><a name="lmtp_pix_workarounds">lmtp_pix_workarounds</a> 3898 (default: empty)</b></DT><DD> 3899 3900 <p> The LMTP-specific version of the smtp_pix_workaround 3901 configuration parameter. See there for details. </p> 3902 3903 <p> This feature is available in Postfix 2.4 and later. </p> 3904 3905 3906 </DD> 3907 3908 <DT><b><a name="lmtp_quit_timeout">lmtp_quit_timeout</a> 3909 (default: 300s)</b></DT><DD> 3910 3911 <p> 3912 The LMTP client time limit for sending the QUIT command, and for 3913 receiving the server response. 3914 </p> 3915 3916 <p> 3917 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3918 The default time unit is s (seconds). 3919 </p> 3920 3921 3922 </DD> 3923 3924 <DT><b><a name="lmtp_quote_rfc821_envelope">lmtp_quote_rfc821_envelope</a> 3925 (default: yes)</b></DT><DD> 3926 3927 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a> 3928 configuration parameter. See there for details. </p> 3929 3930 <p> This feature is available in Postfix 2.3 and later. </p> 3931 3932 3933 </DD> 3934 3935 <DT><b><a name="lmtp_randomize_addresses">lmtp_randomize_addresses</a> 3936 (default: yes)</b></DT><DD> 3937 3938 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_randomize_addresses">smtp_randomize_addresses</a> 3939 configuration parameter. See there for details. </p> 3940 3941 <p> This feature is available in Postfix 2.3 and later. </p> 3942 3943 3944 </DD> 3945 3946 <DT><b><a name="lmtp_rcpt_timeout">lmtp_rcpt_timeout</a> 3947 (default: 300s)</b></DT><DD> 3948 3949 <p> 3950 The LMTP client time limit for sending the RCPT TO command, and 3951 for receiving the server response. 3952 </p> 3953 3954 <p> 3955 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3956 The default time unit is s (seconds). 3957 </p> 3958 3959 3960 </DD> 3961 3962 <DT><b><a name="lmtp_rset_timeout">lmtp_rset_timeout</a> 3963 (default: 20s)</b></DT><DD> 3964 3965 <p> The LMTP client time limit for sending the RSET command, and 3966 for receiving the server response. The LMTP client sends RSET in 3967 order to finish a recipient address probe, or to verify that a 3968 cached connection is still alive. </p> 3969 3970 <p> 3971 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 3972 The default time unit is s (seconds). 3973 </p> 3974 3975 3976 </DD> 3977 3978 <DT><b><a name="lmtp_sasl_auth_cache_name">lmtp_sasl_auth_cache_name</a> 3979 (default: empty)</b></DT><DD> 3980 3981 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> 3982 configuration parameter. See there for details. </p> 3983 3984 <p> This feature is available in Postfix 2.5 and later. </p> 3985 3986 3987 </DD> 3988 3989 <DT><b><a name="lmtp_sasl_auth_cache_time">lmtp_sasl_auth_cache_time</a> 3990 (default: 90d)</b></DT><DD> 3991 3992 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_auth_cache_time">smtp_sasl_auth_cache_time</a> 3993 configuration parameter. See there for details. </p> 3994 3995 <p> This feature is available in Postfix 2.5 and later. </p> 3996 3997 3998 </DD> 3999 4000 <DT><b><a name="lmtp_sasl_auth_enable">lmtp_sasl_auth_enable</a> 4001 (default: no)</b></DT><DD> 4002 4003 <p> 4004 Enable SASL authentication in the Postfix LMTP client. 4005 </p> 4006 4007 4008 </DD> 4009 4010 <DT><b><a name="lmtp_sasl_auth_soft_bounce">lmtp_sasl_auth_soft_bounce</a> 4011 (default: yes)</b></DT><DD> 4012 4013 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> 4014 configuration parameter. See there for details. </p> 4015 4016 <p> This feature is available in Postfix 2.5 and later. </p> 4017 4018 4019 </DD> 4020 4021 <DT><b><a name="lmtp_sasl_mechanism_filter">lmtp_sasl_mechanism_filter</a> 4022 (default: empty)</b></DT><DD> 4023 4024 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> 4025 configuration parameter. See there for details. </p> 4026 4027 <p> This feature is available in Postfix 2.3 and later. </p> 4028 4029 4030 </DD> 4031 4032 <DT><b><a name="lmtp_sasl_password_maps">lmtp_sasl_password_maps</a> 4033 (default: empty)</b></DT><DD> 4034 4035 <p> 4036 Optional LMTP client lookup tables with one username:password entry 4037 per host or domain. If a remote host or domain has no username:password 4038 entry, then the Postfix LMTP client will not attempt to authenticate 4039 to the remote host. 4040 </p> 4041 4042 4043 </DD> 4044 4045 <DT><b><a name="lmtp_sasl_path">lmtp_sasl_path</a> 4046 (default: empty)</b></DT><DD> 4047 4048 <p> Implementation-specific information that is passed through to 4049 the SASL plug-in implementation that is selected with 4050 <b><a href="postconf.5.html#lmtp_sasl_type">lmtp_sasl_type</a></b>. Typically this specifies the name of a 4051 configuration file or rendezvous point. </p> 4052 4053 <p> This feature is available in Postfix 2.3 and later. </p> 4054 4055 4056 </DD> 4057 4058 <DT><b><a name="lmtp_sasl_security_options">lmtp_sasl_security_options</a> 4059 (default: noplaintext, noanonymous)</b></DT><DD> 4060 4061 <p> SASL security options; as of Postfix 2.3 the list of available 4062 features depends on the SASL client implementation that is selected 4063 with <b><a href="postconf.5.html#lmtp_sasl_type">lmtp_sasl_type</a></b>. </p> 4064 4065 <p> The following security features are defined for the <b>cyrus</b> 4066 client SASL implementation: </p> 4067 4068 <dl> 4069 4070 <dt><b>noplaintext</b></dt> 4071 4072 <dd>Disallow authentication methods that use plaintext passwords. </dd> 4073 4074 <dt><b>noactive</b></dt> 4075 4076 <dd>Disallow authentication methods that are vulnerable to non-dictionary 4077 active attacks. </dd> 4078 4079 <dt><b>nodictionary</b></dt> 4080 4081 <dd>Disallow authentication methods that are vulnerable to passive 4082 dictionary attack. </dd> 4083 4084 <dt><b>noanonymous</b></dt> 4085 4086 <dd>Disallow anonymous logins. </dd> 4087 4088 </dl> 4089 4090 <p> 4091 Example: 4092 </p> 4093 4094 <pre> 4095 <a href="postconf.5.html#lmtp_sasl_security_options">lmtp_sasl_security_options</a> = noplaintext 4096 </pre> 4097 4098 4099 </DD> 4100 4101 <DT><b><a name="lmtp_sasl_tls_security_options">lmtp_sasl_tls_security_options</a> 4102 (default: $<a href="postconf.5.html#lmtp_sasl_security_options">lmtp_sasl_security_options</a>)</b></DT><DD> 4103 4104 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a> 4105 configuration parameter. See there for details. </p> 4106 4107 <p> This feature is available in Postfix 2.3 and later. </p> 4108 4109 4110 </DD> 4111 4112 <DT><b><a name="lmtp_sasl_tls_verified_security_options">lmtp_sasl_tls_verified_security_options</a> 4113 (default: $<a href="postconf.5.html#lmtp_sasl_tls_security_options">lmtp_sasl_tls_security_options</a>)</b></DT><DD> 4114 4115 <p> The LMTP-specific version of the 4116 <a href="postconf.5.html#smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a> configuration parameter. 4117 See there for details. </p> 4118 4119 <p> This feature is available in Postfix 2.3 and later. </p> 4120 4121 4122 </DD> 4123 4124 <DT><b><a name="lmtp_sasl_type">lmtp_sasl_type</a> 4125 (default: cyrus)</b></DT><DD> 4126 4127 <p> The SASL plug-in type that the Postfix LMTP client should use 4128 for authentication. The available types are listed with the 4129 "<b>postconf -A</b>" command. </p> 4130 4131 <p> This feature is available in Postfix 2.3 and later. </p> 4132 4133 4134 </DD> 4135 4136 <DT><b><a name="lmtp_send_xforward_command">lmtp_send_xforward_command</a> 4137 (default: no)</b></DT><DD> 4138 4139 <p> 4140 Send an XFORWARD command to the LMTP server when the LMTP LHLO 4141 server response announces XFORWARD support. This allows an <a href="lmtp.8.html">lmtp(8)</a> 4142 delivery agent, used for content filter message injection, to 4143 forward the name, address, protocol and HELO name of the original 4144 client to the content filter and downstream queuing LMTP server. 4145 Before you change the value to yes, it is best to make sure that 4146 your content filter supports this command. 4147 </p> 4148 4149 <p> 4150 This feature is available in Postfix 2.1 and later. 4151 </p> 4152 4153 4154 </DD> 4155 4156 <DT><b><a name="lmtp_sender_dependent_authentication">lmtp_sender_dependent_authentication</a> 4157 (default: no)</b></DT><DD> 4158 4159 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sender_dependent_authentication">smtp_sender_dependent_authentication</a> 4160 configuration parameter. See there for details. </p> 4161 4162 <p> This feature is available in Postfix 2.3 and later. </p> 4163 4164 4165 </DD> 4166 4167 <DT><b><a name="lmtp_skip_5xx_greeting">lmtp_skip_5xx_greeting</a> 4168 (default: yes)</b></DT><DD> 4169 4170 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_skip_5xx_greeting">smtp_skip_5xx_greeting</a> 4171 configuration parameter. See there for details. </p> 4172 4173 <p> This feature is available in Postfix 2.3 and later. </p> 4174 4175 4176 </DD> 4177 4178 <DT><b><a name="lmtp_skip_quit_response">lmtp_skip_quit_response</a> 4179 (default: no)</b></DT><DD> 4180 4181 <p> 4182 Wait for the response to the LMTP QUIT command. 4183 </p> 4184 4185 4186 </DD> 4187 4188 <DT><b><a name="lmtp_starttls_timeout">lmtp_starttls_timeout</a> 4189 (default: 300s)</b></DT><DD> 4190 4191 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_starttls_timeout">smtp_starttls_timeout</a> configuration 4192 parameter. See there for details. </p> 4193 4194 <p> This feature is available in Postfix 2.3 and later. </p> 4195 4196 4197 </DD> 4198 4199 <DT><b><a name="lmtp_tcp_port">lmtp_tcp_port</a> 4200 (default: 24)</b></DT><DD> 4201 4202 <p> 4203 The default TCP port that the Postfix LMTP client connects to. 4204 </p> 4205 4206 4207 </DD> 4208 4209 <DT><b><a name="lmtp_tls_CAfile">lmtp_tls_CAfile</a> 4210 (default: empty)</b></DT><DD> 4211 4212 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a> 4213 configuration parameter. See there for details. </p> 4214 4215 <p> This feature is available in Postfix 2.3 and later. </p> 4216 4217 4218 </DD> 4219 4220 <DT><b><a name="lmtp_tls_CApath">lmtp_tls_CApath</a> 4221 (default: empty)</b></DT><DD> 4222 4223 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a> 4224 configuration parameter. See there for details. </p> 4225 4226 <p> This feature is available in Postfix 2.3 and later. </p> 4227 4228 4229 </DD> 4230 4231 <DT><b><a name="lmtp_tls_cert_file">lmtp_tls_cert_file</a> 4232 (default: empty)</b></DT><DD> 4233 4234 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> 4235 configuration parameter. See there for details. </p> 4236 4237 <p> This feature is available in Postfix 2.3 and later. </p> 4238 4239 4240 </DD> 4241 4242 <DT><b><a name="lmtp_tls_ciphers">lmtp_tls_ciphers</a> 4243 (default: export)</b></DT><DD> 4244 4245 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> configuration 4246 parameter. See there for details. </p> 4247 4248 <p> This feature is available in Postfix 2.6 and later. </p> 4249 4250 4251 </DD> 4252 4253 <DT><b><a name="lmtp_tls_dcert_file">lmtp_tls_dcert_file</a> 4254 (default: empty)</b></DT><DD> 4255 4256 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> 4257 configuration parameter. See there for details. </p> 4258 4259 <p> This feature is available in Postfix 2.3 and later. </p> 4260 4261 4262 </DD> 4263 4264 <DT><b><a name="lmtp_tls_dkey_file">lmtp_tls_dkey_file</a> 4265 (default: $<a href="postconf.5.html#lmtp_tls_dcert_file">lmtp_tls_dcert_file</a>)</b></DT><DD> 4266 4267 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_dkey_file">smtp_tls_dkey_file</a> 4268 configuration parameter. See there for details. </p> 4269 4270 <p> This feature is available in Postfix 2.3 and later. </p> 4271 4272 4273 </DD> 4274 4275 <DT><b><a name="lmtp_tls_eccert_file">lmtp_tls_eccert_file</a> 4276 (default: empty)</b></DT><DD> 4277 4278 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a> configuration 4279 parameter. See there for details. </p> 4280 4281 <p> This feature is available in Postfix 2.6 and later, when Postfix is 4282 compiled and linked with OpenSSL 0.9.9 or later. </p> 4283 4284 4285 </DD> 4286 4287 <DT><b><a name="lmtp_tls_eckey_file">lmtp_tls_eckey_file</a> 4288 (default: empty)</b></DT><DD> 4289 4290 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_eckey_file">smtp_tls_eckey_file</a> configuration 4291 parameter. See there for details. </p> 4292 4293 <p> This feature is available in Postfix 2.6 and later, when Postfix is 4294 compiled and linked with OpenSSL 0.9.9 or later. </p> 4295 4296 4297 </DD> 4298 4299 <DT><b><a name="lmtp_tls_enforce_peername">lmtp_tls_enforce_peername</a> 4300 (default: yes)</b></DT><DD> 4301 4302 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> 4303 configuration parameter. 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_tls_exclude_ciphers">lmtp_tls_exclude_ciphers</a> 4311 (default: empty)</b></DT><DD> 4312 4313 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> 4314 configuration parameter. See there for details. </p> 4315 4316 <p> This feature is available in Postfix 2.3 and later. </p> 4317 4318 4319 </DD> 4320 4321 <DT><b><a name="lmtp_tls_fingerprint_cert_match">lmtp_tls_fingerprint_cert_match</a> 4322 (default: empty)</b></DT><DD> 4323 4324 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> 4325 configuration parameter. See there for details. </p> 4326 4327 <p> This feature is available in Postfix 2.5 and later. </p> 4328 4329 4330 </DD> 4331 4332 <DT><b><a name="lmtp_tls_fingerprint_digest">lmtp_tls_fingerprint_digest</a> 4333 (default: md5)</b></DT><DD> 4334 4335 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> 4336 configuration parameter. See there for details. </p> 4337 4338 <p> This feature is available in Postfix 2.5 and later. </p> 4339 4340 4341 </DD> 4342 4343 <DT><b><a name="lmtp_tls_key_file">lmtp_tls_key_file</a> 4344 (default: $<a href="postconf.5.html#lmtp_tls_cert_file">lmtp_tls_cert_file</a>)</b></DT><DD> 4345 4346 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a> 4347 configuration parameter. See there for details. </p> 4348 4349 <p> This feature is available in Postfix 2.3 and later. </p> 4350 4351 4352 </DD> 4353 4354 <DT><b><a name="lmtp_tls_loglevel">lmtp_tls_loglevel</a> 4355 (default: 0)</b></DT><DD> 4356 4357 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_loglevel">smtp_tls_loglevel</a> 4358 configuration parameter. See there for details. </p> 4359 4360 <p> This feature is available in Postfix 2.3 and later. </p> 4361 4362 4363 </DD> 4364 4365 <DT><b><a name="lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a> 4366 (default: empty)</b></DT><DD> 4367 4368 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> 4369 configuration parameter. See there for details. </p> 4370 4371 <p> This feature is available in Postfix 2.3 and later. </p> 4372 4373 4374 </DD> 4375 4376 <DT><b><a name="lmtp_tls_mandatory_exclude_ciphers">lmtp_tls_mandatory_exclude_ciphers</a> 4377 (default: empty)</b></DT><DD> 4378 4379 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> 4380 configuration parameter. See there for details. </p> 4381 4382 <p> This feature is available in Postfix 2.3 and later. </p> 4383 4384 4385 </DD> 4386 4387 <DT><b><a name="lmtp_tls_mandatory_protocols">lmtp_tls_mandatory_protocols</a> 4388 (default: SSLv3, TLSv1)</b></DT><DD> 4389 4390 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> 4391 configuration parameter. See there for details. </p> 4392 4393 <p> This feature is available in Postfix 2.3 and later. </p> 4394 4395 4396 </DD> 4397 4398 <DT><b><a name="lmtp_tls_note_starttls_offer">lmtp_tls_note_starttls_offer</a> 4399 (default: no)</b></DT><DD> 4400 4401 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_note_starttls_offer">smtp_tls_note_starttls_offer</a> 4402 configuration parameter. See there for details. </p> 4403 4404 <p> This feature is available in Postfix 2.3 and later. </p> 4405 4406 4407 </DD> 4408 4409 <DT><b><a name="lmtp_tls_per_site">lmtp_tls_per_site</a> 4410 (default: empty)</b></DT><DD> 4411 4412 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> configuration 4413 parameter. See there for details. </p> 4414 4415 <p> This feature is available in Postfix 2.3 and later. </p> 4416 4417 4418 </DD> 4419 4420 <DT><b><a name="lmtp_tls_policy_maps">lmtp_tls_policy_maps</a> 4421 (default: empty)</b></DT><DD> 4422 4423 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> 4424 configuration parameter. See there for details. </p> 4425 4426 <p> This feature is available in Postfix 2.3 and later. </p> 4427 4428 4429 </DD> 4430 4431 <DT><b><a name="lmtp_tls_protocols">lmtp_tls_protocols</a> 4432 (default: empty)</b></DT><DD> 4433 4434 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> configuration 4435 parameter. See there for details. </p> 4436 4437 <p> This feature is available in Postfix 2.6 and later. </p> 4438 4439 4440 </DD> 4441 4442 <DT><b><a name="lmtp_tls_scert_verifydepth">lmtp_tls_scert_verifydepth</a> 4443 (default: 9)</b></DT><DD> 4444 4445 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_scert_verifydepth">smtp_tls_scert_verifydepth</a> 4446 configuration parameter. See there for details. </p> 4447 4448 <p> This feature is available in Postfix 2.3 and later. </p> 4449 4450 4451 </DD> 4452 4453 <DT><b><a name="lmtp_tls_secure_cert_match">lmtp_tls_secure_cert_match</a> 4454 (default: nexthop)</b></DT><DD> 4455 4456 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> 4457 configuration parameter. See there for details. </p> 4458 4459 <p> This feature is available in Postfix 2.3 and later. </p> 4460 4461 4462 </DD> 4463 4464 <DT><b><a name="lmtp_tls_security_level">lmtp_tls_security_level</a> 4465 (default: empty)</b></DT><DD> 4466 4467 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> configuration 4468 parameter. See there for details. </p> 4469 4470 <p> This feature is available in Postfix 2.3 and later. </p> 4471 4472 4473 </DD> 4474 4475 <DT><b><a name="lmtp_tls_session_cache_database">lmtp_tls_session_cache_database</a> 4476 (default: empty)</b></DT><DD> 4477 4478 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> 4479 configuration parameter. See there for details. </p> 4480 4481 <p> This feature is available in Postfix 2.3 and later. </p> 4482 4483 4484 </DD> 4485 4486 <DT><b><a name="lmtp_tls_session_cache_timeout">lmtp_tls_session_cache_timeout</a> 4487 (default: 3600s)</b></DT><DD> 4488 4489 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a> 4490 configuration parameter. See there for details. </p> 4491 4492 <p> This feature is available in Postfix 2.3 and later. </p> 4493 4494 4495 </DD> 4496 4497 <DT><b><a name="lmtp_tls_verify_cert_match">lmtp_tls_verify_cert_match</a> 4498 (default: hostname)</b></DT><DD> 4499 4500 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> 4501 configuration parameter. See there for details. </p> 4502 4503 <p> This feature is available in Postfix 2.3 and later. </p> 4504 4505 4506 </DD> 4507 4508 <DT><b><a name="lmtp_use_tls">lmtp_use_tls</a> 4509 (default: no)</b></DT><DD> 4510 4511 <p> The LMTP-specific version of the <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a> configuration 4512 parameter. See there for details. </p> 4513 4514 <p> This feature is available in Postfix 2.3 and later. </p> 4515 4516 4517 </DD> 4518 4519 <DT><b><a name="lmtp_xforward_timeout">lmtp_xforward_timeout</a> 4520 (default: 300s)</b></DT><DD> 4521 4522 <p> 4523 The LMTP client time limit for sending the XFORWARD command, and 4524 for receiving the server response. 4525 </p> 4526 4527 <p> 4528 In case of problems the client does NOT try the next address on 4529 the mail exchanger list. 4530 </p> 4531 4532 <p> 4533 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 4534 The default time unit is s (seconds). 4535 </p> 4536 4537 <p> 4538 This feature is available in Postfix 2.1 and later. 4539 </p> 4540 4541 4542 </DD> 4543 4544 <DT><b><a name="local_command_shell">local_command_shell</a> 4545 (default: empty)</b></DT><DD> 4546 4547 <p> 4548 Optional shell program for <a href="local.8.html">local(8)</a> delivery to non-Postfix command. 4549 By default, non-Postfix commands are executed directly; commands 4550 are given to given to /bin/sh only when they contain shell meta 4551 characters or shell built-in commands. </p> 4552 4553 <p> "sendmail's restricted shell" (smrsh) is what most people will 4554 use in order to restrict what programs can be run from e.g. .forward 4555 files (smrsh is part of the Sendmail distribution). </p> 4556 4557 <p> Note: when a shell program is specified, it is invoked even 4558 when the command contains no shell built-in commands or meta 4559 characters. </p> 4560 4561 <p> 4562 Example: 4563 </p> 4564 4565 <pre> 4566 <a href="postconf.5.html#local_command_shell">local_command_shell</a> = /some/where/smrsh -c 4567 </pre> 4568 4569 4570 </DD> 4571 4572 <DT><b><a name="local_destination_concurrency_limit">local_destination_concurrency_limit</a> 4573 (default: 2)</b></DT><DD> 4574 4575 <p> The maximal number of parallel deliveries via the local mail 4576 delivery transport to the same recipient (when 4577 "<a href="postconf.5.html#local_destination_recipient_limit">local_destination_recipient_limit</a> = 1") or the maximal number of 4578 parallel deliveries to the same <a href="ADDRESS_CLASS_README.html#local_domain_class">local domain</a> (when 4579 "<a href="postconf.5.html#local_destination_recipient_limit">local_destination_recipient_limit</a> > 1"). This limit is enforced by 4580 the queue manager. The message delivery transport name is the first 4581 field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 4582 4583 <p> A low limit of 2 is recommended, just in case someone has an 4584 expensive shell command in a .forward file or in an alias (e.g., 4585 a mailing list manager). You don't want to run lots of those at 4586 the same time. </p> 4587 4588 4589 </DD> 4590 4591 <DT><b><a name="local_destination_recipient_limit">local_destination_recipient_limit</a> 4592 (default: 1)</b></DT><DD> 4593 4594 <p> The maximal number of recipients per message delivery via the 4595 local mail delivery transport. This limit is enforced by the queue 4596 manager. The message delivery transport name is the first field in 4597 the entry in the <a href="master.5.html">master.cf</a> file. </p> 4598 4599 <p> Setting this parameter to a value > 1 changes the meaning of 4600 <a href="postconf.5.html#local_destination_concurrency_limit">local_destination_concurrency_limit</a> from concurrency per recipient 4601 into concurrency per domain. </p> 4602 4603 4604 </DD> 4605 4606 <DT><b><a name="local_header_rewrite_clients">local_header_rewrite_clients</a> 4607 (default: <a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</a>)</b></DT><DD> 4608 4609 <p> Rewrite message header addresses in mail from these clients and 4610 update incomplete addresses with the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or 4611 $<a href="postconf.5.html#mydomain">mydomain</a>; either don't rewrite message headers from other clients 4612 at all, or rewrite message headers and update incomplete addresses 4613 with the domain specified in the <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> 4614 parameter. </p> 4615 4616 <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 4617 for details of how domain names are appended to incomplete addresses. 4618 </p> 4619 4620 <p> Specify a list of zero or more of the following: </p> 4621 4622 <dl> 4623 4624 <dt><b><a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</a></b></dt> 4625 4626 <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 4627 client IP address matches $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>. This is enabled by 4628 default. </dd> 4629 4630 <dt><b><a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a></b></dt> 4631 4632 <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 4633 client IP address matches any network or network address listed in 4634 $<a href="postconf.5.html#mynetworks">mynetworks</a>. This setting will not prevent remote mail header 4635 address rewriting when mail from a remote client is forwarded by 4636 a neighboring system. </dd> 4637 4638 <dt><b><a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a> </b></dt> 4639 4640 <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 4641 client is successfully authenticated via the <a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a> (AUTH) 4642 protocol. </dd> 4643 4644 <dt><b><a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> </b></dt> 4645 4646 <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 4647 client TLS certificate fingerprint is listed in $<a href="postconf.5.html#relay_clientcerts">relay_clientcerts</a>. 4648 The fingerprint digest algorithm is configurable via the 4649 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to 4650 Postfix version 2.5). </dd> 4651 4652 <dt><b><a href="postconf.5.html#permit_tls_all_clientcerts">permit_tls_all_clientcerts</a> </b></dt> 4653 4654 <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 4655 client TLS certificate is successfully verified, regardless of 4656 whether it is listed on the server, and regardless of the certifying 4657 authority. </dd> 4658 4659 <dt><b><a name="check_address_map">check_address_map</a> <i><a href="DATABASE_README.html">type:table</a></i> </b></dt> 4660 4661 <dt><b><i><a href="DATABASE_README.html">type:table</a></i> </b></dt> 4662 4663 <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 4664 client IP address matches the specified lookup table. 4665 The lookup result is ignored, and no subnet lookup is done. This 4666 is suitable for, e.g., pop-before-smtp lookup tables. </dd> 4667 4668 </dl> 4669 4670 <p> Examples: </p> 4671 4672 <p> The Postfix < 2.2 backwards compatible setting: always rewrite 4673 message headers, and always append my own domain to incomplete 4674 header addresses. </p> 4675 4676 <blockquote> 4677 <pre> 4678 <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all 4679 </pre> 4680 </blockquote> 4681 4682 <p> The purist (and default) setting: rewrite headers only in mail 4683 from Postfix sendmail and in SMTP mail from this machine. </p> 4684 4685 <blockquote> 4686 <pre> 4687 <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> 4688 </pre> 4689 </blockquote> 4690 4691 <p> The intermediate setting: rewrite header addresses and append 4692 $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> information only with mail from Postfix 4693 sendmail, from local clients, or from authorized SMTP clients. </p> 4694 4695 <p> Note: this setting will not prevent remote mail header address 4696 rewriting when mail from a remote client is forwarded by a neighboring 4697 system. </p> 4698 4699 <blockquote> 4700 <pre> 4701 <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, 4702 <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a> <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> 4703 <a href="postconf.5.html#check_address_map">check_address_map</a> hash:/etc/postfix/pop-before-smtp 4704 </pre> 4705 </blockquote> 4706 4707 4708 </DD> 4709 4710 <DT><b><a name="local_recipient_maps">local_recipient_maps</a> 4711 (default: <a href="proxymap.8.html">proxy</a>:unix:passwd.byname $<a href="postconf.5.html#alias_maps">alias_maps</a>)</b></DT><DD> 4712 4713 <p> Lookup tables with all names or addresses of local recipients: 4714 a recipient address is local when its domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, 4715 $<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 4716 wild-card for domains that do not have a valid recipient list. 4717 Technically, tables listed with $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> are used as 4718 lists: Postfix needs to know only if a lookup string is found or 4719 not, but it does not use the result from table lookup. </p> 4720 4721 <p> 4722 If this parameter is non-empty (the default), then the Postfix SMTP 4723 server will reject mail for unknown local users. 4724 </p> 4725 4726 <p> 4727 To turn off local recipient checking in the Postfix SMTP server, 4728 specify "<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> =" (i.e. empty). 4729 </p> 4730 4731 <p> 4732 The default setting assumes that you use the default Postfix local 4733 delivery agent for local delivery. You need to update the 4734 <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> setting if: 4735 </p> 4736 4737 <ul> 4738 4739 <li>You redefine the local delivery agent in <a href="master.5.html">master.cf</a>. 4740 4741 <li>You redefine the "<a href="postconf.5.html#local_transport">local_transport</a>" setting in <a href="postconf.5.html">main.cf</a>. 4742 4743 <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>" 4744 feature of the Postfix <a href="local.8.html">local(8)</a> delivery agent. 4745 4746 </ul> 4747 4748 <p> 4749 Details are described in the <a href="LOCAL_RECIPIENT_README.html">LOCAL_RECIPIENT_README</a> file. 4750 </p> 4751 4752 <p> 4753 Beware: if the Postfix SMTP server runs chrooted, you need to access 4754 the passwd file via the <a href="proxymap.8.html">proxymap(8)</a> service, in order to overcome 4755 chroot access restrictions. The alternative, maintaining a copy of 4756 the system password file in the chroot jail is not practical. 4757 </p> 4758 4759 <p> 4760 Examples: 4761 </p> 4762 4763 <pre> 4764 <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> = 4765 </pre> 4766 4767 4768 </DD> 4769 4770 <DT><b><a name="local_transport">local_transport</a> 4771 (default: <a href="local.8.html">local</a>:$<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 4772 4773 <p> The default mail delivery transport and next-hop destination 4774 for final delivery to domains listed with <a href="postconf.5.html#mydestination">mydestination</a>, and for 4775 [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>. 4776 This information can be overruled with the <a href="transport.5.html">transport(5)</a> table. </p> 4777 4778 <p> 4779 By default, local mail is delivered to the transport called "local", 4780 which is just the name of a service that is defined the <a href="master.5.html">master.cf</a> file. 4781 </p> 4782 4783 <p> 4784 Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i> 4785 is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>. 4786 The <i>:nexthop</i> part is optional. For more details see the 4787 <a href="transport.5.html">transport(5)</a> manual page. 4788 </p> 4789 4790 <p> 4791 Beware: if you override the default local delivery agent then you 4792 need to review the <a href="LOCAL_RECIPIENT_README.html">LOCAL_RECIPIENT_README</a> document, otherwise the 4793 SMTP server may reject mail for local recipients. 4794 </p> 4795 4796 4797 </DD> 4798 4799 <DT><b><a name="luser_relay">luser_relay</a> 4800 (default: empty)</b></DT><DD> 4801 4802 <p> 4803 Optional catch-all destination for unknown <a href="local.8.html">local(8)</a> recipients. 4804 By default, mail for unknown recipients in domains that match 4805 $<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 4806 as undeliverable. 4807 </p> 4808 4809 <p> 4810 The following $name expansions are done on <a href="postconf.5.html#luser_relay">luser_relay</a>: 4811 </p> 4812 4813 <dl> 4814 4815 <dt><b>$domain</b></dt> 4816 4817 <dd>The recipient domain. </dd> 4818 4819 <dt><b>$extension</b></dt> 4820 4821 <dd>The recipient address extension. </dd> 4822 4823 <dt><b>$home</b></dt> 4824 4825 <dd>The recipient's home directory. </dd> 4826 4827 <dt><b>$local</b></dt> 4828 4829 <dd>The entire recipient address localpart. </dd> 4830 4831 <dt><b>$recipient</b></dt> 4832 4833 <dd>The full recipient address. </dd> 4834 4835 <dt><b>$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b></dt> 4836 4837 <dd>The system-wide recipient address extension delimiter. </dd> 4838 4839 <dt><b>$shell</b></dt> 4840 4841 <dd>The recipient's login shell. </dd> 4842 4843 <dt><b>$user</b></dt> 4844 4845 <dd>The recipient username. </dd> 4846 4847 <dt><b>${name?value}</b></dt> 4848 4849 <dd>Expands to <i>value</i> when <i>$name</i> has a non-empty value. </dd> 4850 4851 <dt><b>${name:value}</b></dt> 4852 4853 <dd>Expands to <i>value</i> when <i>$name</i> has an empty value. </dd> 4854 4855 </dl> 4856 4857 <p> 4858 Instead of $name you can also specify ${name} or $(name). 4859 </p> 4860 4861 <p> 4862 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. 4863 </p> 4864 4865 <p> 4866 Note: if you use this feature for accounts not in the UNIX password 4867 file, then you must specify "<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> =" (i.e. empty) 4868 in the <a href="postconf.5.html">main.cf</a> file, otherwise the Postfix SMTP server will reject mail 4869 for non-UNIX accounts with "User unknown in local recipient table". 4870 </p> 4871 4872 <p> 4873 Examples: 4874 </p> 4875 4876 <pre> 4877 <a href="postconf.5.html#luser_relay">luser_relay</a> = $user (a] other.host 4878 <a href="postconf.5.html#luser_relay">luser_relay</a> = $local (a] other.host 4879 <a href="postconf.5.html#luser_relay">luser_relay</a> = admin+$local 4880 </pre> 4881 4882 4883 </DD> 4884 4885 <DT><b><a name="mail_name">mail_name</a> 4886 (default: Postfix)</b></DT><DD> 4887 4888 <p> 4889 The mail system name that is displayed in Received: headers, in 4890 the SMTP greeting banner, and in bounced mail. 4891 </p> 4892 4893 4894 </DD> 4895 4896 <DT><b><a name="mail_owner">mail_owner</a> 4897 (default: postfix)</b></DT><DD> 4898 4899 <p> 4900 The UNIX system account that owns the Postfix queue and most Postfix 4901 daemon processes. Specify the name of a user account that does 4902 not share a group with other accounts and that owns no other files 4903 or processes on the system. In particular, don't specify nobody 4904 or daemon. PLEASE USE A DEDICATED USER ID AND GROUP ID. 4905 </p> 4906 4907 <p> 4908 When this parameter value is changed you need to re-run "<b>postfix 4909 set-permissions</b>" (with Postfix version 2.0 and earlier: 4910 "<b>/etc/postfix/post-install set-permissions</b>". 4911 </p> 4912 4913 4914 </DD> 4915 4916 <DT><b><a name="mail_release_date">mail_release_date</a> 4917 (default: see "postconf -d" output)</b></DT><DD> 4918 4919 <p> 4920 The Postfix release date, in "YYYYMMDD" format. 4921 </p> 4922 4923 4924 </DD> 4925 4926 <DT><b><a name="mail_spool_directory">mail_spool_directory</a> 4927 (default: see "postconf -d" output)</b></DT><DD> 4928 4929 <p> 4930 The directory where <a href="local.8.html">local(8)</a> UNIX-style mailboxes are kept. The 4931 default setting depends on the system type. Specify a name ending 4932 in / for maildir-style delivery. 4933 </p> 4934 4935 <p> 4936 Note: maildir delivery is done with the privileges of the recipient. 4937 If you use the <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a> setting for maildir style 4938 delivery, then you must create the top-level maildir directory in 4939 advance. Postfix will not create it. 4940 </p> 4941 4942 <p> 4943 Examples: 4944 </p> 4945 4946 <pre> 4947 <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a> = /var/mail 4948 <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a> = /var/spool/mail 4949 </pre> 4950 4951 4952 </DD> 4953 4954 <DT><b><a name="mail_version">mail_version</a> 4955 (default: see "postconf -d" output)</b></DT><DD> 4956 4957 <p> 4958 The version of the mail system. Stable releases are named 4959 <i>major</i>.<i>minor</i>.<i>patchlevel</i>. Experimental releases 4960 also include the release date. The version string can be used in, 4961 for example, the SMTP greeting banner. 4962 </p> 4963 4964 4965 </DD> 4966 4967 <DT><b><a name="mailbox_command">mailbox_command</a> 4968 (default: empty)</b></DT><DD> 4969 4970 <p> 4971 Optional external command that the <a href="local.8.html">local(8)</a> delivery agent should 4972 use for mailbox delivery. The command is run with the user ID and 4973 the primary group ID privileges of the recipient. Exception: 4974 command delivery for root executes with $<a href="postconf.5.html#default_privs">default_privs</a> privileges. 4975 This is not a problem, because 1) mail for root should always be 4976 aliased to a real user and 2) don't log in as root, use "su" instead. 4977 </p> 4978 4979 <p> 4980 The following environment variables are exported to the command: 4981 </p> 4982 4983 <dl> 4984 4985 <dt><b>CLIENT_ADDRESS</b></dt> 4986 4987 <dd>Remote client network address. Available in Postfix version 2.2 and 4988 later. </dd> 4989 4990 <dt><b>CLIENT_HELO</b></dt> 4991 4992 <dd>Remote client EHLO command parameter. Available in Postfix version 2.2 4993 and later.</dd> 4994 4995 <dt><b>CLIENT_HOSTNAME</b></dt> 4996 4997 <dd>Remote client hostname. Available in Postfix version 2.2 and later. 4998 </dd> 4999 5000 <dt><b>CLIENT_PROTOCOL</b></dt> 5001 5002 <dd>Remote client protocol. Available in Postfix version 2.2 and later. 5003 </dd> 5004 5005 <dt><b>DOMAIN</b></dt> 5006 5007 <dd>The domain part of the recipient address. </dd> 5008 5009 <dt><b>EXTENSION</b></dt> 5010 5011 <dd>The optional address extension. </dd> 5012 5013 <dt><b>HOME</b></dt> 5014 5015 <dd>The recipient home directory. </dd> 5016 5017 <dt><b>LOCAL</b></dt> 5018 5019 <dd>The recipient address localpart. </dd> 5020 5021 <dt><b>LOGNAME</b></dt> 5022 5023 <dd>The recipient's username. </dd> 5024 5025 <dt><b>ORIGINAL_RECIPIENT</b></dt> 5026 5027 <dd>The entire recipient address, before any address rewriting or 5028 aliasing. </dd> 5029 5030 <dt><b>RECIPIENT</b></dt> 5031 5032 <dd>The full recipient address. </dd> 5033 5034 <dt><b>SASL_METHOD</b></dt> 5035 5036 <dd>SASL authentication method specified in the remote client AUTH 5037 command. Available in Postfix version 2.2 and later. </dd> 5038 5039 <dt><b>SASL_SENDER</b></dt> 5040 5041 <dd>SASL sender address specified in the remote client MAIL FROM 5042 command. Available in Postfix version 2.2 and later. </dd> 5043 5044 <dt><b>SASL_USER</b></dt> 5045 5046 <dd>SASL username specified in the remote client AUTH command. 5047 Available in Postfix version 2.2 and later. </dd> 5048 5049 <dt><b>SENDER</b></dt> 5050 5051 <dd>The full sender address. </dd> 5052 5053 <dt><b>SHELL</b></dt> 5054 5055 <dd>The recipient's login shell. </dd> 5056 5057 <dt><b>USER</b></dt> 5058 5059 <dd>The recipient username. </dd> 5060 5061 </dl> 5062 5063 <p> 5064 Unlike other Postfix configuration parameters, the <a href="postconf.5.html#mailbox_command">mailbox_command</a> 5065 parameter is not subjected to $name substitutions. This is to make 5066 it easier to specify shell syntax (see example below). 5067 </p> 5068 5069 <p> 5070 If you can, avoid shell meta characters because they will force 5071 Postfix to run an expensive shell process. If you're delivering 5072 via Procmail then running a shell won't make a noticeable difference 5073 in the total cost. 5074 </p> 5075 5076 <p> 5077 Note: if you use the <a href="postconf.5.html#mailbox_command">mailbox_command</a> feature to deliver mail 5078 system-wide, you must set up an alias that forwards mail for root 5079 to a real user. 5080 </p> 5081 5082 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 5083 is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>, 5084 <a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>, 5085 <a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p> 5086 5087 <p> 5088 Examples: 5089 </p> 5090 5091 <pre> 5092 <a href="postconf.5.html#mailbox_command">mailbox_command</a> = /some/where/procmail 5093 <a href="postconf.5.html#mailbox_command">mailbox_command</a> = /some/where/procmail -a "$EXTENSION" 5094 <a href="postconf.5.html#mailbox_command">mailbox_command</a> = /some/where/maildrop -d "$USER" 5095 -f "$SENDER" "$EXTENSION" 5096 </pre> 5097 5098 5099 </DD> 5100 5101 <DT><b><a name="mailbox_command_maps">mailbox_command_maps</a> 5102 (default: empty)</b></DT><DD> 5103 5104 <p> 5105 Optional lookup tables with per-recipient external commands to use 5106 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>. 5107 </p> 5108 5109 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 5110 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>, 5111 <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>, 5112 <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> 5113 5114 5115 </DD> 5116 5117 <DT><b><a name="mailbox_delivery_lock">mailbox_delivery_lock</a> 5118 (default: see "postconf -d" output)</b></DT><DD> 5119 5120 <p> 5121 How to lock a UNIX-style <a href="local.8.html">local(8)</a> mailbox before attempting delivery. 5122 For a list of available file locking methods, use the "<b>postconf 5123 -l</b>" command. 5124 </p> 5125 5126 <p> 5127 This setting is ignored with <b>maildir</b> style delivery, 5128 because such deliveries are safe without explicit locks. 5129 </p> 5130 5131 <p> 5132 Note: The <b>dotlock</b> method requires that the recipient UID or 5133 GID has write access to the parent directory of the mailbox file. 5134 </p> 5135 5136 <p> 5137 Note: the default setting of this parameter is system dependent. 5138 </p> 5139 5140 5141 </DD> 5142 5143 <DT><b><a name="mailbox_size_limit">mailbox_size_limit</a> 5144 (default: 51200000)</b></DT><DD> 5145 5146 <p> The maximal size of any <a href="local.8.html">local(8)</a> individual mailbox or maildir 5147 file, or zero (no limit). In fact, this limits the size of any 5148 file that is written to upon local delivery, including files written 5149 by external commands that are executed by the <a href="local.8.html">local(8)</a> delivery 5150 agent. </p> 5151 5152 <p> 5153 This limit must not be smaller than the message size limit. 5154 </p> 5155 5156 5157 </DD> 5158 5159 <DT><b><a name="mailbox_transport">mailbox_transport</a> 5160 (default: empty)</b></DT><DD> 5161 5162 <p> 5163 Optional message delivery transport that the <a href="local.8.html">local(8)</a> delivery 5164 agent should use for mailbox delivery to all local recipients, 5165 whether or not they are found in the UNIX passwd database. 5166 </p> 5167 5168 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 5169 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>, 5170 <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>, 5171 <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> 5172 5173 5174 </DD> 5175 5176 <DT><b><a name="mailbox_transport_maps">mailbox_transport_maps</a> 5177 (default: empty)</b></DT><DD> 5178 5179 <p> Optional lookup tables with per-recipient message delivery 5180 transports to use for <a href="local.8.html">local(8)</a> mailbox delivery, whether or not the 5181 recipients are found in the UNIX passwd database. </p> 5182 5183 <p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low 5184 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>, 5185 <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>, 5186 <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> 5187 5188 <p> For safety reasons, this feature does not allow $number 5189 substitutions in regular expression maps. </p> 5190 5191 <p> This feature is available in Postfix 2.3 and later. </p> 5192 5193 5194 </DD> 5195 5196 <DT><b><a name="mailq_path">mailq_path</a> 5197 (default: see "postconf -d" output)</b></DT><DD> 5198 5199 <p> 5200 Sendmail compatibility feature that specifies where the Postfix 5201 <a href="mailq.1.html">mailq(1)</a> command is installed. This command can be used to 5202 list the Postfix mail queue. 5203 </p> 5204 5205 5206 </DD> 5207 5208 <DT><b><a name="manpage_directory">manpage_directory</a> 5209 (default: see "postconf -d" output)</b></DT><DD> 5210 5211 <p> 5212 Where the Postfix manual pages are installed. 5213 </p> 5214 5215 5216 </DD> 5217 5218 <DT><b><a name="maps_rbl_domains">maps_rbl_domains</a> 5219 (default: empty)</b></DT><DD> 5220 5221 <p> 5222 Obsolete feature: use the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> feature instead. 5223 </p> 5224 5225 5226 </DD> 5227 5228 <DT><b><a name="maps_rbl_reject_code">maps_rbl_reject_code</a> 5229 (default: 554)</b></DT><DD> 5230 5231 <p> 5232 The numerical Postfix SMTP server response code when a remote SMTP 5233 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>, 5234 <a href="postconf.5.html#reject_rhsbl_sender">reject_rhsbl_sender</a> or <a href="postconf.5.html#reject_rhsbl_recipient">reject_rhsbl_recipient</a> restriction. 5235 </p> 5236 5237 <p> 5238 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 5239 </p> 5240 5241 5242 </DD> 5243 5244 <DT><b><a name="masquerade_classes">masquerade_classes</a> 5245 (default: envelope_sender, header_sender, header_recipient)</b></DT><DD> 5246 5247 <p> 5248 What addresses are subject to address masquerading. 5249 </p> 5250 5251 <p> 5252 By default, address masquerading is limited to envelope sender 5253 addresses, and to header sender and header recipient addresses. 5254 This allows you to use address masquerading on a mail gateway while 5255 still being able to forward mail to users on individual machines. 5256 </p> 5257 5258 <p> 5259 Specify zero or more of: envelope_sender, envelope_recipient, 5260 header_sender, header_recipient 5261 </p> 5262 5263 5264 </DD> 5265 5266 <DT><b><a name="masquerade_domains">masquerade_domains</a> 5267 (default: empty)</b></DT><DD> 5268 5269 <p> 5270 Optional list of domains whose subdomain structure will be stripped 5271 off in email addresses. 5272 </p> 5273 5274 <p> 5275 The list is processed left to right, and processing stops at the 5276 first match. Thus, 5277 </p> 5278 5279 <blockquote> 5280 <pre> 5281 <a href="postconf.5.html#masquerade_domains">masquerade_domains</a> = foo.example.com example.com 5282 </pre> 5283 </blockquote> 5284 5285 <p> 5286 strips "user (a] any.thing.foo.example.com" to "user (a] foo.example.com", 5287 but strips "user (a] any.thing.else.example.com" to "user (a] example.com". 5288 </p> 5289 5290 <p> 5291 A domain name prefixed with ! means do not masquerade this domain 5292 or its subdomains. Thus, 5293 </p> 5294 5295 <blockquote> 5296 <pre> 5297 <a href="postconf.5.html#masquerade_domains">masquerade_domains</a> = !foo.example.com example.com 5298 </pre> 5299 </blockquote> 5300 5301 <p> 5302 does not change "user (a] any.thing.foo.example.com" or "user (a] foo.example.com", 5303 but strips "user (a] any.thing.else.example.com" to "user (a] example.com". 5304 </p> 5305 5306 <p> Note: with Postfix version 2.2, message header address masquerading 5307 happens only when message header address rewriting is enabled: </p> 5308 5309 <ul> 5310 5311 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 5312 5313 <li> The message is received from a network client that matches 5314 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 5315 5316 <li> The message is received from the network, and the 5317 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 5318 5319 </ul> 5320 5321 <p> To get the behavior before Postfix version 2.2, specify 5322 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 5323 5324 <p> 5325 Example: 5326 </p> 5327 5328 <pre> 5329 <a href="postconf.5.html#masquerade_domains">masquerade_domains</a> = $<a href="postconf.5.html#mydomain">mydomain</a> 5330 </pre> 5331 5332 5333 </DD> 5334 5335 <DT><b><a name="masquerade_exceptions">masquerade_exceptions</a> 5336 (default: empty)</b></DT><DD> 5337 5338 <p> 5339 Optional list of user names that are not subjected to address 5340 masquerading, even when their address matches $<a href="postconf.5.html#masquerade_domains">masquerade_domains</a>. 5341 </p> 5342 5343 <p> 5344 By default, address masquerading makes no exceptions. 5345 </p> 5346 5347 <p> 5348 Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns, 5349 separated by commas and/or whitespace. The list is matched left to 5350 right, and the search stops on the first match. A "/file/name" 5351 pattern is replaced 5352 by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name 5353 matches a lookup key (the lookup result is ignored). Continue long 5354 lines by starting the next line with whitespace. Specify "!pattern" 5355 to exclude a name from the list. The form "!/file/name" is supported 5356 only in Postfix version 2.4 and later. </p> 5357 5358 <p> 5359 Examples: 5360 </p> 5361 5362 <pre> 5363 <a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a> = root, mailer-daemon 5364 <a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a> = root 5365 </pre> 5366 5367 5368 </DD> 5369 5370 <DT><b><a name="master_service_disable">master_service_disable</a> 5371 (default: empty)</b></DT><DD> 5372 5373 <p> Selectively disable <a href="master.8.html">master(8)</a> listener ports by service type 5374 or by service name and type. Specify a list of service types 5375 ("inet", "unix", "fifo", or "pass") or "name.type" tuples, where 5376 "name" is the first field of a <a href="master.5.html">master.cf</a> entry and "type" is a 5377 service type. As with other Postfix matchlists, a search stops at 5378 the first match. Specify "!pattern" to exclude a service from the 5379 list. By default, all <a href="master.8.html">master(8)</a> listener ports are enabled. </p> 5380 5381 <p> Note: this feature does not support "/file/name" or "<a href="DATABASE_README.html">type:table</a>" 5382 patterns, nor does it support wildcards such as "*" or "all". This 5383 is intentional. </p> 5384 5385 <p> Examples: </p> 5386 5387 <pre> 5388 # Turn on all <a href="master.8.html">master(8)</a> listener ports (the default). 5389 <a href="postconf.5.html#master_service_disable">master_service_disable</a> = 5390 # Turn off only the main SMTP listener port. 5391 <a href="postconf.5.html#master_service_disable">master_service_disable</a> = smtp.inet 5392 # Turn off all TCP/IP listener ports. 5393 <a href="postconf.5.html#master_service_disable">master_service_disable</a> = inet 5394 # Turn off all TCP/IP listener ports except "foo". 5395 <a href="postconf.5.html#master_service_disable">master_service_disable</a> = !foo.inet, inet 5396 </pre> 5397 5398 <p> This feature is available in Postfix 2.6 and later. </p> 5399 5400 5401 </DD> 5402 5403 <DT><b><a name="max_idle">max_idle</a> 5404 (default: 100s)</b></DT><DD> 5405 5406 <p> 5407 The maximum amount of time that an idle Postfix daemon process waits 5408 for an incoming connection before terminating voluntarily. This 5409 parameter 5410 is ignored by the Postfix queue manager and by other long-lived 5411 Postfix daemon processes. 5412 </p> 5413 5414 <p> 5415 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 5416 The default time unit is s (seconds). 5417 </p> 5418 5419 5420 </DD> 5421 5422 <DT><b><a name="max_use">max_use</a> 5423 (default: 100)</b></DT><DD> 5424 5425 <p> 5426 The maximal number of incoming connections that a Postfix daemon 5427 process will service before terminating voluntarily. This parameter 5428 is ignored by the Postfix queue 5429 manager and by other long-lived Postfix daemon processes. 5430 </p> 5431 5432 5433 </DD> 5434 5435 <DT><b><a name="maximal_backoff_time">maximal_backoff_time</a> 5436 (default: 4000s)</b></DT><DD> 5437 5438 <p> 5439 The maximal time between attempts to deliver a deferred message. 5440 </p> 5441 5442 <p> This parameter should be set to a value greater than or equal 5443 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> 5444 5445 <p> 5446 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 5447 The default time unit is s (seconds). 5448 </p> 5449 5450 5451 </DD> 5452 5453 <DT><b><a name="maximal_queue_lifetime">maximal_queue_lifetime</a> 5454 (default: 5d)</b></DT><DD> 5455 5456 <p> 5457 The maximal time a message is queued before it is sent back as 5458 undeliverable. 5459 </p> 5460 5461 <p> 5462 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 5463 The default time unit is d (days). 5464 </p> 5465 5466 <p> 5467 Specify 0 when mail delivery should be tried only once. 5468 </p> 5469 5470 5471 </DD> 5472 5473 <DT><b><a name="message_reject_characters">message_reject_characters</a> 5474 (default: empty)</b></DT><DD> 5475 5476 <p> The set of characters that Postfix will reject in message 5477 content. The usual C-like escape sequences are recognized: <tt>\a 5478 \b \f \n \r \t \v \<i>ddd</i></tt> (up to three octal digits) and 5479 <tt>\\</tt>. </p> 5480 5481 <p> Example: </p> 5482 5483 <pre> 5484 <a href="postconf.5.html#message_reject_characters">message_reject_characters</a> = \0 5485 </pre> 5486 5487 <p> This feature is available in Postfix 2.3 and later. </p> 5488 5489 5490 </DD> 5491 5492 <DT><b><a name="message_size_limit">message_size_limit</a> 5493 (default: 10240000)</b></DT><DD> 5494 5495 <p> 5496 The maximal size in bytes of a message, including envelope information. 5497 </p> 5498 5499 <p> Note: be careful when making changes. Excessively small values 5500 will result in the loss of non-delivery notifications, when a bounce 5501 message size exceeds the local or remote MTA's message size limit. 5502 </p> 5503 5504 5505 </DD> 5506 5507 <DT><b><a name="message_strip_characters">message_strip_characters</a> 5508 (default: empty)</b></DT><DD> 5509 5510 <p> The set of characters that Postfix will remove from message 5511 content. The usual C-like escape sequences are recognized: <tt>\a 5512 \b \f \n \r \t \v \<i>ddd</i></tt> (up to three octal digits) and 5513 <tt>\\</tt>. </p> 5514 5515 <p> Example: </p> 5516 5517 <pre> 5518 <a href="postconf.5.html#message_strip_characters">message_strip_characters</a> = \0 5519 </pre> 5520 5521 <p> This feature is available in Postfix 2.3 and later. </p> 5522 5523 5524 </DD> 5525 5526 <DT><b><a name="milter_command_timeout">milter_command_timeout</a> 5527 (default: 30s)</b></DT><DD> 5528 5529 <p> The time limit for sending an SMTP command to a Milter (mail 5530 filter) application, and for receiving the response. </p> 5531 5532 <p> Specify a non-zero time value (an integral value plus an optional 5533 one-letter suffix that specifies the time unit). </p> 5534 5535 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 5536 (weeks). The default time unit is s (seconds). </p> 5537 5538 <p> This feature is available in Postfix 2.3 and later. </p> 5539 5540 5541 </DD> 5542 5543 <DT><b><a name="milter_connect_macros">milter_connect_macros</a> 5544 (default: see "postconf -d" output)</b></DT><DD> 5545 5546 <p> The macros that are sent to Milter (mail filter) applications 5547 after completion of an SMTP connection. See <a href="MILTER_README.html">MILTER_README</a> 5548 for a list of available macro names and their meanings. </p> 5549 5550 <p> This feature is available in Postfix 2.3 and later. </p> 5551 5552 5553 </DD> 5554 5555 <DT><b><a name="milter_connect_timeout">milter_connect_timeout</a> 5556 (default: 30s)</b></DT><DD> 5557 5558 <p> The time limit for connecting to a Milter (mail filter) 5559 application, and for negotiating protocol options. </p> 5560 5561 <p> Specify a non-zero time value (an integral value plus an optional 5562 one-letter suffix that specifies the time unit). </p> 5563 5564 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 5565 (weeks). The default time unit is s (seconds). </p> 5566 5567 <p> This feature is available in Postfix 2.3 and later. </p> 5568 5569 5570 </DD> 5571 5572 <DT><b><a name="milter_content_timeout">milter_content_timeout</a> 5573 (default: 300s)</b></DT><DD> 5574 5575 <p> The time limit for sending message content to a Milter (mail 5576 filter) application, and for receiving the response. </p> 5577 5578 <p> Specify a non-zero time value (an integral value plus an optional 5579 one-letter suffix that specifies the time unit). </p> 5580 5581 <p> Time units: s (seconds), m (minutes), h (hours), d (days), w 5582 (weeks). The default time unit is s (seconds). </p> 5583 5584 <p> This feature is available in Postfix 2.3 and later. </p> 5585 5586 5587 </DD> 5588 5589 <DT><b><a name="milter_data_macros">milter_data_macros</a> 5590 (default: see "postconf -d" output)</b></DT><DD> 5591 5592 <p> The macros that are sent to version 4 or higher Milter (mail 5593 filter) applications after the SMTP DATA command. See <a href="MILTER_README.html">MILTER_README</a> 5594 for a list of available macro names and their meanings. </p> 5595 5596 <p> This feature is available in Postfix 2.3 and later. </p> 5597 5598 5599 </DD> 5600 5601 <DT><b><a name="milter_default_action">milter_default_action</a> 5602 (default: tempfail)</b></DT><DD> 5603 5604 <p> The default action when a Milter (mail filter) application is 5605 unavailable or mis-configured. Specify one of the following: </p> 5606 5607 <dl compact> 5608 5609 <dt>accept</dt> <dd>Proceed as if the mail filter was not present. 5610 </dd> 5611 5612 <dt>reject</dt> <dd>Reject all further commands in this session 5613 with a permanent status code.</dd> 5614 5615 <dt>tempfail</dt> <dd>Reject all further commands in this session 5616 with a temporary status code. </dd> 5617 5618 <dt>quarantine</dt> <dd>Like "accept", but freeze the message in 5619 the "<a href="QSHAPE_README.html#hold_queue">hold" queue</a>. Available with Postfix 2.6 and later. </dd> 5620 5621 </dl> 5622 5623 <p> This feature is available in Postfix 2.3 and later. </p> 5624 5625 5626 </DD> 5627 5628 <DT><b><a name="milter_end_of_data_macros">milter_end_of_data_macros</a> 5629 (default: see "postconf -d" output)</b></DT><DD> 5630 5631 <p> The macros that are sent to Milter (mail filter) applications 5632 after the message end-of-data. See <a href="MILTER_README.html">MILTER_README</a> for a list of 5633 available macro names and their meanings. </p> 5634 5635 <p> This feature is available in Postfix 2.3 and later. </p> 5636 5637 5638 </DD> 5639 5640 <DT><b><a name="milter_end_of_header_macros">milter_end_of_header_macros</a> 5641 (default: see "postconf -d" output)</b></DT><DD> 5642 5643 <p> The macros that are sent to Milter (mail filter) applications 5644 after the end of the message header. See <a href="MILTER_README.html">MILTER_README</a> for a list 5645 of available macro names and their meanings. </p> 5646 5647 <p> This feature is available in Postfix 2.5 and later. </p> 5648 5649 5650 </DD> 5651 5652 <DT><b><a name="milter_helo_macros">milter_helo_macros</a> 5653 (default: see "postconf -d" output)</b></DT><DD> 5654 5655 <p> The macros that are sent to Milter (mail filter) applications 5656 after the SMTP HELO or EHLO command. See 5657 <a href="MILTER_README.html">MILTER_README</a> for a list of available macro names and their meanings. 5658 </p> 5659 5660 <p> This feature is available in Postfix 2.3 and later. </p> 5661 5662 5663 </DD> 5664 5665 <DT><b><a name="milter_macro_daemon_name">milter_macro_daemon_name</a> 5666 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 5667 5668 <p> The {daemon_name} macro value for Milter (mail filter) applications. 5669 See <a href="MILTER_README.html">MILTER_README</a> for a list of available macro names and their 5670 meanings. </p> 5671 5672 <p> This feature is available in Postfix 2.3 and later. </p> 5673 5674 5675 </DD> 5676 5677 <DT><b><a name="milter_macro_v">milter_macro_v</a> 5678 (default: $<a href="postconf.5.html#mail_name">mail_name</a> $<a href="postconf.5.html#mail_version">mail_version</a>)</b></DT><DD> 5679 5680 <p> The {v} macro value for Milter (mail filter) applications. 5681 See <a href="MILTER_README.html">MILTER_README</a> for a list of available macro names and their 5682 meanings. </p> 5683 5684 <p> This feature is available in Postfix 2.3 and later. </p> 5685 5686 5687 </DD> 5688 5689 <DT><b><a name="milter_mail_macros">milter_mail_macros</a> 5690 (default: see "postconf -d" output)</b></DT><DD> 5691 5692 <p> The macros that are sent to Milter (mail filter) applications 5693 after the SMTP MAIL FROM command. See <a href="MILTER_README.html">MILTER_README</a> 5694 for a list of available macro names and their meanings. </p> 5695 5696 <p> This feature is available in Postfix 2.3 and later. </p> 5697 5698 5699 </DD> 5700 5701 <DT><b><a name="milter_protocol">milter_protocol</a> 5702 (default: 6)</b></DT><DD> 5703 5704 <p> The mail filter protocol version and optional protocol extensions 5705 for communication with a Milter application; prior to Postfix 2.6 5706 the default protocol is 2. Postfix 5707 sends this version number during the initial protocol handshake. 5708 It should match the version number that is expected by the mail 5709 filter application (or by its Milter library). </p> 5710 5711 <p>Protocol versions: </p> 5712 5713 <dl compact> 5714 5715 <dt>2</dt> <dd>Use Sendmail 8 mail filter protocol version 2 (default 5716 with Sendmail version 8.11 .. 8.13 and Postfix version 2.3 .. 5717 2.5).</dd> 5718 5719 <dt>3</dt> <dd>Use Sendmail 8 mail filter protocol version 3.</dd> 5720 5721 <dt>4</dt> <dd>Use Sendmail 8 mail filter protocol version 4.</dd> 5722 5723 <dt>6</dt> <dd>Use Sendmail 8 mail filter protocol version 6 (default 5724 with Sendmail version 8.14 and Postfix version 2.6).</dd> 5725 5726 </dl> 5727 5728 <p>Protocol extensions: </p> 5729 5730 <dl compact> 5731 5732 <dt>no_header_reply</dt> <dd> Specify this when the Milter application 5733 will not reply for each individual message header.</dd> 5734 5735 </dl> 5736 5737 <p> This feature is available in Postfix 2.3 and later. </p> 5738 5739 5740 </DD> 5741 5742 <DT><b><a name="milter_rcpt_macros">milter_rcpt_macros</a> 5743 (default: see "postconf -d" output)</b></DT><DD> 5744 5745 <p> The macros that are sent to Milter (mail filter) applications 5746 after the SMTP RCPT TO command. See <a href="MILTER_README.html">MILTER_README</a> 5747 for a list of available macro names and their meanings. </p> 5748 5749 <p> This feature is available in Postfix 2.3 and later. </p> 5750 5751 5752 </DD> 5753 5754 <DT><b><a name="milter_unknown_command_macros">milter_unknown_command_macros</a> 5755 (default: see "postconf -d" output)</b></DT><DD> 5756 5757 <p> The macros that are sent to version 3 or higher Milter (mail 5758 filter) applications after an unknown SMTP command. See <a href="MILTER_README.html">MILTER_README</a> 5759 for a list of available macro names and their meanings. </p> 5760 5761 <p> This feature is available in Postfix 2.3 and later. </p> 5762 5763 5764 </DD> 5765 5766 <DT><b><a name="mime_boundary_length_limit">mime_boundary_length_limit</a> 5767 (default: 2048)</b></DT><DD> 5768 5769 <p> 5770 The maximal length of MIME multipart boundary strings. The MIME 5771 processor is unable to distinguish between boundary strings that 5772 do not differ in the first $<a href="postconf.5.html#mime_boundary_length_limit">mime_boundary_length_limit</a> characters. 5773 </p> 5774 5775 <p> 5776 This feature is available in Postfix 2.0 and later. 5777 </p> 5778 5779 5780 </DD> 5781 5782 <DT><b><a name="mime_header_checks">mime_header_checks</a> 5783 (default: $<a href="postconf.5.html#header_checks">header_checks</a>)</b></DT><DD> 5784 5785 <p> 5786 Optional lookup tables for content inspection of MIME related 5787 message headers, as described in the <a href="header_checks.5.html">header_checks(5)</a> manual page. 5788 </p> 5789 5790 <p> 5791 This feature is available in Postfix 2.0 and later. 5792 </p> 5793 5794 5795 </DD> 5796 5797 <DT><b><a name="mime_nesting_limit">mime_nesting_limit</a> 5798 (default: 100)</b></DT><DD> 5799 5800 <p> 5801 The maximal recursion level that the MIME processor will handle. 5802 Postfix refuses mail that is nested deeper than the specified limit. 5803 </p> 5804 5805 <p> 5806 This feature is available in Postfix 2.0 and later. 5807 </p> 5808 5809 5810 </DD> 5811 5812 <DT><b><a name="minimal_backoff_time">minimal_backoff_time</a> 5813 (default: 300s)</b></DT><DD> 5814 5815 <p> 5816 The minimal time between attempts to deliver a deferred message; 5817 prior to Postfix 2.4 the default value was 1000s. 5818 </p> 5819 5820 <p> 5821 This parameter also limits the time an unreachable destination is 5822 kept in the short-term, in-memory, destination status cache. 5823 </p> 5824 5825 <p> This parameter should be set greater than or equal to 5826 $<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> 5827 5828 <p> 5829 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 5830 The default time unit is s (seconds). 5831 </p> 5832 5833 5834 </DD> 5835 5836 <DT><b><a name="multi_instance_directories">multi_instance_directories</a> 5837 (default: empty)</b></DT><DD> 5838 5839 <p> An optional list of non-default Postfix configuration directories; 5840 these directories belong to additional Postfix instances that share 5841 the Postfix executable files and documentation with the default 5842 Postfix instance, and that are started, stopped, etc., together 5843 with the default Postfix instance. Specify a list of pathnames 5844 separated by comma or whitespace. </p> 5845 5846 <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 5847 runs in single-instance mode and operates on a single Postfix 5848 instance only. Otherwise, the <a href="postfix.1.html">postfix(1)</a> command runs in multi-instance 5849 mode and invokes the multi-instance manager specified with the 5850 <a href="postconf.5.html#multi_instance_wrapper">multi_instance_wrapper</a> parameter. The multi-instance manager in 5851 turn executes <a href="postfix.1.html">postfix(1)</a> commands for the default instance and for 5852 all Postfix instances in $<a href="postconf.5.html#multi_instance_directories">multi_instance_directories</a>. </p> 5853 5854 <p> Currently, this parameter setting is ignored except for the 5855 default <a href="postconf.5.html">main.cf</a> file. </p> 5856 5857 <p> This feature is available in Postfix 2.6 and later. </p> 5858 5859 5860 </DD> 5861 5862 <DT><b><a name="multi_instance_enable">multi_instance_enable</a> 5863 (default: no)</b></DT><DD> 5864 5865 <p> Allow this Postfix instance to be started, stopped, etc., by a 5866 multi-instance manager. By default, new instances are created in 5867 a safe state that prevents them from being started inadvertently. 5868 This parameter is reserved for the multi-instance manager. </p> 5869 5870 <p> This feature is available in Postfix 2.6 and later. </p> 5871 5872 5873 </DD> 5874 5875 <DT><b><a name="multi_instance_group">multi_instance_group</a> 5876 (default: empty)</b></DT><DD> 5877 5878 <p> The optional instance group name of this Postfix instance. A 5879 group identifies closely-related Postfix instances that the 5880 multi-instance manager can start, stop, etc., as a unit. This 5881 parameter is reserved for the multi-instance manager. </p> 5882 5883 <p> This feature is available in Postfix 2.6 and later. </p> 5884 5885 5886 </DD> 5887 5888 <DT><b><a name="multi_instance_name">multi_instance_name</a> 5889 (default: empty)</b></DT><DD> 5890 5891 <p> The optional instance name of this Postfix instance. This name 5892 becomes also the default value for the <a href="postconf.5.html#syslog_name">syslog_name</a> parameter. </p> 5893 5894 <p> This feature is available in Postfix 2.6 and later. </p> 5895 5896 5897 </DD> 5898 5899 <DT><b><a name="multi_instance_wrapper">multi_instance_wrapper</a> 5900 (default: empty)</b></DT><DD> 5901 5902 <p> The pathname of a multi-instance manager command that the 5903 <a href="postfix.1.html">postfix(1)</a> command invokes when the <a href="postconf.5.html#multi_instance_directories">multi_instance_directories</a> 5904 parameter value is non-empty. The pathname may be followed by 5905 initial command arguments separated by whitespace; shell 5906 metacharacters such as quotes are not supported in this context. 5907 </p> 5908 5909 <p> The <a href="postfix.1.html">postfix(1)</a> command invokes the manager command with the 5910 <a href="postfix.1.html">postfix(1)</a> non-option command arguments on the manager command line, 5911 and with all installation configuration parameters exported into 5912 the manager command process environment. The manager command in 5913 turn invokes the <a href="postfix.1.html">postfix(1)</a> command for individual Postfix instances 5914 as "postfix -c <i><a href="postconf.5.html#config_directory">config_directory</a></i> <i>command</i>". </p> 5915 5916 <p> This feature is available in Postfix 2.6 and later. </p> 5917 5918 5919 </DD> 5920 5921 <DT><b><a name="multi_recipient_bounce_reject_code">multi_recipient_bounce_reject_code</a> 5922 (default: 550)</b></DT><DD> 5923 5924 <p> 5925 The numerical Postfix SMTP server response code when a remote SMTP 5926 client request is blocked by the <a href="postconf.5.html#reject_multi_recipient_bounce">reject_multi_recipient_bounce</a> 5927 restriction. 5928 </p> 5929 5930 <p> 5931 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 5932 </p> 5933 5934 <p> 5935 This feature is available in Postfix 2.1 and later. 5936 </p> 5937 5938 5939 </DD> 5940 5941 <DT><b><a name="mydestination">mydestination</a> 5942 (default: $<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a>, localhost)</b></DT><DD> 5943 5944 <p> The list of domains that are delivered via the $<a href="postconf.5.html#local_transport">local_transport</a> 5945 mail delivery transport. By default this is the Postfix <a href="local.8.html">local(8)</a> 5946 delivery agent which looks up all recipients in /etc/passwd and 5947 /etc/aliases. The SMTP server validates recipient addresses with 5948 $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> and rejects non-existent recipients. See also 5949 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. 5950 </p> 5951 5952 <p> 5953 The default <a href="postconf.5.html#mydestination">mydestination</a> value specifies names for the local 5954 machine only. On a mail domain gateway, you should also include 5955 $<a href="postconf.5.html#mydomain">mydomain</a>. 5956 </p> 5957 5958 <p> 5959 The $<a href="postconf.5.html#local_transport">local_transport</a> delivery method is also selected for mail 5960 addressed to user@[the.net.work.address] of the mail system (the 5961 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> 5962 parameters). 5963 </p> 5964 5965 <p> 5966 Warnings: 5967 </p> 5968 5969 <ul> 5970 5971 <li><p>Do not specify the names of virtual domains - those domains 5972 are specified elsewhere. See <a href="VIRTUAL_README.html">VIRTUAL_README</a> for more information. </p> 5973 5974 <li><p>Do not specify the names of domains that this machine is 5975 backup MX host for. See <a href="STANDARD_CONFIGURATION_README.html">STANDARD_CONFIGURATION_README</a> for how to 5976 set up backup MX hosts. </p> 5977 5978 <li><p>By default, the Postfix SMTP server rejects mail for recipients 5979 not listed with the <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> parameter. See the 5980 <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> 5981 and <a href="postconf.5.html#unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> parameters. </p> 5982 5983 </ul> 5984 5985 <p> 5986 Specify a list of host or domain names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" 5987 patterns, separated by commas and/or whitespace. A "/file/name" 5988 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 5989 is matched when a name matches a lookup key (the lookup result is 5990 ignored). Continue long lines by starting the next line with 5991 whitespace. </p> 5992 5993 <p> 5994 Examples: 5995 </p> 5996 5997 <pre> 5998 <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> 5999 <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> 6000 </pre> 6001 6002 6003 </DD> 6004 6005 <DT><b><a name="mydomain">mydomain</a> 6006 (default: see "postconf -d" output)</b></DT><DD> 6007 6008 <p> 6009 The internet domain name of this mail system. The default is to 6010 use $<a href="postconf.5.html#myhostname">myhostname</a> minus the first component. $<a href="postconf.5.html#mydomain">mydomain</a> is used as 6011 a default value for many other configuration parameters. 6012 </p> 6013 6014 <p> 6015 Example: 6016 </p> 6017 6018 <pre> 6019 <a href="postconf.5.html#mydomain">mydomain</a> = domain.tld 6020 </pre> 6021 6022 6023 </DD> 6024 6025 <DT><b><a name="myhostname">myhostname</a> 6026 (default: see "postconf -d" output)</b></DT><DD> 6027 6028 <p> 6029 The internet hostname of this mail system. The default is to use 6030 the fully-qualified domain name from gethostname(). $<a href="postconf.5.html#myhostname">myhostname</a> is 6031 used as a default value for many other configuration parameters. 6032 </p> 6033 6034 <p> 6035 Example: 6036 </p> 6037 6038 <pre> 6039 <a href="postconf.5.html#myhostname">myhostname</a> = host.example.com 6040 </pre> 6041 6042 6043 </DD> 6044 6045 <DT><b><a name="mynetworks">mynetworks</a> 6046 (default: see "postconf -d" output)</b></DT><DD> 6047 6048 <p> 6049 The list of "trusted" SMTP clients that have more privileges than 6050 "strangers". 6051 </p> 6052 6053 <p> 6054 In particular, "trusted" SMTP clients are allowed to relay mail 6055 through Postfix. See the <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> parameter 6056 description in the <a href="postconf.5.html">postconf(5)</a> manual. 6057 </p> 6058 6059 <p> 6060 You can specify the list of "trusted" network addresses by hand 6061 or you can let Postfix do it for you (which is the default). 6062 See the description of the <a href="postconf.5.html#mynetworks_style">mynetworks_style</a> parameter for more 6063 information. 6064 </p> 6065 6066 <p> 6067 If you specify the <a href="postconf.5.html#mynetworks">mynetworks</a> list by hand, 6068 Postfix ignores the <a href="postconf.5.html#mynetworks_style">mynetworks_style</a> setting. 6069 </p> 6070 6071 <p> Specify a list of network addresses or network/netmask patterns, 6072 separated by commas and/or whitespace. Continue long lines by 6073 starting the next line with whitespace. </p> 6074 6075 <p> The netmask specifies the number of bits in the network part 6076 of a host address. You can also specify "/file/name" or "<a href="DATABASE_README.html">type:table</a>" 6077 patterns. A "/file/name" pattern is replaced by its contents; a 6078 "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a table entry matches a 6079 lookup string (the lookup result is ignored). </p> 6080 6081 <p> The list is matched left to right, and the search stops on the 6082 first match. Specify "!pattern" to exclude an address or network 6083 block from the list. The form "!/file/name" is supported only 6084 in Postfix version 2.4 and later. </p> 6085 6086 <p> Note: IP version 6 address information must be specified inside 6087 <tt>[]</tt> in the <a href="postconf.5.html#mynetworks">mynetworks</a> value, and in files specified with 6088 "/file/name". IP version 6 addresses contain the ":" character, 6089 and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" pattern. </p> 6090 6091 <p> Examples: </p> 6092 6093 <pre> 6094 <a href="postconf.5.html#mynetworks">mynetworks</a> = 127.0.0.0/8 168.100.189.0/28 6095 <a href="postconf.5.html#mynetworks">mynetworks</a> = !192.168.0.1, 192.168.0.0/28 6096 <a href="postconf.5.html#mynetworks">mynetworks</a> = 127.0.0.0/8 168.100.189.0/28 [::1]/128 [2001:240:587::]/64 6097 <a href="postconf.5.html#mynetworks">mynetworks</a> = $<a href="postconf.5.html#config_directory">config_directory</a>/mynetworks 6098 <a href="postconf.5.html#mynetworks">mynetworks</a> = hash:/etc/postfix/network_table 6099 </pre> 6100 6101 6102 </DD> 6103 6104 <DT><b><a name="mynetworks_style">mynetworks_style</a> 6105 (default: subnet)</b></DT><DD> 6106 6107 <p> 6108 The method to generate the default value for the <a href="postconf.5.html#mynetworks">mynetworks</a> parameter. 6109 This is the list of trusted networks for relay access control etc. 6110 </p> 6111 6112 <ul> 6113 6114 <li><p>Specify "<a href="postconf.5.html#mynetworks_style">mynetworks_style</a> = host" when Postfix should 6115 "trust" only the local machine. </p> 6116 6117 <li><p>Specify "<a href="postconf.5.html#mynetworks_style">mynetworks_style</a> = subnet" when Postfix 6118 should "trust" SMTP clients in the same IP subnetworks as the local 6119 machine. On Linux, this works correctly only with interfaces 6120 specified with the "ifconfig" command. </p> 6121 6122 <li><p>Specify "<a href="postconf.5.html#mynetworks_style">mynetworks_style</a> = class" when Postfix should 6123 "trust" SMTP clients in the same IP class A/B/C networks as the 6124 local machine. Don't do this with a dialup site - it would cause 6125 Postfix to "trust" your entire provider's network. Instead, specify 6126 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> 6127 configuration parameter. </p> 6128 6129 </ul> 6130 6131 6132 </DD> 6133 6134 <DT><b><a name="myorigin">myorigin</a> 6135 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 6136 6137 <p> 6138 The domain name that locally-posted mail appears to come 6139 from, and that locally posted mail is delivered to. The default, 6140 $<a href="postconf.5.html#myhostname">myhostname</a>, is adequate for small sites. If you run a domain with 6141 multiple machines, you should (1) change this to $<a href="postconf.5.html#mydomain">mydomain</a> and (2) 6142 set up a domain-wide alias database that aliases each user to 6143 user (a] that.users.mailhost. 6144 </p> 6145 6146 <p> 6147 Example: 6148 </p> 6149 6150 <pre> 6151 <a href="postconf.5.html#myorigin">myorigin</a> = $<a href="postconf.5.html#mydomain">mydomain</a> 6152 </pre> 6153 6154 6155 </DD> 6156 6157 <DT><b><a name="nested_header_checks">nested_header_checks</a> 6158 (default: $<a href="postconf.5.html#header_checks">header_checks</a>)</b></DT><DD> 6159 6160 <p> 6161 Optional lookup tables for content inspection of non-MIME message 6162 headers in attached messages, as described in the <a href="header_checks.5.html">header_checks(5)</a> 6163 manual page. 6164 </p> 6165 6166 <p> 6167 This feature is available in Postfix 2.0 and later. 6168 </p> 6169 6170 6171 </DD> 6172 6173 <DT><b><a name="newaliases_path">newaliases_path</a> 6174 (default: see "postconf -d" output)</b></DT><DD> 6175 6176 <p> 6177 Sendmail compatibility feature that specifies the location of the 6178 <a href="newaliases.1.html">newaliases(1)</a> command. This command can be used to rebuild the 6179 <a href="local.8.html">local(8)</a> <a href="aliases.5.html">aliases(5)</a> database. 6180 </p> 6181 6182 6183 </DD> 6184 6185 <DT><b><a name="non_fqdn_reject_code">non_fqdn_reject_code</a> 6186 (default: 504)</b></DT><DD> 6187 6188 <p> 6189 The numerical Postfix SMTP server reply code when a client request 6190 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> 6191 or <a href="postconf.5.html#reject_non_fqdn_recipient">reject_non_fqdn_recipient</a> restriction. 6192 </p> 6193 6194 6195 </DD> 6196 6197 <DT><b><a name="non_smtpd_milters">non_smtpd_milters</a> 6198 (default: empty)</b></DT><DD> 6199 6200 <p> A list of Milter (mail filter) applications for new mail that 6201 does not arrive via the Postfix <a href="smtpd.8.html">smtpd(8)</a> server. This includes local 6202 submission via the <a href="sendmail.1.html">sendmail(1)</a> command line, new mail that arrives 6203 via the Postfix <a href="qmqpd.8.html">qmqpd(8)</a> server, and old mail that is re-injected 6204 into the queue with "postsuper -r". See the <a href="MILTER_README.html">MILTER_README</a> document 6205 for details. </p> 6206 6207 <p> This feature is available in Postfix 2.3 and later. </p> 6208 6209 6210 </DD> 6211 6212 <DT><b><a name="notify_classes">notify_classes</a> 6213 (default: resource, software)</b></DT><DD> 6214 6215 <p> 6216 The list of error classes that are reported to the postmaster. The 6217 default is to report only the most serious problems. The paranoid 6218 may wish to turn on the policy (UCE and mail relaying) and protocol 6219 error (broken mail software) reports. 6220 </p> 6221 6222 <p> NOTE: postmaster notifications may contain confidential information 6223 such as SASL passwords or message content. It is the system 6224 administrator's responsibility to treat such information with care. 6225 </p> 6226 6227 <p> 6228 The error classes are: 6229 </p> 6230 6231 <dl> 6232 6233 <dt><b>bounce</b> (also implies <b>2bounce</b>)</dt> 6234 6235 <dd>Send the postmaster copies of the headers of bounced mail, and 6236 send transcripts of SMTP sessions when Postfix rejects mail. The 6237 notification is sent to the address specified with the 6238 <a href="postconf.5.html#bounce_notice_recipient">bounce_notice_recipient</a> configuration parameter (default: postmaster). 6239 </dd> 6240 6241 <dt><b>2bounce</b></dt> 6242 6243 <dd>Send undeliverable bounced mail to the postmaster. The notification 6244 is sent to the address specified with the <a href="postconf.5.html#2bounce_notice_recipient">2bounce_notice_recipient</a> 6245 configuration parameter (default: postmaster). </dd> 6246 6247 <dt><b>delay</b></dt> 6248 6249 <dd>Send the postmaster copies of the headers of delayed mail. The 6250 notification is sent to the address specified with the 6251 <a href="postconf.5.html#delay_notice_recipient">delay_notice_recipient</a> configuration parameter (default: postmaster). 6252 </dd> 6253 6254 <dt><b>policy</b></dt> 6255 6256 <dd>Send the postmaster a transcript of the SMTP session when a 6257 client request was rejected because of (UCE) policy. The notification 6258 is sent to the address specified with the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> 6259 configuration parameter (default: postmaster). </dd> 6260 6261 <dt><b>protocol</b></dt> 6262 6263 <dd>Send the postmaster a transcript of the SMTP session in case 6264 of client or server protocol errors. The notification is sent to 6265 the address specified with the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> configuration 6266 parameter (default: postmaster). </dd> 6267 6268 <dt><b>resource</b></dt> 6269 6270 <dd>Inform the postmaster of mail not delivered due to resource 6271 problems. The notification is sent to the address specified with 6272 the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> configuration parameter (default: 6273 postmaster). </dd> 6274 6275 <dt><b>software</b></dt> 6276 6277 <dd>Inform the postmaster of mail not delivered due to software 6278 problems. The notification is sent to the address specified with 6279 the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> configuration parameter (default: 6280 postmaster). </dd> 6281 6282 </dl> 6283 6284 <p> 6285 Examples: 6286 </p> 6287 6288 <pre> 6289 <a href="postconf.5.html#notify_classes">notify_classes</a> = bounce, delay, policy, protocol, resource, software 6290 <a href="postconf.5.html#notify_classes">notify_classes</a> = 2bounce, resource, software 6291 </pre> 6292 6293 6294 </DD> 6295 6296 <DT><b><a name="owner_request_special">owner_request_special</a> 6297 (default: yes)</b></DT><DD> 6298 6299 <p> 6300 Give special treatment to owner-listname and listname-request 6301 address localparts: don't split such addresses when the 6302 <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> is set to "-". This feature is useful for 6303 mailing lists. 6304 </p> 6305 6306 6307 </DD> 6308 6309 <DT><b><a name="parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> 6310 (default: see "postconf -d" output)</b></DT><DD> 6311 6312 <p> 6313 What Postfix features match subdomains of "domain.tld" automatically, 6314 instead of requiring an explicit ".domain.tld" pattern. This is 6315 planned backwards compatibility: eventually, all Postfix features 6316 are expected to require explicit ".domain.tld" style patterns when 6317 you really want to match subdomains. 6318 </p> 6319 6320 6321 </DD> 6322 6323 <DT><b><a name="permit_mx_backup_networks">permit_mx_backup_networks</a> 6324 (default: empty)</b></DT><DD> 6325 6326 <p> 6327 Restrict the use of the <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> SMTP access feature to 6328 only domains whose primary MX hosts match the listed networks. 6329 The parameter value syntax is the same as with the <a href="postconf.5.html#mynetworks">mynetworks</a> 6330 parameter; note, however, that the default value is empty. </p> 6331 6332 6333 </DD> 6334 6335 <DT><b><a name="pickup_service_name">pickup_service_name</a> 6336 (default: pickup)</b></DT><DD> 6337 6338 <p> 6339 The name of the <a href="pickup.8.html">pickup(8)</a> service. This service picks up local mail 6340 submissions from the Postfix <a href="QSHAPE_README.html#maildrop_queue">maildrop queue</a>. 6341 </p> 6342 6343 <p> 6344 This feature is available in Postfix 2.0 and later. 6345 </p> 6346 6347 6348 </DD> 6349 6350 <DT><b><a name="plaintext_reject_code">plaintext_reject_code</a> 6351 (default: 450)</b></DT><DD> 6352 6353 <p> 6354 The numerical Postfix SMTP server response code when a request 6355 is rejected by the <b><a href="postconf.5.html#reject_plaintext_session">reject_plaintext_session</a></b> restriction. 6356 </p> 6357 6358 <p> This feature is available in Postfix 2.3 and later. </p> 6359 6360 6361 </DD> 6362 6363 <DT><b><a name="postmulti_control_commands">postmulti_control_commands</a> 6364 (default: reload flush)</b></DT><DD> 6365 6366 <p> The <a href="postfix.1.html">postfix(1)</a> commands that the <a href="postmulti.1.html">postmulti(1)</a> instance manager 6367 treats as "control" commands, that operate on running instances. For 6368 these commands, disabled instances are skipped. </p> 6369 6370 <p> This feature is available in Postfix 2.6 and later. </p> 6371 6372 6373 </DD> 6374 6375 <DT><b><a name="postmulti_start_commands">postmulti_start_commands</a> 6376 (default: start)</b></DT><DD> 6377 6378 <p> The <a href="postfix.1.html">postfix(1)</a> commands that the <a href="postmulti.1.html">postmulti(1)</a> instance manager treats 6379 as "start" commands. For these commands, disabled instances are "checked" 6380 rather than "started", and failure to "start" a member instance of an 6381 instance group will abort the start-up of later instances. </p> 6382 6383 <p> This feature is available in Postfix 2.6 and later. </p> 6384 6385 6386 </DD> 6387 6388 <DT><b><a name="postmulti_stop_commands">postmulti_stop_commands</a> 6389 (default: see "postconf -d" output)</b></DT><DD> 6390 6391 <p> The <a href="postfix.1.html">postfix(1)</a> commands that the <a href="postmulti.1.html">postmulti(1)</a> instance manager treats 6392 as "stop" commands. For these commands, disabled instances are skipped, 6393 and enabled instances are processed in reverse order. </p> 6394 6395 <p> This feature is available in Postfix 2.6 and later. </p> 6396 6397 6398 </DD> 6399 6400 <DT><b><a name="prepend_delivered_header">prepend_delivered_header</a> 6401 (default: command, file, forward)</b></DT><DD> 6402 6403 <p> The message delivery contexts where the Postfix <a href="local.8.html">local(8)</a> delivery 6404 agent prepends a Delivered-To: message header with the address 6405 that the mail was delivered to. This information is used for mail 6406 delivery loop detection. </p> 6407 6408 <p> 6409 By default, the Postfix local delivery agent prepends a Delivered-To: 6410 header when forwarding mail and when delivering to file (mailbox) 6411 and command. Turning off the Delivered-To: header when forwarding 6412 mail is not recommended. 6413 </p> 6414 6415 <p> 6416 Specify zero or more of <b>forward</b>, <b>file</b>, or <b>command</b>. 6417 </p> 6418 6419 <p> 6420 Example: 6421 </p> 6422 6423 <pre> 6424 <a href="postconf.5.html#prepend_delivered_header">prepend_delivered_header</a> = forward 6425 </pre> 6426 6427 6428 </DD> 6429 6430 <DT><b><a name="process_id">process_id</a> 6431 (read-only)</b></DT><DD> 6432 6433 <p> 6434 The process ID of a Postfix command or daemon process. 6435 </p> 6436 6437 6438 </DD> 6439 6440 <DT><b><a name="process_id_directory">process_id_directory</a> 6441 (default: pid)</b></DT><DD> 6442 6443 <p> 6444 The location of Postfix PID files relative to $<a href="postconf.5.html#queue_directory">queue_directory</a>. 6445 This is a read-only parameter. 6446 </p> 6447 6448 6449 </DD> 6450 6451 <DT><b><a name="process_name">process_name</a> 6452 (read-only)</b></DT><DD> 6453 6454 <p> 6455 The process name of a Postfix command or daemon process. 6456 </p> 6457 6458 6459 </DD> 6460 6461 <DT><b><a name="propagate_unmatched_extensions">propagate_unmatched_extensions</a> 6462 (default: canonical, virtual)</b></DT><DD> 6463 6464 <p> 6465 What address lookup tables copy an address extension from the lookup 6466 key to the lookup result. 6467 </p> 6468 6469 <p> 6470 For example, with a <a href="virtual.5.html">virtual(5)</a> mapping of "<i>joe (a] example.com => 6471 joe.user (a] example.net</i>", the address "<i>joe+foo (a] example.com</i>" 6472 would rewrite to "<i>joe.user+foo (a] example.net</i>". 6473 </p> 6474 6475 <p> 6476 Specify zero or more of <b>canonical</b>, <b>virtual</b>, <b>alias</b>, 6477 <b>forward</b>, <b>include</b> or <b>generic</b>. These cause 6478 address extension 6479 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, 6480 with <a href="local.8.html">local(8)</a> .forward and :include: file lookups, and with <a href="smtp.8.html">smtp(8)</a> 6481 generic maps, respectively. </p> 6482 6483 <p> 6484 Note: enabling this feature for types other than <b>canonical</b> 6485 and <b>virtual</b> is likely to cause problems when mail is forwarded 6486 to other sites, especially with mail that is sent to a mailing list 6487 exploder address. 6488 </p> 6489 6490 <p> 6491 Examples: 6492 </p> 6493 6494 <pre> 6495 <a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> = canonical, virtual, alias, 6496 forward, include 6497 <a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> = canonical, virtual 6498 </pre> 6499 6500 6501 </DD> 6502 6503 <DT><b><a name="proxy_interfaces">proxy_interfaces</a> 6504 (default: empty)</b></DT><DD> 6505 6506 <p> 6507 The network interface addresses that this mail system receives mail 6508 on by way of a proxy or network address translation unit. 6509 </p> 6510 6511 <p> 6512 This feature is available in Postfix 2.0 and later. 6513 </p> 6514 6515 <p> You must specify your "outside" proxy/NAT addresses when your 6516 system is a backup MX host for other domains, otherwise mail delivery 6517 loops will happen when the primary MX host is down. </p> 6518 6519 <p> 6520 Example: 6521 </p> 6522 6523 <pre> 6524 <a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> = 1.2.3.4 6525 </pre> 6526 6527 6528 </DD> 6529 6530 <DT><b><a name="proxy_read_maps">proxy_read_maps</a> 6531 (default: see "postconf -d" output)</b></DT><DD> 6532 6533 <p> 6534 The lookup tables that the <a href="proxymap.8.html">proxymap(8)</a> server is allowed to 6535 access for the read-only service. 6536 Table references that don't begin with <a href="proxymap.8.html">proxy</a>: are ignored. 6537 </p> 6538 6539 <p> 6540 This feature is available in Postfix 2.0 and later. 6541 </p> 6542 6543 6544 </DD> 6545 6546 <DT><b><a name="proxy_write_maps">proxy_write_maps</a> 6547 (default: see "postconf -d" output)</b></DT><DD> 6548 6549 <p> The lookup tables that the <a href="proxymap.8.html">proxymap(8)</a> server is allowed to 6550 access for the read-write service. Postfix-owned local database 6551 files should be stored under the Postfix-owned <a href="postconf.5.html#data_directory">data_directory</a>. 6552 Table references that don't begin with <a href="proxymap.8.html">proxy</a>: are ignored. </p> 6553 6554 <p> 6555 This feature is available in Postfix 2.5 and later. 6556 </p> 6557 6558 6559 </DD> 6560 6561 <DT><b><a name="proxymap_service_name">proxymap_service_name</a> 6562 (default: proxymap)</b></DT><DD> 6563 6564 <p> The name of the proxymap read-only table lookup service. This 6565 service is normally implemented by the <a href="proxymap.8.html">proxymap(8)</a> daemon. </p> 6566 6567 <p> This feature is available in Postfix 2.6 and later. </p> 6568 6569 6570 </DD> 6571 6572 <DT><b><a name="proxywrite_service_name">proxywrite_service_name</a> 6573 (default: proxywrite)</b></DT><DD> 6574 6575 <p> The name of the proxywrite read-write table lookup service. 6576 This service is normally implemented by the <a href="proxymap.8.html">proxymap(8)</a> daemon. 6577 </p> 6578 6579 <p> This feature is available in Postfix 2.6 and later. </p> 6580 6581 6582 </DD> 6583 6584 <DT><b><a name="qmgr_clog_warn_time">qmgr_clog_warn_time</a> 6585 (default: 300s)</b></DT><DD> 6586 6587 <p> 6588 The minimal delay between warnings that a specific destination is 6589 clogging up the Postfix <a href="QSHAPE_README.html#active_queue">active queue</a>. Specify 0 to disable. 6590 </p> 6591 6592 <p> 6593 This feature is enabled with the <a href="postconf.5.html#helpful_warnings">helpful_warnings</a> parameter. 6594 </p> 6595 6596 <p> 6597 This feature is available in Postfix 2.0 and later. 6598 </p> 6599 6600 6601 </DD> 6602 6603 <DT><b><a name="qmgr_fudge_factor">qmgr_fudge_factor</a> 6604 (default: 100)</b></DT><DD> 6605 6606 <p> 6607 Obsolete feature: the percentage of delivery resources that a busy 6608 mail system will use up for delivery of a large mailing list 6609 message. 6610 </p> 6611 6612 <p> 6613 This feature exists only in the <a href="qmgr.8.html">oqmgr(8)</a> old queue manager. The 6614 current queue manager solves the problem in a better way. 6615 </p> 6616 6617 6618 </DD> 6619 6620 <DT><b><a name="qmgr_message_active_limit">qmgr_message_active_limit</a> 6621 (default: 20000)</b></DT><DD> 6622 6623 <p> 6624 The maximal number of messages in the <a href="QSHAPE_README.html#active_queue">active queue</a>. 6625 </p> 6626 6627 6628 </DD> 6629 6630 <DT><b><a name="qmgr_message_recipient_limit">qmgr_message_recipient_limit</a> 6631 (default: 20000)</b></DT><DD> 6632 6633 <p> The maximal number of recipients held in memory by the Postfix 6634 queue manager, and the maximal size of the size of the short-term, 6635 in-memory "dead" destination status cache. </p> 6636 6637 6638 </DD> 6639 6640 <DT><b><a name="qmgr_message_recipient_minimum">qmgr_message_recipient_minimum</a> 6641 (default: 10)</b></DT><DD> 6642 6643 <p> 6644 The minimal number of in-memory recipients for any message. This 6645 takes priority over any other in-memory recipient limits (i.e., 6646 the global <a href="postconf.5.html#qmgr_message_recipient_limit">qmgr_message_recipient_limit</a> and the per transport 6647 _recipient_limit) if necessary. The minimum value allowed for this 6648 parameter is 1. 6649 </p> 6650 6651 6652 </DD> 6653 6654 <DT><b><a name="qmqpd_authorized_clients">qmqpd_authorized_clients</a> 6655 (default: empty)</b></DT><DD> 6656 6657 <p> 6658 What clients are allowed to connect to the QMQP server port. 6659 </p> 6660 6661 <p> 6662 By default, no client is allowed to use the service. This is 6663 because the QMQP server will relay mail to any destination. 6664 </p> 6665 6666 <p> 6667 Specify a list of client patterns. A list pattern specifies a host 6668 name, a domain name, an internet address, or a network/mask pattern, 6669 where the mask specifies the number of bits in the network part. 6670 When a pattern specifies a file name, its contents are substituted 6671 for the file name; when a pattern is a "<a href="DATABASE_README.html">type:table</a>" table specification, 6672 table lookup is used instead. </p> 6673 6674 <p> 6675 Patterns are separated by whitespace and/or commas. In order to 6676 reverse the result, precede a pattern with an 6677 exclamation point (!). The form "!/file/name" is supported only 6678 in Postfix version 2.4 and later. 6679 </p> 6680 6681 <p> 6682 Example: 6683 </p> 6684 6685 <pre> 6686 <a href="postconf.5.html#qmqpd_authorized_clients">qmqpd_authorized_clients</a> = !192.168.0.1, 192.168.0.0/24 6687 </pre> 6688 6689 6690 </DD> 6691 6692 <DT><b><a name="qmqpd_client_port_logging">qmqpd_client_port_logging</a> 6693 (default: no)</b></DT><DD> 6694 6695 <p> Enable logging of the remote QMQP client port in addition to 6696 the hostname and IP address. The logging format is "host[address]:port". 6697 </p> 6698 6699 <p> This feature is available in Postfix 2.5 and later. </p> 6700 6701 6702 </DD> 6703 6704 <DT><b><a name="qmqpd_error_delay">qmqpd_error_delay</a> 6705 (default: 1s)</b></DT><DD> 6706 6707 <p> 6708 How long the QMQP server will pause before sending a negative reply 6709 to the client. The purpose is to slow down confused or malicious 6710 clients. 6711 </p> 6712 6713 <p> 6714 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 6715 The default time unit is s (seconds). 6716 </p> 6717 6718 6719 </DD> 6720 6721 <DT><b><a name="qmqpd_timeout">qmqpd_timeout</a> 6722 (default: 300s)</b></DT><DD> 6723 6724 <p> 6725 The time limit for sending or receiving information over the network. 6726 If a read or write operation blocks for more than $<a href="postconf.5.html#qmqpd_timeout">qmqpd_timeout</a> 6727 seconds the QMQP server gives up and disconnects. 6728 </p> 6729 6730 <p> 6731 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 6732 The default time unit is s (seconds). 6733 </p> 6734 6735 6736 </DD> 6737 6738 <DT><b><a name="queue_directory">queue_directory</a> 6739 (default: see "postconf -d" output)</b></DT><DD> 6740 6741 <p> 6742 The location of the Postfix top-level queue directory. This is the 6743 root directory of Postfix daemon processes that run chrooted. 6744 </p> 6745 6746 6747 </DD> 6748 6749 <DT><b><a name="queue_file_attribute_count_limit">queue_file_attribute_count_limit</a> 6750 (default: 100)</b></DT><DD> 6751 6752 <p> 6753 The maximal number of (name=value) attributes that may be stored 6754 in a Postfix queue file. The limit is enforced by the <a href="cleanup.8.html">cleanup(8)</a> 6755 server. 6756 </p> 6757 6758 <p> 6759 This feature is available in Postfix 2.0 and later. 6760 </p> 6761 6762 6763 </DD> 6764 6765 <DT><b><a name="queue_minfree">queue_minfree</a> 6766 (default: 0)</b></DT><DD> 6767 6768 <p> 6769 The minimal amount of free space in bytes in the queue file system 6770 that is needed to receive mail. This is currently used by the SMTP 6771 server to decide if it will accept any mail at all. 6772 </p> 6773 6774 <p> 6775 By default, the Postfix version 2.1 SMTP server rejects MAIL FROM commands 6776 when the amount of free space is less than 1.5*$<a href="postconf.5.html#message_size_limit">message_size_limit</a>. 6777 To specify a higher minimum free space limit, specify a <a href="postconf.5.html#queue_minfree">queue_minfree</a> 6778 value that is at least 1.5*$<a href="postconf.5.html#message_size_limit">message_size_limit</a>. 6779 </p> 6780 6781 <p> 6782 With Postfix versions 2.0 and earlier, a <a href="postconf.5.html#queue_minfree">queue_minfree</a> value of 6783 zero means there is no minimum required amount of free space. 6784 </p> 6785 6786 6787 </DD> 6788 6789 <DT><b><a name="queue_run_delay">queue_run_delay</a> 6790 (default: 300s)</b></DT><DD> 6791 6792 <p> 6793 The time between <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> scans by the queue manager; 6794 prior to Postfix 2.4 the default value was 1000s. 6795 </p> 6796 6797 <p> This parameter should be set less than or equal to 6798 $<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> 6799 6800 <p> 6801 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 6802 The default time unit is s (seconds). 6803 </p> 6804 6805 6806 </DD> 6807 6808 <DT><b><a name="queue_service_name">queue_service_name</a> 6809 (default: qmgr)</b></DT><DD> 6810 6811 <p> 6812 The name of the <a href="qmgr.8.html">qmgr(8)</a> service. This service manages the Postfix 6813 queue and schedules delivery requests. 6814 </p> 6815 6816 <p> 6817 This feature is available in Postfix 2.0 and later. 6818 </p> 6819 6820 6821 </DD> 6822 6823 <DT><b><a name="rbl_reply_maps">rbl_reply_maps</a> 6824 (default: empty)</b></DT><DD> 6825 6826 <p> 6827 Optional lookup tables with RBL response templates. The tables are 6828 indexed by the RBL domain name. By default, Postfix uses the default 6829 template as specified with the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> configuration 6830 parameter. See there for a discussion of the syntax of RBL reply 6831 templates. 6832 </p> 6833 6834 <p> 6835 This feature is available in Postfix 2.0 and later. 6836 </p> 6837 6838 6839 </DD> 6840 6841 <DT><b><a name="readme_directory">readme_directory</a> 6842 (default: see "postconf -d" output)</b></DT><DD> 6843 6844 <p> 6845 The location of Postfix README files that describe how to build, 6846 configure or operate a specific Postfix subsystem or feature. 6847 </p> 6848 6849 6850 </DD> 6851 6852 <DT><b><a name="receive_override_options">receive_override_options</a> 6853 (default: empty)</b></DT><DD> 6854 6855 <p> Enable or disable recipient validation, built-in content 6856 filtering, or address mapping. Typically, these are specified in 6857 <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 6858 <a href="pickup.8.html">pickup(8)</a> daemons. </p> 6859 6860 <p> Specify zero or more of the following options. The options 6861 override <a href="postconf.5.html">main.cf</a> settings and are either implemented by <a href="smtpd.8.html">smtpd(8)</a>, 6862 <a href="qmqpd.8.html">qmqpd(8)</a>, or <a href="pickup.8.html">pickup(8)</a> themselves, or they are forwarded to the 6863 cleanup server. </p> 6864 6865 <dl> 6866 6867 <dt><b><a name="no_unknown_recipient_checks">no_unknown_recipient_checks</a></b></dt> 6868 6869 <dd>Do not try to reject unknown recipients (SMTP server only). 6870 This is typically specified AFTER an external content filter. 6871 </dd> 6872 6873 <dt><b><a name="no_address_mappings">no_address_mappings</a></b></dt> 6874 6875 <dd>Disable canonical address mapping, virtual alias map expansion, 6876 address masquerading, and automatic BCC (blind carbon-copy) 6877 recipients. This is typically specified BEFORE an external content 6878 filter. </dd> 6879 6880 <dt><b><a name="no_header_body_checks">no_header_body_checks</a></b></dt> 6881 6882 <dd>Disable header/body_checks. This is typically specified AFTER 6883 an external content filter. </dd> 6884 6885 <dt><b><a name="no_milters">no_milters</a></b></dt> 6886 6887 <dd>Disable Milter (mail filter) applications. This is typically 6888 specified AFTER an external content filter. </dd> 6889 6890 </dl> 6891 6892 <p> 6893 Note: when the "BEFORE content filter" <a href="postconf.5.html#receive_override_options">receive_override_options</a> 6894 setting is specified in the <a href="postconf.5.html">main.cf</a> file, specify the "AFTER content 6895 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 6896 versa). 6897 </p> 6898 6899 <p> 6900 Examples: 6901 </p> 6902 6903 <pre> 6904 <a href="postconf.5.html#receive_override_options">receive_override_options</a> = 6905 <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> 6906 <a href="postconf.5.html#receive_override_options">receive_override_options</a> = <a href="postconf.5.html#no_address_mappings">no_address_mappings</a> 6907 </pre> 6908 6909 <p> 6910 This feature is available in Postfix 2.1 and later. 6911 </p> 6912 6913 6914 </DD> 6915 6916 <DT><b><a name="recipient_bcc_maps">recipient_bcc_maps</a> 6917 (default: empty)</b></DT><DD> 6918 6919 <p> 6920 Optional BCC (blind carbon-copy) address lookup tables, indexed by 6921 recipient address. The BCC address (multiple results are not 6922 supported) is added when mail enters from outside of Postfix. 6923 </p> 6924 6925 <p> 6926 This feature is available in Postfix 2.1 and later. 6927 </p> 6928 6929 <p> 6930 The table search order is as follows: 6931 </p> 6932 6933 <ul> 6934 6935 <li> Look up the "user+extension (a] domain.tld" address including the 6936 optional address extension. 6937 6938 <li> Look up the "user (a] domain.tld" address without the optional 6939 address extension. 6940 6941 <li> Look up the "user+extension" address local part when the 6942 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> 6943 or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. 6944 6945 <li> Look up the "user" address local part when the recipient domain 6946 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>. 6947 6948 <li> Look up the "@domain.tld" part. 6949 6950 </ul> 6951 6952 <p> 6953 Specify the types and names of databases to use. After change, 6954 run "<b>postmap /etc/postfix/recipient_bcc</b>". 6955 </p> 6956 6957 <p> 6958 Note: if mail to the BCC address bounces it will be returned to 6959 the sender. 6960 </p> 6961 6962 <p> Note: automatic BCC recipients are produced only for new mail. 6963 To avoid mailer loops, automatic BCC recipients are not generated 6964 for mail that Postfix forwards internally, nor for mail that Postfix 6965 generates itself. </p> 6966 6967 <p> 6968 Example: 6969 </p> 6970 6971 <pre> 6972 <a href="postconf.5.html#recipient_bcc_maps">recipient_bcc_maps</a> = hash:/etc/postfix/recipient_bcc 6973 </pre> 6974 6975 6976 </DD> 6977 6978 <DT><b><a name="recipient_canonical_classes">recipient_canonical_classes</a> 6979 (default: envelope_recipient, header_recipient)</b></DT><DD> 6980 6981 <p> What addresses are subject to <a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> address 6982 mapping. By default, <a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> address mapping is 6983 applied to envelope recipient addresses, and to header recipient 6984 addresses. </p> 6985 6986 <p> Specify one or more of: envelope_recipient, header_recipient 6987 </p> 6988 6989 <p> This feature is available in Postfix 2.2 and later. </p> 6990 6991 6992 </DD> 6993 6994 <DT><b><a name="recipient_canonical_maps">recipient_canonical_maps</a> 6995 (default: empty)</b></DT><DD> 6996 6997 <p> 6998 Optional address mapping lookup tables for envelope and header 6999 recipient addresses. 7000 The table format and lookups are documented in <a href="canonical.5.html">canonical(5)</a>. 7001 </p> 7002 7003 <p> 7004 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>. 7005 </p> 7006 7007 <p> 7008 Example: 7009 </p> 7010 7011 <pre> 7012 <a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> = hash:/etc/postfix/recipient_canonical 7013 </pre> 7014 7015 7016 </DD> 7017 7018 <DT><b><a name="recipient_delimiter">recipient_delimiter</a> 7019 (default: empty)</b></DT><DD> 7020 7021 <p> 7022 The separator between user names and address extensions (user+foo). 7023 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 7024 effects this has on aliases, canonical, virtual, relocated and 7025 on .forward file lookups. Basically, the software tries user+foo 7026 and .forward+foo before trying user and .forward. 7027 </p> 7028 7029 <p> 7030 Example: 7031 </p> 7032 7033 <pre> 7034 <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> = + 7035 </pre> 7036 7037 7038 </DD> 7039 7040 <DT><b><a name="reject_code">reject_code</a> 7041 (default: 554)</b></DT><DD> 7042 7043 <p> 7044 The numerical Postfix SMTP server response code when a remote SMTP 7045 client request is rejected by the "reject" restriction. 7046 </p> 7047 7048 <p> 7049 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 7050 </p> 7051 7052 7053 </DD> 7054 7055 <DT><b><a name="reject_tempfail_action">reject_tempfail_action</a> 7056 (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>)</b></DT><DD> 7057 7058 <p> The Postfix SMTP server's action when a reject-type restriction 7059 fails due to a temporary error condition. Specify "defer" to defer 7060 the remote SMTP client request immediately. With the default 7061 "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look 7062 for opportunities to reject mail, and defers the client request 7063 only if it would otherwise be accepted. </p> 7064 7065 <p> For finer control, see: <a href="postconf.5.html#unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a>, 7066 <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>, 7067 and <a href="postconf.5.html#unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a>. </p> 7068 7069 <p> This feature is available in Postfix 2.6 and later. </p> 7070 7071 7072 </DD> 7073 7074 <DT><b><a name="relay_clientcerts">relay_clientcerts</a> 7075 (default: empty)</b></DT><DD> 7076 7077 <p> List of tables with remote SMTP client-certificate fingerprints 7078 for which the Postfix SMTP server will allow access with the 7079 <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> feature. 7080 The fingerprint digest algorithm is configurable via the 7081 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to 7082 Postfix version 2.5). </p> 7083 7084 <p> Postfix lookup tables are in the form of (key, value) pairs. 7085 Since we only need the key, the value can be chosen freely, e.g. 7086 the name of the user or host: 7087 D7:04:2F:A7:0B:8C:A5:21:FA:31:77:E1:41:8A:EE:80 lutzpc.at.home </p> 7088 7089 <p> Example: </p> 7090 7091 <pre> 7092 <a href="postconf.5.html#relay_clientcerts">relay_clientcerts</a> = hash:/etc/postfix/relay_clientcerts 7093 </pre> 7094 7095 <p>For more fine-grained control, use <a href="postconf.5.html#check_ccert_access">check_ccert_access</a> to select 7096 an appropriate <a href="access.5.html">access(5)</a> policy for each client. 7097 See <a href="RESTRICTION_CLASS_README.html">RESTRICTION_CLASS_README</a>.</p> 7098 7099 <p>This feature is available with Postfix version 2.2.</p> 7100 7101 7102 </DD> 7103 7104 <DT><b><a name="relay_destination_concurrency_limit">relay_destination_concurrency_limit</a> 7105 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 7106 7107 <p> The maximal number of parallel deliveries to the same destination 7108 via the relay message delivery transport. This limit is enforced 7109 by the queue manager. The message delivery transport name is the 7110 first field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 7111 7112 <p> This feature is available in Postfix 2.0 and later. </p> 7113 7114 7115 </DD> 7116 7117 <DT><b><a name="relay_destination_recipient_limit">relay_destination_recipient_limit</a> 7118 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 7119 7120 <p> The maximal number of recipients per message for the relay 7121 message delivery transport. This limit is enforced by the queue 7122 manager. The message delivery transport name is the first field in 7123 the entry in the <a href="master.5.html">master.cf</a> file. </p> 7124 7125 <p> Setting this parameter to a value of 1 changes the meaning of 7126 <a href="postconf.5.html#relay_destination_concurrency_limit">relay_destination_concurrency_limit</a> from concurrency per domain 7127 into concurrency per recipient. </p> 7128 7129 <p> This feature is available in Postfix 2.0 and later. </p> 7130 7131 7132 </DD> 7133 7134 <DT><b><a name="relay_domains">relay_domains</a> 7135 (default: $<a href="postconf.5.html#mydestination">mydestination</a>)</b></DT><DD> 7136 7137 <p> What destination domains (and subdomains thereof) this system 7138 will relay mail to. Subdomain matching is controlled with the 7139 <a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> parameter. For details about how 7140 the <a href="postconf.5.html#relay_domains">relay_domains</a> value is used, see the description of the 7141 <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 7142 restrictions. </p> 7143 7144 <p> Domains that match $<a href="postconf.5.html#relay_domains">relay_domains</a> are delivered with the 7145 $<a href="postconf.5.html#relay_transport">relay_transport</a> mail delivery transport. The SMTP server validates 7146 recipient addresses with $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> and rejects non-existent 7147 recipients. See also the <a href="ADDRESS_CLASS_README.html#relay_domain_class">relay domains</a> address class in the 7148 <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file. </p> 7149 7150 <p> Note: Postfix will not automatically forward mail for domains 7151 that list this system as their primary or backup MX host. See the 7152 <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> 7153 7154 <p> Specify a list of host or domain names, "/file/name" patterns 7155 or "<a href="DATABASE_README.html">type:table</a>" lookup tables, separated by commas and/or whitespace. 7156 Continue long lines by starting the next line with whitespace. A 7157 "/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" 7158 lookup table is matched when a (parent) domain appears as lookup 7159 key. Specify "!pattern" to exclude a domain from the list. The form 7160 "!/file/name" is supported only in Postfix version 2.4 and later. 7161 </p> 7162 7163 7164 </DD> 7165 7166 <DT><b><a name="relay_domains_reject_code">relay_domains_reject_code</a> 7167 (default: 554)</b></DT><DD> 7168 7169 <p> 7170 The numerical Postfix SMTP server response code when a client 7171 request is rejected by the <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> recipient 7172 restriction. 7173 </p> 7174 7175 <p> 7176 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 7177 </p> 7178 7179 7180 </DD> 7181 7182 <DT><b><a name="relay_recipient_maps">relay_recipient_maps</a> 7183 (default: empty)</b></DT><DD> 7184 7185 <p> Optional lookup tables with all valid addresses in the domains 7186 that match $<a href="postconf.5.html#relay_domains">relay_domains</a>. Specify @domain as a wild-card for 7187 domains that have no valid recipient list, and become a source of 7188 backscatter mail: Postfix accepts spam for non-existent recipients 7189 and then floods innocent people with undeliverable mail. Technically, 7190 tables 7191 listed with $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> are used as lists: Postfix needs 7192 to know only if a lookup string is found or not, but it does not 7193 use the result from table lookup. </p> 7194 7195 <p> 7196 If this parameter is non-empty, then the Postfix SMTP server will reject 7197 mail to unknown relay users. This feature is off by default. 7198 </p> 7199 7200 <p> 7201 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> 7202 file. 7203 </p> 7204 7205 <p> 7206 Example: 7207 </p> 7208 7209 <pre> 7210 <a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> = hash:/etc/postfix/relay_recipients 7211 </pre> 7212 7213 <p> 7214 This feature is available in Postfix 2.0 and later. 7215 </p> 7216 7217 7218 </DD> 7219 7220 <DT><b><a name="relay_transport">relay_transport</a> 7221 (default: relay)</b></DT><DD> 7222 7223 <p> 7224 The default mail delivery transport and next-hop destination for 7225 remote delivery to domains listed with $<a href="postconf.5.html#relay_domains">relay_domains</a>. In order of 7226 decreasing precedence, the nexthop destination is taken from 7227 $<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 7228 from the recipient domain. This information can be overruled with 7229 the <a href="transport.5.html">transport(5)</a> table. 7230 </p> 7231 7232 <p> 7233 Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i> 7234 is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>. 7235 The <i>:nexthop</i> part is optional. For more details see the 7236 <a href="transport.5.html">transport(5)</a> manual page. 7237 </p> 7238 7239 <p> 7240 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> 7241 file. 7242 </p> 7243 7244 <p> 7245 This feature is available in Postfix 2.0 and later. 7246 </p> 7247 7248 7249 </DD> 7250 7251 <DT><b><a name="relayhost">relayhost</a> 7252 (default: empty)</b></DT><DD> 7253 7254 <p> 7255 The next-hop destination of non-local mail; overrides non-local 7256 domains in recipient addresses. This information is overruled with 7257 <a href="postconf.5.html#relay_transport">relay_transport</a>, <a href="postconf.5.html#default_transport">default_transport</a>, <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> 7258 and with the <a href="transport.5.html">transport(5)</a> table. 7259 </p> 7260 7261 <p> 7262 On an intranet, specify the organizational domain name. If your 7263 internal DNS uses no MX records, specify the name of the intranet 7264 gateway host instead. 7265 </p> 7266 7267 <p> 7268 In the case of SMTP, specify a domain name, hostname, hostname:port, 7269 [hostname]:port, [hostaddress] or [hostaddress]:port. The form 7270 [hostname] turns off MX lookups. 7271 </p> 7272 7273 <p> 7274 If you're connected via UUCP, see the <a href="UUCP_README.html">UUCP_README</a> file for useful 7275 information. 7276 </p> 7277 7278 <p> 7279 Examples: 7280 </p> 7281 7282 <pre> 7283 <a href="postconf.5.html#relayhost">relayhost</a> = $<a href="postconf.5.html#mydomain">mydomain</a> 7284 <a href="postconf.5.html#relayhost">relayhost</a> = [gateway.example.com] 7285 <a href="postconf.5.html#relayhost">relayhost</a> = uucphost 7286 <a href="postconf.5.html#relayhost">relayhost</a> = [an.ip.add.ress] 7287 </pre> 7288 7289 7290 </DD> 7291 7292 <DT><b><a name="relocated_maps">relocated_maps</a> 7293 (default: empty)</b></DT><DD> 7294 7295 <p> 7296 Optional lookup tables with new contact information for users or 7297 domains that no longer exist. The table format and lookups are 7298 documented in <a href="relocated.5.html">relocated(5)</a>. 7299 </p> 7300 7301 <p> 7302 If you use this feature, run "<b>postmap /etc/postfix/relocated</b>" to 7303 build the necessary DBM or DB file after change, then "<b>postfix 7304 reload</b>" to make the changes visible. 7305 </p> 7306 7307 <p> 7308 Examples: 7309 </p> 7310 7311 <pre> 7312 <a href="postconf.5.html#relocated_maps">relocated_maps</a> = dbm:/etc/postfix/relocated 7313 <a href="postconf.5.html#relocated_maps">relocated_maps</a> = hash:/etc/postfix/relocated 7314 </pre> 7315 7316 7317 </DD> 7318 7319 <DT><b><a name="remote_header_rewrite_domain">remote_header_rewrite_domain</a> 7320 (default: empty)</b></DT><DD> 7321 7322 <p> Don't rewrite message headers from remote clients at all when 7323 this parameter is empty; otherwise, rewrite message headers and 7324 append the specified domain name to incomplete addresses. The 7325 <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> parameter controls what clients Postfix 7326 considers local. </p> 7327 7328 <p> Examples: </p> 7329 7330 <p> The safe setting: append "domain.invalid" to incomplete header 7331 addresses from remote SMTP clients, so that those addresses cannot 7332 be confused with local addresses. </p> 7333 7334 <blockquote> 7335 <pre> 7336 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> = domain.invalid 7337 </pre> 7338 </blockquote> 7339 7340 <p> The default, purist, setting: don't rewrite headers from remote 7341 clients at all. </p> 7342 7343 <blockquote> 7344 <pre> 7345 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> = 7346 </pre> 7347 </blockquote> 7348 7349 7350 </DD> 7351 7352 <DT><b><a name="require_home_directory">require_home_directory</a> 7353 (default: no)</b></DT><DD> 7354 7355 <p> 7356 Whether or not a <a href="local.8.html">local(8)</a> recipient's home directory must exist 7357 before mail delivery is attempted. By default this test is disabled. 7358 It can be useful for environments that import home directories to 7359 the mail server (NOT RECOMMENDED). 7360 </p> 7361 7362 7363 </DD> 7364 7365 <DT><b><a name="resolve_dequoted_address">resolve_dequoted_address</a> 7366 (default: yes)</b></DT><DD> 7367 7368 <p> Resolve a recipient address safely instead of correctly, by 7369 looking inside quotes. </p> 7370 7371 <p> By default, the Postfix address resolver does not quote the 7372 address localpart as per <a href="http://tools.ietf.org/html/rfc822">RFC 822</a>, so that additional @ or % or ! 7373 operators remain visible. This behavior is safe but it is also 7374 technically incorrect. </p> 7375 7376 <p> If you specify "<a href="postconf.5.html#resolve_dequoted_address">resolve_dequoted_address</a> = no", then 7377 the Postfix 7378 resolver will not know about additional @ etc. operators in the 7379 address localpart. This opens opportunities for obscure mail relay 7380 attacks with user@domain@domain addresses when Postfix provides 7381 backup MX service for Sendmail systems. </p> 7382 7383 7384 </DD> 7385 7386 <DT><b><a name="resolve_null_domain">resolve_null_domain</a> 7387 (default: no)</b></DT><DD> 7388 7389 <p> Resolve an address that ends in the "@" null domain as if the 7390 local hostname were specified, instead of rejecting the address as 7391 invalid. </p> 7392 7393 <p> This feature is available in Postfix 2.1 and later. 7394 Earlier versions always resolve the null domain as the local 7395 hostname. </p> 7396 7397 <p> The Postfix SMTP server uses this feature to reject mail from 7398 or to addresses that end in the "@" null domain, and from addresses 7399 that rewrite into a form that ends in the "@" null domain. </p> 7400 7401 7402 </DD> 7403 7404 <DT><b><a name="resolve_numeric_domain">resolve_numeric_domain</a> 7405 (default: no)</b></DT><DD> 7406 7407 <p> Resolve "user@ipaddress" as "user@[ipaddress]", instead of 7408 rejecting the address as invalid. </p> 7409 7410 <p> This feature is available in Postfix 2.3 and later. 7411 7412 7413 </DD> 7414 7415 <DT><b><a name="rewrite_service_name">rewrite_service_name</a> 7416 (default: rewrite)</b></DT><DD> 7417 7418 <p> 7419 The name of the address rewriting service. This service rewrites 7420 addresses to standard form and resolves them to a (delivery method, 7421 next-hop host, recipient) triple. 7422 </p> 7423 7424 <p> 7425 This feature is available in Postfix 2.0 and later. 7426 </p> 7427 7428 7429 </DD> 7430 7431 <DT><b><a name="sample_directory">sample_directory</a> 7432 (default: /etc/postfix)</b></DT><DD> 7433 7434 <p> 7435 The name of the directory with example Postfix configuration files. 7436 </p> 7437 7438 7439 </DD> 7440 7441 <DT><b><a name="send_cyrus_sasl_authzid">send_cyrus_sasl_authzid</a> 7442 (default: no)</b></DT><DD> 7443 7444 <p> When authenticating to a remote SMTP or LMTP server with the 7445 default setting "no", send no SASL authoriZation ID (authzid); send 7446 only the SASL authentiCation ID (authcid) plus the authcid's password. 7447 </p> 7448 7449 <p> The non-default setting "yes" enables the behavior of older 7450 Postfix versions. These always send a SASL authzid that is equal 7451 to the SASL authcid, but this causes inter-operability problems 7452 with some SMTP servers. </p> 7453 7454 <p> This feature is available in Postfix 2.4.4 and later. </p> 7455 7456 7457 </DD> 7458 7459 <DT><b><a name="sender_based_routing">sender_based_routing</a> 7460 (default: no)</b></DT><DD> 7461 7462 <p> 7463 This parameter should not be used. It was replaced by <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> 7464 in Postfix version 2.3. 7465 </p> 7466 7467 7468 </DD> 7469 7470 <DT><b><a name="sender_bcc_maps">sender_bcc_maps</a> 7471 (default: empty)</b></DT><DD> 7472 7473 <p> Optional BCC (blind carbon-copy) address lookup tables, indexed 7474 by sender address. The BCC address (multiple results are not 7475 supported) is added when mail enters from outside of Postfix. </p> 7476 7477 <p> 7478 This feature is available in Postfix 2.1 and later. 7479 </p> 7480 7481 <p> 7482 The table search order is as follows: 7483 </p> 7484 7485 <ul> 7486 7487 <li> Look up the "user+extension (a] domain.tld" address including the 7488 optional address extension. 7489 7490 <li> Look up the "user (a] domain.tld" address without the optional 7491 address extension. 7492 7493 <li> Look up the "user+extension" address local part when the 7494 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> 7495 or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. 7496 7497 <li> Look up the "user" address local part when the sender domain 7498 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>. 7499 7500 <li> Look up the "@domain.tld" part. 7501 7502 </ul> 7503 7504 <p> 7505 Specify the types and names of databases to use. After change, 7506 run "<b>postmap /etc/postfix/sender_bcc</b>". 7507 </p> 7508 7509 <p> 7510 Note: if mail to the BCC address bounces it will be returned to 7511 the sender. 7512 </p> 7513 7514 <p> Note: automatic BCC recipients are produced only for new mail. 7515 To avoid mailer loops, automatic BCC recipients are not generated 7516 for mail that Postfix forwards internally, nor for mail that Postfix 7517 generates itself. </p> 7518 7519 <p> 7520 Example: 7521 </p> 7522 7523 <pre> 7524 <a href="postconf.5.html#sender_bcc_maps">sender_bcc_maps</a> = hash:/etc/postfix/sender_bcc 7525 </pre> 7526 7527 7528 </DD> 7529 7530 <DT><b><a name="sender_canonical_classes">sender_canonical_classes</a> 7531 (default: envelope_sender, header_sender)</b></DT><DD> 7532 7533 <p> What addresses are subject to <a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> address 7534 mapping. By default, <a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> address mapping is 7535 applied to envelope sender addresses, and to header sender addresses. 7536 </p> 7537 7538 <p> Specify one or more of: envelope_sender, header_sender </p> 7539 7540 <p> This feature is available in Postfix 2.2 and later. </p> 7541 7542 7543 </DD> 7544 7545 <DT><b><a name="sender_canonical_maps">sender_canonical_maps</a> 7546 (default: empty)</b></DT><DD> 7547 7548 <p> 7549 Optional address mapping lookup tables for envelope and header 7550 sender addresses. 7551 The table format and lookups are documented in <a href="canonical.5.html">canonical(5)</a>. 7552 </p> 7553 7554 <p> 7555 Example: you want to rewrite the SENDER address "user (a] ugly.domain" 7556 to "user (a] pretty.domain", while still being able to send mail to 7557 the RECIPIENT address "user (a] ugly.domain". 7558 </p> 7559 7560 <p> 7561 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>. 7562 </p> 7563 7564 <p> 7565 Example: 7566 </p> 7567 7568 <pre> 7569 <a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> = hash:/etc/postfix/sender_canonical 7570 </pre> 7571 7572 7573 </DD> 7574 7575 <DT><b><a name="sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> 7576 (default: empty)</b></DT><DD> 7577 7578 <p> A sender-dependent override for the global <a href="postconf.5.html#relayhost">relayhost</a> parameter 7579 setting. The tables are searched by the envelope sender address and 7580 @domain. A lookup result of DUNNO terminates the search without 7581 overriding the global <a href="postconf.5.html#relayhost">relayhost</a> parameter setting (Postfix 2.6 and 7582 later). This information is overruled with <a href="postconf.5.html#relay_transport">relay_transport</a>, 7583 <a href="postconf.5.html#default_transport">default_transport</a> and with the <a href="transport.5.html">transport(5)</a> table. </p> 7584 7585 <p> For safety reasons, this feature does not allow $number 7586 substitutions in regular expression maps. </p> 7587 7588 <p> 7589 This feature is available in Postfix 2.3 and later. 7590 </p> 7591 7592 7593 </DD> 7594 7595 <DT><b><a name="sendmail_path">sendmail_path</a> 7596 (default: see "postconf -d" output)</b></DT><DD> 7597 7598 <p> 7599 A Sendmail compatibility feature that specifies the location of 7600 the Postfix <a href="sendmail.1.html">sendmail(1)</a> command. This command can be used to 7601 submit mail into the Postfix queue. 7602 </p> 7603 7604 7605 </DD> 7606 7607 <DT><b><a name="service_throttle_time">service_throttle_time</a> 7608 (default: 60s)</b></DT><DD> 7609 7610 <p> 7611 How long the Postfix <a href="master.8.html">master(8)</a> waits before forking a server that 7612 appears to be malfunctioning. 7613 </p> 7614 7615 <p> 7616 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7617 The default time unit is s (seconds). 7618 </p> 7619 7620 7621 </DD> 7622 7623 <DT><b><a name="setgid_group">setgid_group</a> 7624 (default: postdrop)</b></DT><DD> 7625 7626 <p> 7627 The group ownership of set-gid Postfix commands and of group-writable 7628 Postfix directories. When this parameter value is changed you need 7629 to re-run "<b>postfix set-permissions</b>" (with Postfix version 2.0 and 7630 earlier: "<b>/etc/postfix/post-install set-permissions</b>". 7631 </p> 7632 7633 7634 </DD> 7635 7636 <DT><b><a name="show_user_unknown_table_name">show_user_unknown_table_name</a> 7637 (default: yes)</b></DT><DD> 7638 7639 <p> 7640 Display the name of the recipient table in the "User unknown" 7641 responses. The extra detail makes trouble shooting easier but also 7642 reveals information that is nobody elses business. 7643 </p> 7644 7645 <p> 7646 This feature is available in Postfix 2.0 and later. 7647 </p> 7648 7649 7650 </DD> 7651 7652 <DT><b><a name="showq_service_name">showq_service_name</a> 7653 (default: showq)</b></DT><DD> 7654 7655 <p> 7656 The name of the <a href="showq.8.html">showq(8)</a> service. This service produces mail queue 7657 status reports. 7658 </p> 7659 7660 <p> 7661 This feature is available in Postfix 2.0 and later. 7662 </p> 7663 7664 7665 </DD> 7666 7667 <DT><b><a name="smtp_always_send_ehlo">smtp_always_send_ehlo</a> 7668 (default: yes)</b></DT><DD> 7669 7670 <p> 7671 Always send EHLO at the start of an SMTP session. 7672 </p> 7673 7674 <p> 7675 With "<a href="postconf.5.html#smtp_always_send_ehlo">smtp_always_send_ehlo</a> = no", Postfix sends EHLO only when 7676 the word "ESMTP" appears in the server greeting banner (example: 7677 220 spike.porcupine.org ESMTP Postfix). 7678 </p> 7679 7680 7681 </DD> 7682 7683 <DT><b><a name="smtp_bind_address">smtp_bind_address</a> 7684 (default: empty)</b></DT><DD> 7685 7686 <p> 7687 An optional numerical network address that the Postfix SMTP client 7688 should bind to when making an IPv4 connection. 7689 </p> 7690 7691 <p> 7692 This can be specified in the <a href="postconf.5.html">main.cf</a> file for all SMTP clients, or 7693 it can be specified in the <a href="master.5.html">master.cf</a> file for a specific client, 7694 for example: 7695 </p> 7696 7697 <blockquote> 7698 <pre> 7699 /etc/postfix/<a href="master.5.html">master.cf</a>: 7700 smtp ... smtp -o <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a>=11.22.33.44 7701 </pre> 7702 </blockquote> 7703 7704 <p> Note 1: when <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> specifies no more than one IPv4 7705 address, and that address is a non-loopback address, it is 7706 automatically used as the <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a>. This supports virtual 7707 IP hosting, but can be a problem on multi-homed firewalls. See the 7708 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> documentation for more detail. </p> 7709 7710 <p> Note 2: address information may be enclosed inside <tt>[]</tt>, 7711 but this form is not required here. </p> 7712 7713 7714 </DD> 7715 7716 <DT><b><a name="smtp_bind_address6">smtp_bind_address6</a> 7717 (default: empty)</b></DT><DD> 7718 7719 <p> 7720 An optional numerical network address that the Postfix SMTP client 7721 should bind to when making an IPv6 connection. 7722 </p> 7723 7724 <p> This feature is available in Postfix 2.2 and later. </p> 7725 7726 <p> 7727 This can be specified in the <a href="postconf.5.html">main.cf</a> file for all SMTP clients, or 7728 it can be specified in the <a href="master.5.html">master.cf</a> file for a specific client, 7729 for example: 7730 </p> 7731 7732 <blockquote> 7733 <pre> 7734 /etc/postfix/<a href="master.5.html">master.cf</a>: 7735 smtp ... smtp -o <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a>=1:2:3:4:5:6:7:8 7736 </pre> 7737 </blockquote> 7738 7739 <p> Note 1: when <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> specifies no more than one IPv6 7740 address, and that address is a non-loopback address, it is 7741 automatically used as the <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a>. This supports virtual 7742 IP hosting, but can be a problem on multi-homed firewalls. See the 7743 <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> documentation for more detail. </p> 7744 7745 <p> Note 2: address information may be enclosed inside <tt>[]</tt>, 7746 but this form is not recommended here. </p> 7747 7748 7749 </DD> 7750 7751 <DT><b><a name="smtp_body_checks">smtp_body_checks</a> 7752 (default: empty)</b></DT><DD> 7753 7754 <p> Restricted <a href="header_checks.5.html">body_checks(5)</a> tables for the Postfix SMTP client. 7755 These tables are searched while mail is being delivered. Actions 7756 that change the delivery time or destination are not available. 7757 </p> 7758 7759 <p> This feature is available in Postfix 2.5 and later. </p> 7760 7761 7762 </DD> 7763 7764 <DT><b><a name="smtp_cname_overrides_servername">smtp_cname_overrides_servername</a> 7765 (default: version dependent)</b></DT><DD> 7766 7767 <p> Allow DNS CNAME records to override the servername that the 7768 Postfix SMTP client uses for logging, SASL password lookup, TLS 7769 policy decisions, or TLS certificate verification. The value "no" 7770 hardens Postfix <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> hostname-based policies against 7771 false hostname information in DNS CNAME records, and makes SASL 7772 password file lookups more predictable. This is the default setting 7773 as of Postfix 2.3. </p> 7774 7775 <p> This feature is available in Postfix 2.2.9 and later. </p> 7776 7777 7778 </DD> 7779 7780 <DT><b><a name="smtp_connect_timeout">smtp_connect_timeout</a> 7781 (default: 30s)</b></DT><DD> 7782 7783 <p> 7784 The SMTP client time limit for completing a TCP connection, or 7785 zero (use the operating system built-in time limit). 7786 </p> 7787 7788 <p> 7789 When no connection can be made within the deadline, the Postfix 7790 SMTP client 7791 tries the next address on the mail exchanger list. Specify 0 to 7792 disable the time limit (i.e. use whatever timeout is implemented by 7793 the operating system). 7794 </p> 7795 7796 <p> 7797 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7798 The default time unit is s (seconds). 7799 </p> 7800 7801 7802 </DD> 7803 7804 <DT><b><a name="smtp_connection_cache_destinations">smtp_connection_cache_destinations</a> 7805 (default: empty)</b></DT><DD> 7806 7807 <p> Permanently enable SMTP connection caching for the specified 7808 destinations. With SMTP connection caching, a connection is not 7809 closed immediately after completion of a mail transaction. Instead, 7810 the connection is kept open for up to $<a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> 7811 seconds. This allows connections to be reused for other deliveries, 7812 and can improve mail delivery performance. </p> 7813 7814 <p> Specify a comma or white space separated list of destinations 7815 or pseudo-destinations: </p> 7816 7817 <ul> 7818 7819 <li> if mail is sent without a <a href="postconf.5.html#relayhost">relay host</a>: a domain name (the 7820 right-hand side of an email address, without the [] around a numeric 7821 IP address), 7822 7823 <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 7824 [] or non-default TCP port), as specified in <a href="postconf.5.html">main.cf</a> or in the 7825 transport map, 7826 7827 <li> if mail is sent via a UNIX-domain socket: a pathname (without 7828 the unix: prefix), 7829 7830 <li> a /file/name with domain names and/or <a href="postconf.5.html#relayhost">relay host</a> names as 7831 defined above, 7832 7833 <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 7834 the left-hand side. The right-hand side result from "<a href="DATABASE_README.html">type:table</a>" 7835 lookups is ignored. 7836 7837 </ul> 7838 7839 <p> This feature is available in Postfix 2.2 and later. </p> 7840 7841 7842 </DD> 7843 7844 <DT><b><a name="smtp_connection_cache_on_demand">smtp_connection_cache_on_demand</a> 7845 (default: yes)</b></DT><DD> 7846 7847 <p> Temporarily enable SMTP connection caching while a destination 7848 has a high volume of mail in the <a href="QSHAPE_README.html#active_queue">active queue</a>. With SMTP connection 7849 caching, a connection is not closed immediately after completion 7850 of a mail transaction. Instead, the connection is kept open for 7851 up to $<a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> seconds. This allows 7852 connections to be reused for other deliveries, and can improve mail 7853 delivery performance. </p> 7854 7855 <p> This feature is available in Postfix 2.2 and later. </p> 7856 7857 7858 </DD> 7859 7860 <DT><b><a name="smtp_connection_cache_reuse_limit">smtp_connection_cache_reuse_limit</a> 7861 (default: 10)</b></DT><DD> 7862 7863 <p> When SMTP connection caching is enabled, the number of times that 7864 an SMTP session may be reused before it is closed. 7865 </p> 7866 7867 <p> This feature is available in Postfix 2.2. In Postfix 2.3 it is 7868 replaced by $<a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a>.</p> 7869 7870 7871 </DD> 7872 7873 <DT><b><a name="smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> 7874 (default: 2s)</b></DT><DD> 7875 7876 <p> When SMTP connection caching is enabled, the amount of time that 7877 an unused SMTP client socket is kept open before it is closed. Do 7878 not specify larger values without permission from the remote sites. 7879 </p> 7880 7881 <p> This feature is available in Postfix 2.2 and later. </p> 7882 7883 7884 </DD> 7885 7886 <DT><b><a name="smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a> 7887 (default: 300s)</b></DT><DD> 7888 7889 <p> The amount of time during which Postfix will use an SMTP 7890 connection repeatedly. The timer starts when the connection is 7891 initiated (i.e. it includes the connect, greeting and helo latency, 7892 in addition to the latencies of subsequent mail delivery transactions). 7893 </p> 7894 7895 <p> This feature addresses a performance stability problem with 7896 remote SMTP servers. This problem is not specific to Postfix: it 7897 can happen when any MTA sends large amounts of SMTP email to a site 7898 that has multiple MX hosts. </p> 7899 7900 <p> The problem starts when one of a set of MX hosts becomes slower 7901 than the rest. Even though SMTP clients connect to fast and slow 7902 MX hosts with equal probability, the slow MX host ends up with more 7903 simultaneous inbound connections than the faster MX hosts, because 7904 the slow MX host needs more time to serve each client request. </p> 7905 7906 <p> The slow MX host becomes a connection attractor. If one MX 7907 host becomes N times slower than the rest, it dominates mail delivery 7908 latency unless there are more than N fast MX hosts to counter the 7909 effect. And if the number of MX hosts is smaller than N, the mail 7910 delivery latency becomes effectively that of the slowest MX host 7911 divided by the total number of MX hosts. </p> 7912 7913 <p> The solution uses connection caching in a way that differs from 7914 Postfix version 2.2. By limiting the amount of time during which a connection 7915 can be used repeatedly (instead of limiting the number of deliveries 7916 over that connection), Postfix not only restores fairness in the 7917 distribution of simultaneous connections across a set of MX hosts, 7918 it also favors deliveries over connections that perform well, which 7919 is exactly what we want. </p> 7920 7921 <p> The default reuse time limit, 300s, is comparable to the various 7922 smtp transaction timeouts which are fair estimates of maximum excess 7923 latency for a slow delivery. Note that hosts may accept thousands 7924 of messages over a single connection within the default connection 7925 reuse time limit. This number is much larger than the default Postfix 7926 version 2.2 limit of 10 messages per cached connection. It may prove necessary 7927 to lower the limit to avoid interoperability issues with MTAs that 7928 exhibit bugs when many messages are delivered via a single connection. 7929 A lower reuse time limit risks losing the benefit of connection 7930 reuse when the average connection and mail delivery latency exceeds 7931 the reuse time limit. </p> 7932 7933 <p> This feature is available in Postfix 2.3 and later. </p> 7934 7935 7936 </DD> 7937 7938 <DT><b><a name="smtp_data_done_timeout">smtp_data_done_timeout</a> 7939 (default: 600s)</b></DT><DD> 7940 7941 <p> 7942 The SMTP client time limit for sending the SMTP ".", and for receiving 7943 the server response. 7944 </p> 7945 7946 <p> 7947 When no response is received within the deadline, a warning is 7948 logged that the mail may be delivered multiple times. 7949 </p> 7950 7951 <p> 7952 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7953 The default time unit is s (seconds). 7954 </p> 7955 7956 7957 </DD> 7958 7959 <DT><b><a name="smtp_data_init_timeout">smtp_data_init_timeout</a> 7960 (default: 120s)</b></DT><DD> 7961 7962 <p> 7963 The SMTP client time limit for sending the SMTP DATA command, and for 7964 receiving the server response. 7965 </p> 7966 7967 <p> 7968 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7969 The default time unit is s (seconds). 7970 </p> 7971 7972 7973 </DD> 7974 7975 <DT><b><a name="smtp_data_xfer_timeout">smtp_data_xfer_timeout</a> 7976 (default: 180s)</b></DT><DD> 7977 7978 <p> 7979 The SMTP client time limit for sending the SMTP message content. 7980 When the connection makes no progress for more than $<a href="postconf.5.html#smtp_data_xfer_timeout">smtp_data_xfer_timeout</a> 7981 seconds the Postfix SMTP client terminates the transfer. 7982 </p> 7983 7984 <p> 7985 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 7986 The default time unit is s (seconds). 7987 </p> 7988 7989 7990 </DD> 7991 7992 <DT><b><a name="smtp_defer_if_no_mx_address_found">smtp_defer_if_no_mx_address_found</a> 7993 (default: no)</b></DT><DD> 7994 7995 <p> 7996 Defer mail delivery when no MX record resolves to an IP address. 7997 </p> 7998 7999 <p> 8000 The default (no) is to return the mail as undeliverable. With older 8001 Postfix versions the default was to keep trying to deliver the mail 8002 until someone fixed the MX record or until the mail was too old. 8003 </p> 8004 8005 <p> 8006 Note: Postfix always ignores MX records with equal or worse preference 8007 than the local MTA itself. 8008 </p> 8009 8010 <p> 8011 This feature is available in Postfix 2.1 and later. 8012 </p> 8013 8014 8015 </DD> 8016 8017 <DT><b><a name="smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a> 8018 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 8019 8020 <p> The maximal number of parallel deliveries to the same destination 8021 via the smtp message delivery transport. This limit is enforced by 8022 the queue manager. The message delivery transport name is the first 8023 field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 8024 8025 8026 </DD> 8027 8028 <DT><b><a name="smtp_destination_recipient_limit">smtp_destination_recipient_limit</a> 8029 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 8030 8031 <p> The maximal number of recipients per message for the smtp 8032 message delivery transport. This limit is enforced by the queue 8033 manager. The message delivery transport name is the first field in 8034 the entry in the <a href="master.5.html">master.cf</a> file. </p> 8035 8036 <p> Setting this parameter to a value of 1 changes the meaning of 8037 <a href="postconf.5.html#smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a> from concurrency per domain 8038 into concurrency per recipient. </p> 8039 8040 8041 </DD> 8042 8043 <DT><b><a name="smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a> 8044 (default: empty)</b></DT><DD> 8045 8046 <p> Lookup tables, indexed by the remote SMTP server address, with 8047 case insensitive lists of EHLO keywords (pipelining, starttls, auth, 8048 etc.) that the Postfix SMTP client will ignore in the EHLO response from a 8049 remote SMTP server. See <a href="postconf.5.html#smtp_discard_ehlo_keywords">smtp_discard_ehlo_keywords</a> for details. The 8050 table is not indexed by hostname for consistency with 8051 <a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a>. </p> 8052 8053 <p> This feature is available in Postfix 2.2 and later. </p> 8054 8055 8056 </DD> 8057 8058 <DT><b><a name="smtp_discard_ehlo_keywords">smtp_discard_ehlo_keywords</a> 8059 (default: empty)</b></DT><DD> 8060 8061 <p> A case insensitive list of EHLO keywords (pipelining, starttls, 8062 auth, etc.) that the Postfix SMTP client will ignore in the EHLO 8063 response from a remote SMTP server. </p> 8064 8065 <p> This feature is available in Postfix 2.2 and later. </p> 8066 8067 <p> Notes: </p> 8068 8069 <ul> 8070 8071 <li> <p> Specify the <b>silent-discard</b> pseudo keyword to prevent 8072 this action from being logged. </p> 8073 8074 <li> <p> Use the <a href="postconf.5.html#smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a> feature to 8075 discard EHLO keywords selectively. </p> 8076 8077 </ul> 8078 8079 8080 </DD> 8081 8082 <DT><b><a name="smtp_enforce_tls">smtp_enforce_tls</a> 8083 (default: no)</b></DT><DD> 8084 8085 <p> Enforcement mode: require that remote SMTP servers use TLS 8086 encryption, and never send mail in the clear. This also requires 8087 that the remote SMTP server hostname matches the information in 8088 the remote server certificate, and that the remote SMTP server 8089 certificate was issued by a CA that is trusted by the Postfix SMTP 8090 client. If the certificate doesn't verify or the hostname doesn't 8091 match, delivery is deferred and mail stays in the queue. </p> 8092 8093 <p> The server hostname is matched against all names provided as 8094 dNSNames in the SubjectAlternativeName. If no dNSNames are specified, 8095 the CommonName is checked. The behavior may be changed with the 8096 <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> option. </p> 8097 8098 <p> This option is useful only if you are definitely sure that you 8099 will only connect to servers that support <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> _and_ that 8100 provide valid server certificates. Typical use is for clients that 8101 send all their email to a dedicated mailhub. </p> 8102 8103 <p> This feature is available in Postfix 2.2 and later. With 8104 Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> instead. </p> 8105 8106 8107 </DD> 8108 8109 <DT><b><a name="smtp_fallback_relay">smtp_fallback_relay</a> 8110 (default: $<a href="postconf.5.html#fallback_relay">fallback_relay</a>)</b></DT><DD> 8111 8112 <p> 8113 Optional list of relay hosts for SMTP destinations that can't be 8114 found or that are unreachable. With Postfix 2.2 and earlier this 8115 parameter is called <a href="postconf.5.html#fallback_relay">fallback_relay</a>. </p> 8116 8117 <p> 8118 By default, mail is returned to the sender when a destination is 8119 not found, and delivery is deferred when a destination is unreachable. 8120 </p> 8121 8122 <p> The fallback relays must be SMTP destinations. Specify a domain, 8123 host, host:port, [host]:port, [address] or [address]:port; the form 8124 [host] turns off MX lookups. If you specify multiple SMTP 8125 destinations, Postfix will try them in the specified order. </p> 8126 8127 <p> To prevent mailer loops between MX hosts and fall-back hosts, 8128 Postfix version 2.2 and later will not use the fallback relays for 8129 destinations that it is MX host for (assuming DNS lookup is turned on). 8130 </p> 8131 8132 8133 </DD> 8134 8135 <DT><b><a name="smtp_generic_maps">smtp_generic_maps</a> 8136 (default: empty)</b></DT><DD> 8137 8138 <p> Optional lookup tables that perform address rewriting in the 8139 SMTP client, typically to transform a locally valid address into 8140 a globally valid address when sending mail across the Internet. 8141 This is needed when the local machine does not have its own Internet 8142 domain name, but uses something like <i>localdomain.local</i> 8143 instead. </p> 8144 8145 <p> The table format and lookups are documented in <a href="generic.5.html">generic(5)</a>; 8146 examples are shown in the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> and 8147 <a href="STANDARD_CONFIGURATION_README.html">STANDARD_CONFIGURATION_README</a> documents. </p> 8148 8149 <p> This feature is available in Postfix 2.2 and later. </p> 8150 8151 8152 </DD> 8153 8154 <DT><b><a name="smtp_header_checks">smtp_header_checks</a> 8155 (default: empty)</b></DT><DD> 8156 8157 <p> Restricted <a href="header_checks.5.html">header_checks(5)</a> tables for the Postfix SMTP client. 8158 These tables are searched while mail is being delivered. Actions 8159 that change the delivery time or destination are not available. 8160 </p> 8161 8162 <p> This feature is available in Postfix 2.5 and later. </p> 8163 8164 8165 </DD> 8166 8167 <DT><b><a name="smtp_helo_name">smtp_helo_name</a> 8168 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 8169 8170 <p> 8171 The hostname to send in the SMTP EHLO or HELO command. 8172 </p> 8173 8174 <p> 8175 The default value is the machine hostname. Specify a hostname or 8176 [ip.add.re.ss]. 8177 </p> 8178 8179 <p> 8180 This information can be specified in the <a href="postconf.5.html">main.cf</a> file for all SMTP 8181 clients, or it can be specified in the <a href="master.5.html">master.cf</a> file for a specific 8182 client, for example: 8183 </p> 8184 8185 <blockquote> 8186 <pre> 8187 /etc/postfix/<a href="master.5.html">master.cf</a>: 8188 mysmtp ... smtp -o <a href="postconf.5.html#smtp_helo_name">smtp_helo_name</a>=foo.bar.com 8189 </pre> 8190 </blockquote> 8191 8192 <p> 8193 This feature is available in Postfix 2.0 and later. 8194 </p> 8195 8196 8197 </DD> 8198 8199 <DT><b><a name="smtp_helo_timeout">smtp_helo_timeout</a> 8200 (default: 300s)</b></DT><DD> 8201 8202 <p> 8203 The SMTP client time limit for sending the HELO or EHLO command, 8204 and for receiving the initial server response. 8205 </p> 8206 8207 <p> 8208 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 8209 The default time unit is s (seconds). 8210 </p> 8211 8212 8213 </DD> 8214 8215 <DT><b><a name="smtp_host_lookup">smtp_host_lookup</a> 8216 (default: dns)</b></DT><DD> 8217 8218 <p> 8219 What mechanisms when the Postfix SMTP client uses to look up a host's IP 8220 address. This parameter is ignored when DNS lookups are disabled. 8221 </p> 8222 8223 <p> 8224 Specify one of the following: 8225 </p> 8226 8227 <dl> 8228 8229 <dt><b>dns</b></dt> 8230 8231 <dd>Hosts can be found in the DNS (preferred). </dd> 8232 8233 <dt><b>native</b></dt> 8234 8235 <dd>Use the native naming service only (nsswitch.conf, or equivalent 8236 mechanism). </dd> 8237 8238 <dt><b>dns, native</b></dt> 8239 8240 <dd>Use the native service for hosts not found in the DNS. </dd> 8241 8242 </dl> 8243 8244 <p> 8245 This feature is available in Postfix 2.1 and later. 8246 </p> 8247 8248 8249 </DD> 8250 8251 <DT><b><a name="smtp_line_length_limit">smtp_line_length_limit</a> 8252 (default: 990)</b></DT><DD> 8253 8254 <p> 8255 The maximal length of message header and body lines that Postfix 8256 will send via SMTP. Longer lines are broken by inserting 8257 "<CR><LF><SPACE>". This minimizes the damage to 8258 MIME formatted mail. 8259 </p> 8260 8261 <p> 8262 By default, the line length is limited to 990 characters, because 8263 some server implementations cannot receive mail with long lines. 8264 </p> 8265 8266 8267 </DD> 8268 8269 <DT><b><a name="smtp_mail_timeout">smtp_mail_timeout</a> 8270 (default: 300s)</b></DT><DD> 8271 8272 <p> 8273 The SMTP client time limit for sending the MAIL FROM command, and 8274 for receiving the server response. 8275 </p> 8276 8277 <p> 8278 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 8279 The default time unit is s (seconds). 8280 </p> 8281 8282 8283 </DD> 8284 8285 <DT><b><a name="smtp_mime_header_checks">smtp_mime_header_checks</a> 8286 (default: empty)</b></DT><DD> 8287 8288 <p> Restricted mime_<a href="header_checks.5.html">header_checks(5)</a> tables for the Postfix SMTP 8289 client. These tables are searched while mail is being delivered. 8290 Actions that change the delivery time or destination are not 8291 available. </p> 8292 8293 <p> This feature is available in Postfix 2.5 and later. </p> 8294 8295 8296 </DD> 8297 8298 <DT><b><a name="smtp_mx_address_limit">smtp_mx_address_limit</a> 8299 (default: 5)</b></DT><DD> 8300 8301 <p> 8302 The maximal number of MX (mail exchanger) IP addresses that can 8303 result from mail exchanger lookups, or zero (no limit). Prior to 8304 Postfix version 2.3, this limit was disabled by default. 8305 </p> 8306 8307 <p> 8308 This feature is available in Postfix 2.1 and later. 8309 </p> 8310 8311 8312 </DD> 8313 8314 <DT><b><a name="smtp_mx_session_limit">smtp_mx_session_limit</a> 8315 (default: 2)</b></DT><DD> 8316 8317 <p> The maximal number of SMTP sessions per delivery request before 8318 giving up or delivering to a fall-back <a href="postconf.5.html#relayhost">relay host</a>, or zero (no 8319 limit). This restriction ignores sessions that fail to complete the 8320 SMTP initial handshake (Postfix version 2.2 and earlier) or that fail to 8321 complete the EHLO and TLS handshake (Postfix version 2.3 and later). </p> 8322 8323 <p> This feature is available in Postfix 2.1 and later. </p> 8324 8325 8326 </DD> 8327 8328 <DT><b><a name="smtp_nested_header_checks">smtp_nested_header_checks</a> 8329 (default: empty)</b></DT><DD> 8330 8331 <p> Restricted nested_<a href="header_checks.5.html">header_checks(5)</a> tables for the Postfix SMTP 8332 client. These tables are searched while mail is being delivered. 8333 Actions that change the delivery time or destination are not 8334 available. </p> 8335 8336 <p> This feature is available in Postfix 2.5 and later. </p> 8337 8338 8339 </DD> 8340 8341 <DT><b><a name="smtp_never_send_ehlo">smtp_never_send_ehlo</a> 8342 (default: no)</b></DT><DD> 8343 8344 <p> Never send EHLO at the start of an SMTP session. See also the 8345 <a href="postconf.5.html#smtp_always_send_ehlo">smtp_always_send_ehlo</a> parameter. </p> 8346 8347 8348 </DD> 8349 8350 <DT><b><a name="smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a> 8351 (default: 10s)</b></DT><DD> 8352 8353 <p> 8354 How long the Postfix SMTP client pauses before sending 8355 ".<CR><LF>" in order to work around the PIX firewall 8356 "<CR><LF>.<CR><LF>" bug. 8357 </p> 8358 8359 <p> 8360 Choosing a too short time makes this workaround ineffective when 8361 sending large messages over slow network connections. 8362 </p> 8363 8364 8365 </DD> 8366 8367 <DT><b><a name="smtp_pix_workaround_maps">smtp_pix_workaround_maps</a> 8368 (default: empty)</b></DT><DD> 8369 8370 <p> Lookup tables, indexed by the remote SMTP server address, with 8371 per-destination workarounds for CISCO PIX firewall bugs. The table 8372 is not indexed by hostname for consistency with 8373 <a href="postconf.5.html#smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a>. </p> 8374 8375 <p> This feature is available in Postfix 2.4 and later. </p> 8376 8377 8378 </DD> 8379 8380 <DT><b><a name="smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a> 8381 (default: 500s)</b></DT><DD> 8382 8383 <p> How long a message must be queued before the Postfix SMTP client 8384 turns on the PIX firewall "<CR><LF>.<CR><LF>" 8385 bug workaround for delivery through firewalls with "smtp fixup" 8386 mode turned on. </p> 8387 8388 <p> 8389 By default, the workaround is turned off for mail that is queued 8390 for less than 500 seconds. In other words, the workaround is normally 8391 turned off for the first delivery attempt. 8392 </p> 8393 8394 <p> 8395 Specify 0 to enable the PIX firewall 8396 "<CR><LF>.<CR><LF>" bug workaround upon the 8397 first delivery attempt. 8398 </p> 8399 8400 8401 </DD> 8402 8403 <DT><b><a name="smtp_pix_workarounds">smtp_pix_workarounds</a> 8404 (default: disable_esmtp, delay_dotcrlf)</b></DT><DD> 8405 8406 <p> A list that specifies zero or more workarounds for CISCO PIX 8407 firewall bugs. These workarounds are implemented by the Postfix 8408 SMTP client. Workaround names are separated by comma or space, and 8409 are case insensitive. This parameter setting can be overruled with 8410 per-destination <a href="postconf.5.html#smtp_pix_workaround_maps">smtp_pix_workaround_maps</a> settings. </p> 8411 8412 <dl> 8413 8414 <dt><b>delay_dotcrlf</b><dd> Insert a delay before sending 8415 ".<CR><LF>" after the end of the message content. The 8416 delay is subject to the <a href="postconf.5.html#smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a> and 8417 <a href="postconf.5.html#smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a> parameter settings. </dd> 8418 8419 <dt><b>disable_esmtp</b><dd> Disable all extended SMTP commands: 8420 send HELO instead of EHLO. </dd> 8421 8422 </dl> 8423 8424 <p> This feature is available in Postfix 2.4 and later. The default 8425 settings are backwards compatible with earlier Postfix versions. 8426 </p> 8427 8428 8429 </DD> 8430 8431 <DT><b><a name="smtp_quit_timeout">smtp_quit_timeout</a> 8432 (default: 300s)</b></DT><DD> 8433 8434 <p> 8435 The SMTP client time limit for sending the QUIT command, and for 8436 receiving the server response. 8437 </p> 8438 8439 <p> 8440 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 8441 The default time unit is s (seconds). 8442 </p> 8443 8444 8445 </DD> 8446 8447 <DT><b><a name="smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a> 8448 (default: yes)</b></DT><DD> 8449 8450 <p> 8451 Quote addresses in SMTP MAIL FROM and RCPT TO commands as required 8452 by <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. This includes putting quotes around an address localpart 8453 that ends in ".". 8454 </p> 8455 8456 <p> 8457 The default is to comply with <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. If you have to send mail to 8458 a broken SMTP server, configure a special SMTP client in <a href="master.5.html">master.cf</a>: 8459 </p> 8460 8461 <blockquote> 8462 <pre> 8463 /etc/postfix/<a href="master.5.html">master.cf</a>: 8464 broken-smtp . . . smtp -o <a href="postconf.5.html#smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a>=no 8465 </pre> 8466 </blockquote> 8467 8468 <p> 8469 and route mail for the destination in question to the "broken-smtp" 8470 message delivery with a <a href="transport.5.html">transport(5)</a> table. 8471 </p> 8472 8473 <p> 8474 This feature is available in Postfix 2.1 and later. 8475 </p> 8476 8477 8478 </DD> 8479 8480 <DT><b><a name="smtp_randomize_addresses">smtp_randomize_addresses</a> 8481 (default: yes)</b></DT><DD> 8482 8483 <p> 8484 Randomize the order of equal-preference MX host addresses. This 8485 is a performance feature of the Postfix SMTP client. 8486 </p> 8487 8488 8489 </DD> 8490 8491 <DT><b><a name="smtp_rcpt_timeout">smtp_rcpt_timeout</a> 8492 (default: 300s)</b></DT><DD> 8493 8494 <p> 8495 The SMTP client time limit for sending the SMTP RCPT TO command, and 8496 for receiving the server response. 8497 </p> 8498 8499 <p> 8500 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 8501 The default time unit is s (seconds). 8502 </p> 8503 8504 8505 </DD> 8506 8507 <DT><b><a name="smtp_rset_timeout">smtp_rset_timeout</a> 8508 (default: 20s)</b></DT><DD> 8509 8510 <p> The SMTP client time limit for sending the RSET command, and 8511 for receiving the server response. The SMTP client sends RSET in 8512 order to finish a recipient address probe, or to verify that a 8513 cached session is still usable. </p> 8514 8515 <p> This feature is available in Postfix 2.1 and later. </p> 8516 8517 8518 </DD> 8519 8520 <DT><b><a name="smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> 8521 (default: empty)</b></DT><DD> 8522 8523 <p> An optional table to prevent repeated SASL authentication 8524 failures with the same remote SMTP server hostname, username and 8525 password. Each table (key, value) pair contains a server name, a 8526 username and password, and the full server response. This information 8527 is stored when a remote SMTP server rejects an authentication attempt 8528 with a 535 reply code. As long as the <a href="postconf.5.html#smtp_sasl_password_maps">smtp_sasl_password_maps</a> 8529 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> 8530 information does not expire (see <a href="postconf.5.html#smtp_sasl_auth_cache_time">smtp_sasl_auth_cache_time</a>) the 8531 Postfix SMTP client avoids SASL authentication attempts with the 8532 same server, username and password, and instead bounces or defers 8533 mail as controlled with the <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> configuration 8534 parameter. </p> 8535 8536 <p> Use a per-destination delivery concurrency of 1 (for example, 8537 "<a href="postconf.5.html#smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a> = 1", 8538 "<a href="postconf.5.html#relay_destination_concurrency_limit">relay_destination_concurrency_limit</a> = 1", etc.), otherwise multiple 8539 delivery agents may experience a login failure at the same time. 8540 </p> 8541 8542 <p> The table must be accessed via the proxywrite service, i.e. the 8543 map name must start with "<a href="proxymap.8.html">proxy</a>:". The table should be stored under 8544 the directory specified with the <a href="postconf.5.html#data_directory">data_directory</a> parameter. </p> 8545 8546 <p> This feature uses cryptographic hashing to protect plain-text 8547 passwords, and requires that Postfix is compiled with TLS support. 8548 </p> 8549 8550 <p> Example: </p> 8551 8552 <pre> 8553 <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/lib/postfix/sasl_auth_cache 8554 </pre> 8555 8556 <p> This feature is available in Postfix 2.5 and later. </p> 8557 8558 8559 </DD> 8560 8561 <DT><b><a name="smtp_sasl_auth_cache_time">smtp_sasl_auth_cache_time</a> 8562 (default: 90d)</b></DT><DD> 8563 8564 <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 8565 is removed. </p> 8566 8567 <p> This feature is available in Postfix 2.5 and later. </p> 8568 8569 8570 </DD> 8571 8572 <DT><b><a name="smtp_sasl_auth_enable">smtp_sasl_auth_enable</a> 8573 (default: no)</b></DT><DD> 8574 8575 <p> 8576 Enable SASL authentication in the Postfix SMTP client. By default, 8577 the Postfix SMTP client uses no authentication. 8578 </p> 8579 8580 <p> 8581 Example: 8582 </p> 8583 8584 <pre> 8585 <a href="postconf.5.html#smtp_sasl_auth_enable">smtp_sasl_auth_enable</a> = yes 8586 </pre> 8587 8588 8589 </DD> 8590 8591 <DT><b><a name="smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> 8592 (default: yes)</b></DT><DD> 8593 8594 <p> When a remote SMTP server rejects a SASL authentication request 8595 with a 535 reply code, defer mail delivery instead of returning 8596 mail as undeliverable. The latter behavior was hard-coded prior to 8597 Postfix version 2.5. </p> 8598 8599 <p> Note: the setting "yes" overrides the global <a href="postconf.5.html#soft_bounce">soft_bounce</a> 8600 parameter, but the setting "no" does not. </p> 8601 8602 <p> Example: </p> 8603 8604 <pre> 8605 # Default as of Postfix 2.5 8606 <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> = yes 8607 # The old hard-coded default 8608 <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> = no 8609 </pre> 8610 8611 <p> This feature is available in Postfix 2.5 and later. </p> 8612 8613 8614 </DD> 8615 8616 <DT><b><a name="smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> 8617 (default: empty)</b></DT><DD> 8618 8619 <p> 8620 If non-empty, a Postfix SMTP client filter for the remote SMTP 8621 server's list of offered SASL mechanisms. Different client and 8622 server implementations may support different mechanism lists. By 8623 default, the Postfix SMTP client will use the intersection of the 8624 two. <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> further restricts what server 8625 mechanisms the client will take into consideration. </p> 8626 8627 <p> Specify mechanism names, "/file/name" patterns or "<a href="DATABASE_README.html">type:table</a>" 8628 lookup tables. The right-hand side result from "<a href="DATABASE_README.html">type:table</a>" lookups 8629 is ignored. Specify "!pattern" to exclude a mechanism name from the 8630 list. The form "!/file/name" is supported only in Postfix version 8631 2.4 and later. </p> 8632 8633 <p> This feature is available in Postfix 2.2 and later. </p> 8634 8635 <p> 8636 Examples: 8637 </p> 8638 8639 <pre> 8640 <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> = plain, login 8641 <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> = /etc/postfix/smtp_mechs 8642 <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> = !gssapi, !login, static:rest 8643 </pre> 8644 8645 8646 </DD> 8647 8648 <DT><b><a name="smtp_sasl_password_maps">smtp_sasl_password_maps</a> 8649 (default: empty)</b></DT><DD> 8650 8651 <p> 8652 Optional SMTP client lookup tables with one username:password entry 8653 per remote hostname or domain, or sender address when sender-dependent 8654 authentication is enabled. If no username:password entry is found, 8655 then the Postfix SMTP client will not 8656 attempt to authenticate to the remote host. 8657 </p> 8658 8659 <p> 8660 The Postfix SMTP client opens the lookup table before going to 8661 chroot jail, so you can leave the password file in /etc/postfix. 8662 </p> 8663 8664 8665 </DD> 8666 8667 <DT><b><a name="smtp_sasl_path">smtp_sasl_path</a> 8668 (default: empty)</b></DT><DD> 8669 8670 <p> Implementation-specific information that the Postfix SMTP client 8671 passes through to 8672 the SASL plug-in implementation that is selected with 8673 <b><a href="postconf.5.html#smtp_sasl_type">smtp_sasl_type</a></b>. Typically this specifies the name of a 8674 configuration file or rendezvous point. </p> 8675 8676 <p> This feature is available in Postfix 2.3 and later. </p> 8677 8678 8679 </DD> 8680 8681 <DT><b><a name="smtp_sasl_security_options">smtp_sasl_security_options</a> 8682 (default: noplaintext, noanonymous)</b></DT><DD> 8683 8684 <p> Postfix SMTP client SASL security options; as of Postfix 2.3 8685 the list of available 8686 features depends on the SASL client implementation that is selected 8687 with <b><a href="postconf.5.html#smtp_sasl_type">smtp_sasl_type</a></b>. </p> 8688 8689 <p> The following security features are defined for the <b>cyrus</b> 8690 client SASL implementation: </p> 8691 8692 <p> 8693 Specify zero or more of the following: 8694 </p> 8695 8696 <dl> 8697 8698 <dt><b>noplaintext</b></dt> 8699 8700 <dd>Disallow methods that use plaintext passwords. </dd> 8701 8702 <dt><b>noactive</b></dt> 8703 8704 <dd>Disallow methods subject to active (non-dictionary) attack. 8705 </dd> 8706 8707 <dt><b>nodictionary</b></dt> 8708 8709 <dd>Disallow methods subject to passive (dictionary) attack. </dd> 8710 8711 <dt><b>noanonymous</b></dt> 8712 8713 <dd>Disallow methods that allow anonymous authentication. </dd> 8714 8715 <dt><b>mutual_auth</b></dt> 8716 8717 <dd>Only allow methods that provide mutual authentication (not 8718 available with SASL version 1). </dd> 8719 8720 </dl> 8721 8722 <p> 8723 Example: 8724 </p> 8725 8726 <pre> 8727 <a href="postconf.5.html#smtp_sasl_security_options">smtp_sasl_security_options</a> = noplaintext 8728 </pre> 8729 8730 8731 </DD> 8732 8733 <DT><b><a name="smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a> 8734 (default: $<a href="postconf.5.html#smtp_sasl_security_options">smtp_sasl_security_options</a>)</b></DT><DD> 8735 8736 <p> The SASL authentication security options that the Postfix SMTP 8737 client uses for TLS encrypted SMTP sessions. </p> 8738 8739 <p> This feature is available in Postfix 2.2 and later. </p> 8740 8741 8742 </DD> 8743 8744 <DT><b><a name="smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a> 8745 (default: $<a href="postconf.5.html#smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a>)</b></DT><DD> 8746 8747 <p> The SASL authentication security options that the Postfix SMTP 8748 client uses for TLS encrypted SMTP sessions with a verified server 8749 certificate. </p> 8750 8751 <p> When mail is sent to the public MX host for the recipient's 8752 domain, server certificates are by default optional, and delivery 8753 proceeds even if certificate verification fails. For delivery via 8754 a submission service that requires SASL authentication, it may be 8755 appropriate to send plaintext passwords only when the connection 8756 to the server is strongly encrypted <b>and</b> the server identity 8757 is verified. </p> 8758 8759 <p> The <a href="postconf.5.html#smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a> parameter makes it 8760 possible to only enable plaintext mechanisms when a secure connection 8761 to the server is available. Submission servers subject to this 8762 policy must either have verifiable certificates or offer suitable 8763 non-plaintext SASL mechanisms. </p> 8764 8765 <p> This feature is available in Postfix 2.6 and later. </p> 8766 8767 8768 </DD> 8769 8770 <DT><b><a name="smtp_sasl_type">smtp_sasl_type</a> 8771 (default: cyrus)</b></DT><DD> 8772 8773 <p> The SASL plug-in type that the Postfix SMTP client should use 8774 for authentication. The available types are listed with the 8775 "<b>postconf -A</b>" command. </p> 8776 8777 <p> This feature is available in Postfix 2.3 and later. </p> 8778 8779 8780 </DD> 8781 8782 <DT><b><a name="smtp_send_xforward_command">smtp_send_xforward_command</a> 8783 (default: no)</b></DT><DD> 8784 8785 <p> 8786 Send the non-standard XFORWARD command when the Postfix SMTP server 8787 EHLO response announces XFORWARD support. 8788 </p> 8789 8790 <p> 8791 This allows an "smtp" delivery agent, used for injecting mail into 8792 a content filter, to forward the name, address, protocol and HELO 8793 name of the original client to the content filter and downstream 8794 queuing SMTP server. This can produce more useful logging than 8795 localhost[127.0.0.1] etc. 8796 </p> 8797 8798 <p> 8799 This feature is available in Postfix 2.1 and later. 8800 </p> 8801 8802 8803 </DD> 8804 8805 <DT><b><a name="smtp_sender_dependent_authentication">smtp_sender_dependent_authentication</a> 8806 (default: no)</b></DT><DD> 8807 8808 <p> 8809 Enable sender-dependent authentication in the Postfix SMTP client; this is 8810 available only with SASL authentication, and disables SMTP connection 8811 caching to ensure that mail from different senders will use the 8812 appropriate credentials. </p> 8813 8814 <p> 8815 This feature is available in Postfix 2.3 and later. 8816 </p> 8817 8818 8819 </DD> 8820 8821 <DT><b><a name="smtp_skip_4xx_greeting">smtp_skip_4xx_greeting</a> 8822 (default: yes)</b></DT><DD> 8823 8824 <p> 8825 Skip SMTP servers that greet with a 4XX status code (go away, try 8826 again later). 8827 </p> 8828 8829 <p> 8830 By default, Postfix moves on the next mail exchanger. Specify 8831 "<a href="postconf.5.html#smtp_skip_4xx_greeting">smtp_skip_4xx_greeting</a> = no" if Postfix should defer delivery 8832 immediately. 8833 </p> 8834 8835 <p> This feature is available in Postfix 2.0 and earlier. 8836 Later Postfix versions always skip SMTP servers that greet with a 8837 4XX status code. </p> 8838 8839 8840 </DD> 8841 8842 <DT><b><a name="smtp_skip_5xx_greeting">smtp_skip_5xx_greeting</a> 8843 (default: yes)</b></DT><DD> 8844 8845 <p> 8846 Skip SMTP servers that greet with a 5XX status code (go away, do 8847 not try again later). 8848 </p> 8849 8850 <p> By default, the Postfix SMTP client moves on the next mail 8851 exchanger. Specify "<a href="postconf.5.html#smtp_skip_5xx_greeting">smtp_skip_5xx_greeting</a> = no" if Postfix should 8852 bounce the mail immediately. The default setting is incorrect, but 8853 it is what a lot of people expect to happen. </p> 8854 8855 8856 </DD> 8857 8858 <DT><b><a name="smtp_skip_quit_response">smtp_skip_quit_response</a> 8859 (default: yes)</b></DT><DD> 8860 8861 <p> 8862 Do not wait for the response to the SMTP QUIT command. 8863 </p> 8864 8865 8866 </DD> 8867 8868 <DT><b><a name="smtp_starttls_timeout">smtp_starttls_timeout</a> 8869 (default: 300s)</b></DT><DD> 8870 8871 <p> Time limit for Postfix SMTP client write and read operations 8872 during TLS startup and shutdown handshake procedures. </p> 8873 8874 <p> This feature is available in Postfix 2.2 and later. </p> 8875 8876 8877 </DD> 8878 8879 <DT><b><a name="smtp_tls_CAfile">smtp_tls_CAfile</a> 8880 (default: empty)</b></DT><DD> 8881 8882 <p> A file containing CA certificates of root CAs trusted to sign 8883 either remote SMTP server certificates or intermediate CA certificates. 8884 These are loaded into memory before the <a href="smtp.8.html">smtp(8)</a> client enters the 8885 chroot jail. If the number of trusted roots is large, consider using 8886 <a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a> instead, but note that the latter directory must be 8887 present in the chroot jail if the <a href="smtp.8.html">smtp(8)</a> client is chrooted. This 8888 file may also be used to augment the client certificate trust chain, 8889 but it is best to include all the required certificates directly in 8890 $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>. </p> 8891 8892 <p> Example: </p> 8893 8894 <pre> 8895 <a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a> = /etc/postfix/CAcert.pem 8896 </pre> 8897 8898 <p> This feature is available in Postfix 2.2 and later. </p> 8899 8900 8901 </DD> 8902 8903 <DT><b><a name="smtp_tls_CApath">smtp_tls_CApath</a> 8904 (default: empty)</b></DT><DD> 8905 8906 <p> Directory with PEM format certificate authority certificates 8907 that the Postfix SMTP client uses to verify a remote SMTP server 8908 certificate. Don't forget to create the necessary "hash" links 8909 with, for example, "$OPENSSL_HOME/bin/c_rehash /etc/postfix/certs". 8910 </p> 8911 8912 <p> To use this option in chroot mode, this directory (or a copy) 8913 must be inside the chroot jail. </p> 8914 8915 <p> Example: </p> 8916 8917 <pre> 8918 <a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a> = /etc/postfix/certs 8919 </pre> 8920 8921 <p> This feature is available in Postfix 2.2 and later. </p> 8922 8923 8924 </DD> 8925 8926 <DT><b><a name="smtp_tls_cert_file">smtp_tls_cert_file</a> 8927 (default: empty)</b></DT><DD> 8928 8929 <p> File with the Postfix SMTP client RSA certificate in PEM format. 8930 This file may also contain the Postfix SMTP client private RSA key, 8931 and these may be the same as the Postfix SMTP server RSA certificate and key 8932 file. </p> 8933 8934 <p> Do not configure client certificates unless you <b>must</b> present 8935 client TLS certificates to one or more servers. Client certificates are 8936 not usually needed, and can cause problems in configurations that work 8937 well without them. The recommended setting is to let the defaults stand: </p> 8938 8939 <blockquote> 8940 <pre> 8941 <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> = 8942 <a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a> = 8943 <a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> = 8944 <a href="postconf.5.html#smtp_tls_dkey_file">smtp_tls_dkey_file</a> = 8945 <a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a> = 8946 <a href="postconf.5.html#smtp_tls_eckey_file">smtp_tls_eckey_file</a> = 8947 </pre> 8948 </blockquote> 8949 8950 <p> The best way to use the default settings is to comment out the above 8951 parameters in <a href="postconf.5.html">main.cf</a> if present. </p> 8952 8953 <p> To enable remote SMTP servers to verify the Postfix SMTP client 8954 certificate, the issuing CA certificates must be made available to the 8955 server. You should include the required certificates in the client 8956 certificate file, the client certificate first, then the issuing 8957 CA(s) (bottom-up order). </p> 8958 8959 <p> Example: the certificate for "client.example.com" was issued by 8960 "intermediate CA" which itself has a certificate issued by "root CA". 8961 Create the client.pem file with "cat client_cert.pem intermediate_CA.pem 8962 root_CA.pem > client.pem". </p> 8963 8964 <p> If you also want to verify remote SMTP server certificates issued by 8965 these CAs, you can add the CA certificates to the <a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a>, in 8966 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>, 8967 <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> 8968 8969 <p> A certificate supplied here must be usable as an SSL client certificate 8970 and hence pass the "openssl verify -purpose sslclient ..." test. </p> 8971 8972 <p> Example: </p> 8973 8974 <pre> 8975 <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> = /etc/postfix/client.pem 8976 </pre> 8977 8978 <p> This feature is available in Postfix 2.2 and later. </p> 8979 8980 8981 </DD> 8982 8983 <DT><b><a name="smtp_tls_cipherlist">smtp_tls_cipherlist</a> 8984 (default: empty)</b></DT><DD> 8985 8986 <p> Obsolete Postfix < 2.3 control for the Postfix SMTP client TLS 8987 cipher list. As this feature applies to all TLS security levels, it is easy 8988 to create inter-operability problems by choosing a non-default cipher 8989 list. Do not use a non-default TLS cipher list on hosts that deliver email 8990 to the public Internet: you will be unable to send email to servers that 8991 only support the ciphers you exclude. Using a restricted cipher list 8992 may be more appropriate for an internal MTA, where one can exert some 8993 control over the TLS software and settings of the peer servers. </p> 8994 8995 <p> <b>Note:</b> do not use "" quotes around the parameter value. </p> 8996 8997 <p> This feature is available in Postfix version 2.2. It is not used with 8998 Postfix 2.3 and later; use <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> instead. </p> 8999 9000 9001 </DD> 9002 9003 <DT><b><a name="smtp_tls_ciphers">smtp_tls_ciphers</a> 9004 (default: export)</b></DT><DD> 9005 9006 <p> The minimum TLS cipher grade that the Postfix SMTP client 9007 will use with opportunistic TLS encryption. Cipher types listed in 9008 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> are excluded from the base definition of 9009 the selected cipher grade. The default value "export" ensures maximum 9010 inter-operability. Because encryption is optional, stronger controls 9011 are not appropriate, and this setting SHOULD NOT be changed unless the 9012 change is essential. </p> 9013 9014 <p> When TLS is mandatory the cipher grade is chosen via the 9015 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> configuration parameter, see there for syntax 9016 details. See <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for information on how to configure 9017 ciphers on a per-destination basis. </p> 9018 9019 <p> Example: </p> 9020 <pre> 9021 <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> = export 9022 </pre> 9023 9024 <p> This feature is available in Postfix 2.6 and later. With earlier Postfix 9025 releases only the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> parameter is implemented, 9026 and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p> 9027 9028 9029 </DD> 9030 9031 <DT><b><a name="smtp_tls_dcert_file">smtp_tls_dcert_file</a> 9032 (default: empty)</b></DT><DD> 9033 9034 <p> File with the Postfix SMTP client DSA certificate in PEM format. 9035 This file may also contain the Postfix SMTP client private DSA key. </p> 9036 9037 <p> See the discussion under <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> for more details. 9038 </p> 9039 9040 <p> Example: </p> 9041 9042 <pre> 9043 <a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> = /etc/postfix/client-dsa.pem 9044 </pre> 9045 9046 <p> This feature is available in Postfix 2.2 and later. </p> 9047 9048 9049 </DD> 9050 9051 <DT><b><a name="smtp_tls_dkey_file">smtp_tls_dkey_file</a> 9052 (default: $<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a>)</b></DT><DD> 9053 9054 <p> File with the Postfix SMTP client DSA private key in PEM format. 9055 This file may be combined with the Postfix SMTP client DSA certificate 9056 file specified with $<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a>. </p> 9057 9058 <p> The private key must be accessible without a pass-phrase, i.e. it 9059 must not be encrypted. File permissions should grant read-only 9060 access to the system superuser account ("root"), and no access 9061 to anyone else. </p> 9062 9063 <p> This feature is available in Postfix 2.2 and later. </p> 9064 9065 9066 </DD> 9067 9068 <DT><b><a name="smtp_tls_eccert_file">smtp_tls_eccert_file</a> 9069 (default: empty)</b></DT><DD> 9070 9071 <p> File with the Postfix SMTP client ECDSA certificate in PEM format. 9072 This file may also contain the Postfix SMTP client ECDSA private key. </p> 9073 9074 <p> See the discussion under <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> for more details. 9075 </p> 9076 9077 <p> Example: </p> 9078 9079 <pre> 9080 <a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a> = /etc/postfix/ecdsa-ccert.pem 9081 </pre> 9082 9083 <p> This feature is available in Postfix 2.6 and later, when Postfix is 9084 compiled and linked with OpenSSL 0.9.9 or later. </p> 9085 9086 9087 </DD> 9088 9089 <DT><b><a name="smtp_tls_eckey_file">smtp_tls_eckey_file</a> 9090 (default: $<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>)</b></DT><DD> 9091 9092 <p> File with the Postfix SMTP client ECDSA private key in PEM format. 9093 This file may be combined with the Postfix SMTP client ECDSA 9094 certificate file specified with $<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>. </p> 9095 9096 <p> The private key must be accessible without a pass-phrase, i.e. it 9097 must not be encrypted. File permissions should grant read-only 9098 access to the system superuser account ("root"), and no access 9099 to anyone else. </p> 9100 9101 <p> This feature is available in Postfix 2.6 and later, when Postfix is 9102 compiled and linked with OpenSSL 0.9.9 or later. </p> 9103 9104 9105 </DD> 9106 9107 <DT><b><a name="smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> 9108 (default: yes)</b></DT><DD> 9109 9110 <p> With mandatory TLS encryption, require that the remote SMTP 9111 server hostname matches the information in the remote SMTP server 9112 certificate. As of <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> the requirements for hostname checking 9113 for MTA clients are not specified. </p> 9114 9115 <p> This option can be set to "no" to disable strict peer name 9116 checking. This setting has no effect on sessions that are controlled 9117 via the <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> table. </p> 9118 9119 <p> Disabling the hostname verification can make sense in closed 9120 environment where special CAs are created. If not used carefully, 9121 this option opens the danger of a "man-in-the-middle" attack (the 9122 CommonName of this attacker will be logged). </p> 9123 9124 <p> This feature is available in Postfix 2.2 and later. With 9125 Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> instead. </p> 9126 9127 9128 </DD> 9129 9130 <DT><b><a name="smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> 9131 (default: empty)</b></DT><DD> 9132 9133 <p> List of ciphers or cipher types to exclude from the Postfix 9134 SMTP client cipher 9135 list at all TLS security levels. This is not an OpenSSL cipherlist, it is 9136 a simple list separated by whitespace and/or commas. The elements are a 9137 single cipher, or one or more "+" separated cipher properties, in which 9138 case only ciphers matching <b>all</b> the properties are excluded. </p> 9139 9140 <p> Examples (some of these will cause problems): </p> 9141 9142 <blockquote> 9143 <pre> 9144 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = aNULL 9145 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = MD5, DES 9146 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = DES+MD5 9147 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = AES256-SHA, DES-CBC3-MD5 9148 <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = kEDH+aRSA 9149 </pre> 9150 </blockquote> 9151 9152 <p> The first setting, disables anonymous ciphers. The next setting 9153 disables ciphers that use the MD5 digest algorithm or the (single) DES 9154 encryption algorithm. The next setting disables ciphers that use MD5 and 9155 DES together. The next setting disables the two ciphers "AES256-SHA" 9156 and "DES-CBC3-MD5". The last setting disables ciphers that use "EDH" 9157 key exchange with RSA authentication. </p> 9158 9159 <p> This feature is available in Postfix 2.3 and later. </p> 9160 9161 9162 </DD> 9163 9164 <DT><b><a name="smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> 9165 (default: empty)</b></DT><DD> 9166 9167 <p> List of acceptable remote SMTP server certificate fingerprints 9168 for the "fingerprint" TLS security level (<b><a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a></b> = 9169 fingerprint). At this security level, certificate authorities are 9170 not used, and certificate expiration times are ignored. Instead, 9171 server certificates are verified directly via their "fingerprint". The 9172 fingerprint is a message digest of the server certificate. The digest 9173 algorithm is selected via the <b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a></b> 9174 parameter. </p> 9175 9176 <p> When an <b><a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a></b> table entry specifies the 9177 "fingerprint" security level, any "match" attributes in that entry specify 9178 the list of valid fingerprints for the corresponding destination. Multiple 9179 fingerprints can be combined with a "|" delimiter in a single match 9180 attribute, or multiple match attributes can be employed. </p> 9181 9182 <p> Example: Certificate fingerprint verification with internal mailhub. 9183 Two matching fingerprints are listed. The <a href="postconf.5.html#relayhost">relayhost</a> may be multiple 9184 physical hosts behind a load-balancer, each with its own private/public 9185 key and self-signed certificate. Alternatively, a single <a href="postconf.5.html#relayhost">relayhost</a> may 9186 be in the process of switching from one set of private/public keys to 9187 another, and both keys are trusted just prior to the transition. </p> 9188 9189 <blockquote> 9190 <pre> 9191 <a href="postconf.5.html#relayhost">relayhost</a> = [mailhub.example.com] 9192 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = fingerprint 9193 <a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> = md5 9194 <a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> = 9195 3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1 9196 EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35 9197 </pre> 9198 </blockquote> 9199 9200 <p> Example: Certificate fingerprint verification with selected destinations. 9201 As in the example above, we show two matching fingerprints: </p> 9202 9203 <blockquote> 9204 <pre> 9205 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 9206 <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> = hash:/etc/postfix/tls_policy 9207 <a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> = md5 9208 </pre> 9209 </blockquote> 9210 9211 <blockquote> 9212 <pre> 9213 /etc/postfix/tls_policy: 9214 example.com fingerprint 9215 match=3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1 9216 match=EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35 9217 </pre> 9218 </blockquote> 9219 9220 <p> This feature is available in Postfix 2.5 and later. </p> 9221 9222 9223 </DD> 9224 9225 <DT><b><a name="smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> 9226 (default: md5)</b></DT><DD> 9227 9228 <p> The message digest algorithm used to construct remote SMTP server 9229 certificate fingerprints. At the "fingerprint" TLS security level 9230 (<b><a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a></b> = fingerprint), the server certificate is 9231 verified by directly matching its <i>fingerprint</i>. The fingerprint 9232 is the message digest of the server certificate using the selected 9233 algorithm. With a digest algorithm resistant to "second pre-image" 9234 attacks, it is not feasible to create a new public key and a matching 9235 certificate that has the same fingerprint. </p> 9236 9237 <p> The default algorithm is <b>md5</b>; this is consistent with 9238 the backwards compatible setting of the digest used to verify client 9239 certificates in the SMTP server. </p> 9240 9241 <p> The best practice algorithm is now <b>sha1</b>. Recent advances in hash 9242 function cryptanalysis have led to md5 being deprecated in favor of sha1. 9243 However, as long as there are no known "second pre-image" attacks 9244 against md5, its use in this context can still be considered safe. 9245 </p> 9246 9247 <p> While additional digest algorithms are often available with OpenSSL's 9248 libcrypto, only those used by libssl in SSL cipher suites are available to 9249 Postfix. For now this means just md5 or sha1. </p> 9250 9251 <p> To find the fingerprint of a specific certificate file, with a 9252 specific digest algorithm, run: 9253 </p> 9254 9255 <blockquote> 9256 <pre> 9257 $ openssl x509 -noout -fingerprint -<i>digest</i> -in <i>certfile</i>.pem 9258 </pre> 9259 </blockquote> 9260 9261 <p> The text to the right of "=" sign is the desired fingerprint. 9262 For example: </p> 9263 9264 <blockquote> 9265 <pre> 9266 $ openssl x509 -noout -fingerprint -sha1 -in cert.pem 9267 SHA1 Fingerprint=D4:6A:AB:19:24:79:F8:32:BB:A6:CB:66:82:C0:8E:9B:EE:29:A8:1A 9268 </pre> 9269 </blockquote> 9270 9271 <p> This feature is available in Postfix 2.5 and later. </p> 9272 9273 9274 </DD> 9275 9276 <DT><b><a name="smtp_tls_key_file">smtp_tls_key_file</a> 9277 (default: $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>)</b></DT><DD> 9278 9279 <p> File with the Postfix SMTP client RSA private key in PEM format. 9280 This file may be combined with the Postfix SMTP client RSA certificate 9281 file specified with $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>. </p> 9282 9283 <p> The private key must be accessible without a pass-phrase, i.e. it 9284 must not be encrypted. File permissions should grant read-only 9285 access to the system superuser account ("root"), and no access 9286 to anyone else. </p> 9287 9288 <p> Example: </p> 9289 9290 <pre> 9291 <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> 9292 </pre> 9293 9294 <p> This feature is available in Postfix 2.2 and later. </p> 9295 9296 9297 </DD> 9298 9299 <DT><b><a name="smtp_tls_loglevel">smtp_tls_loglevel</a> 9300 (default: 0)</b></DT><DD> 9301 9302 <p> Enable additional Postfix SMTP client logging of TLS activity. 9303 Each logging level also includes the information that is logged at 9304 a lower logging level. </p> 9305 9306 <dl compact> 9307 9308 <dt> </dt> <dd> 0 Disable logging of TLS activity. </dd> 9309 9310 <dt> </dt> <dd> 1 Log TLS handshake and certificate information. </dd> 9311 9312 <dt> </dt> <dd> 2 Log levels during TLS negotiation. </dd> 9313 9314 <dt> </dt> <dd> 3 Log hexadecimal and ASCII dump of TLS negotiation 9315 process. </dd> 9316 9317 <dt> </dt> <dd> 4 Log hexadecimal and ASCII dump of complete 9318 transmission after STARTTLS. </dd> 9319 9320 </dl> 9321 9322 <p> Use "<a href="postconf.5.html#smtp_tls_loglevel">smtp_tls_loglevel</a> = 3" only in case of problems. Use of 9323 loglevel 4 is strongly discouraged. </p> 9324 9325 <p> This feature is available in Postfix 2.2 and later. </p> 9326 9327 9328 </DD> 9329 9330 <DT><b><a name="smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> 9331 (default: medium)</b></DT><DD> 9332 9333 <p> The minimum TLS cipher grade that the Postfix SMTP client will 9334 use with 9335 mandatory TLS encryption. The default value "medium" is suitable 9336 for most destinations with which you may want to enforce TLS, and 9337 is beyond the reach of today's crypt-analytic methods. See 9338 <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for information on how to configure ciphers 9339 on a per-destination basis. </p> 9340 9341 <p> The following cipher grades are supported: </p> 9342 9343 <dl> 9344 <dt><b>export</b></dt> 9345 <dd> Enable the mainstream "EXPORT" grade or better OpenSSL 9346 ciphers. This is always used for opportunistic encryption. It is 9347 not recommended for mandatory encryption unless you must enforce TLS 9348 with "crippled" peers. The underlying cipherlist is specified via the 9349 <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> configuration parameter, which you are strongly 9350 encouraged to not change. The default value of <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> 9351 includes anonymous ciphers, but these are automatically filtered out if 9352 the client is configured to verify server certificates. If you must 9353 exclude anonymous ciphers also at the "encrypt" security level, set 9354 "<a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> = aNULL". </dd> 9355 9356 <dt><b>low</b></dt> 9357 <dd> Enable the mainstream "LOW" grade or better OpenSSL ciphers. This 9358 setting is only appropriate for internal mail servers. The underlying 9359 cipherlist is specified via the <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> configuration 9360 parameter, which you are strongly encouraged to not change. The default 9361 value of <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> includes anonymous ciphers, but these are 9362 automatically filtered out if the client is configured to verify server 9363 certificates. If you must exclude anonymous ciphers also at the "encrypt" 9364 security level, set "<a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> = aNULL". </dd> 9365 9366 <dt><b>medium</b></dt> 9367 <dd> Enable the mainstream "MEDIUM" grade or better OpenSSL ciphers. 9368 The underlying cipherlist is specified via the <a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> 9369 configuration parameter, which you are strongly encouraged to not change. 9370 The default value of <a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> includes anonymous ciphers, 9371 but these are automatically filtered out if the client is configured to 9372 verify server certificates. If you must exclude anonymous ciphers also 9373 at the "encrypt" security level, set "<a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> 9374 = aNULL". </dd> 9375 9376 <dt><b>high</b></dt> 9377 <dd> Enable only the mainstream "HIGH" grade OpenSSL ciphers. This 9378 setting is appropriate when all mandatory TLS destinations support 9379 some of "HIGH" grade ciphers, this is not uncommon. The underlying 9380 cipherlist is specified via the <a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a> configuration 9381 parameter, which you are strongly encouraged to not change. The default 9382 value of <a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a> includes anonymous ciphers, but these are 9383 automatically filtered out if the client is configured to verify server 9384 certificates. If you must exclude anonymous ciphers also at the "encrypt" 9385 security level, set "<a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> = aNULL". </dd> 9386 9387 <dt><b>null</b></dt> 9388 <dd> Enable only the "NULL" OpenSSL ciphers, these provide authentication 9389 without encryption. This setting is only appropriate in the rare case 9390 that all servers are prepared to use NULL ciphers (not normally enabled 9391 in TLS servers). A plausible use-case is an LMTP server listening on a 9392 UNIX-domain socket that is configured to support "NULL" ciphers. The 9393 underlying cipherlist is specified via the <a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a> 9394 configuration parameter, which you are strongly encouraged to not 9395 change. The default value of <a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a> excludes anonymous 9396 ciphers (OpenSSL 0.9.8 has NULL ciphers that offer data integrity without 9397 encryption or authentication). </dd> 9398 9399 </dl> 9400 9401 <p> This feature is available in Postfix 2.3 and later. </p> 9402 9403 9404 </DD> 9405 9406 <DT><b><a name="smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> 9407 (default: empty)</b></DT><DD> 9408 9409 <p> Additional list of ciphers or cipher types to exclude from the 9410 SMTP client cipher list at mandatory TLS security levels. This list 9411 works in addition to the exclusions listed with <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> 9412 (see there for syntax details). </p> 9413 9414 <p> Starting with Postfix 2.6, the mandatory cipher exclusions can be 9415 specified on a per-destination basis via the TLS policy "exclude" 9416 attribute. See <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for notes and examples. </p> 9417 9418 <p> This feature is available in Postfix 2.3 and later. </p> 9419 9420 9421 </DD> 9422 9423 <DT><b><a name="smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> 9424 (default: SSLv3, TLSv1)</b></DT><DD> 9425 9426 <p> List of SSL/TLS protocols that the Postfix SMTP client will use with 9427 mandatory TLS encryption. In <a href="postconf.5.html">main.cf</a> the values are separated by 9428 whitespace, commas or colons. In the policy table "protocols" attribute 9429 (see <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) the only valid separator is colon. An 9430 empty value means allow all protocols. The valid protocol names, (see 9431 <b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" and "TLSv1". </p> 9432 9433 <p> With Postfix ≥ 2.5 the parameter syntax is expanded to support 9434 protocol exclusions. One can now explicitly exclude SSLv2 by setting 9435 "<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2". To exclude both SSLv2 and 9436 SSLv3 set "<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !SSLv3". Listing 9437 the protocols to include, rather than protocols to exclude, is still 9438 supported; use the form you find more intuitive. </p> 9439 9440 <p> Since SSL version 2 has known protocol weaknesses and is now 9441 deprecated, the default setting excludes "SSLv2". This means that by 9442 default, SSL version 2 will not be used at the "encrypt" security level 9443 and higher. </p> 9444 9445 <p> See the documentation of the <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> parameter and 9446 <a href="TLS_README.html">TLS_README</a> for more information about security levels. </p> 9447 9448 <p> Example: </p> 9449 9450 <pre> 9451 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = TLSv1 9452 # Alternative form with Postfix ≥ 2.5: 9453 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !SSLv3 9454 </pre> 9455 9456 <p> This feature is available in Postfix 2.3 and later. </p> 9457 9458 9459 </DD> 9460 9461 <DT><b><a name="smtp_tls_note_starttls_offer">smtp_tls_note_starttls_offer</a> 9462 (default: no)</b></DT><DD> 9463 9464 <p> Log the hostname of a remote SMTP server that offers STARTTLS, 9465 when TLS is not already enabled for that server. </p> 9466 9467 <p> The logfile record looks like: </p> 9468 9469 <pre> 9470 postfix/smtp[pid]: Host offered STARTTLS: [name.of.host] 9471 </pre> 9472 9473 <p> This feature is available in Postfix 2.2 and later. </p> 9474 9475 9476 </DD> 9477 9478 <DT><b><a name="smtp_tls_per_site">smtp_tls_per_site</a> 9479 (default: empty)</b></DT><DD> 9480 9481 <p> Optional lookup tables with the Postfix SMTP client TLS usage 9482 policy by next-hop destination and by remote SMTP server hostname. 9483 When both lookups succeed, the more specific per-site policy (NONE, 9484 MUST, etc) overrides the less specific one (MAY), and the more secure 9485 per-site policy (MUST, etc) overrides the less secure one (NONE). 9486 With Postfix 2.3 and later <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> is strongly discouraged: 9487 use <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> instead. </p> 9488 9489 <p> Use of the bare hostname as the per-site table lookup key is 9490 discouraged. Always use the full destination nexthop (enclosed in 9491 [] with a possible ":port" suffix). A recipient domain or MX-enabled 9492 transport next-hop with no port suffix may look like a bare hostname, 9493 but is still a suitable <i>destination</i>. </p> 9494 9495 <p> Specify a next-hop destination or server hostname on the left-hand 9496 side; no wildcards are allowed. The next-hop destination is either 9497 the recipient domain, or the destination specified with a <a href="transport.5.html">transport(5)</a> 9498 table, the <a href="postconf.5.html#relayhost">relayhost</a> parameter, or the <a href="postconf.5.html#relay_transport">relay_transport</a> parameter. 9499 On the right hand side specify one of the following keywords: </p> 9500 9501 <dl> 9502 9503 <dt> NONE </dt> <dd> Don't use TLS at all. This overrides a less 9504 specific <b>MAY</b> lookup result from the alternate host or next-hop 9505 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>, 9506 and <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> settings. </dd> 9507 9508 <dt> MAY </dt> <dd> Try to use TLS if the server announces support, 9509 otherwise use the unencrypted connection. This has less precedence 9510 than a more specific result (including <b>NONE</b>) from the alternate 9511 host or next-hop lookup key, and has less precedence than the more 9512 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> 9513 = yes". </dd> 9514 9515 <dt> MUST_NOPEERMATCH </dt> <dd> Require TLS encryption, but do not 9516 require that the remote SMTP server hostname matches the information 9517 in the remote SMTP server certificate, or that the server certificate 9518 was issued by a trusted CA. This overrides a less secure <b>NONE</b> 9519 or a less specific <b>MAY</b> lookup result from the alternate host 9520 or next-hop lookup key, and overrides the global <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>, 9521 <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> 9522 9523 <dt> MUST </dt> <dd> Require TLS encryption, require that the remote 9524 SMTP server hostname matches the information in the remote SMTP 9525 server certificate, and require that the remote SMTP server certificate 9526 was issued by a trusted CA. This overrides a less secure <b>NONE</b> 9527 and <b>MUST_NOPEERMATCH</b> or a less specific <b>MAY</b> lookup 9528 result from the alternate host or next-hop lookup key, and overrides 9529 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> 9530 settings. </dd> 9531 9532 </dl> 9533 9534 <p> The above keywords correspond to the "none", "may", "encrypt" and 9535 "verify" security levels for the new <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> parameter 9536 introduced in Postfix 2.3. Starting with Postfix 2.3, and independently 9537 of how the policy is specified, the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and 9538 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> parameters apply when TLS encryption 9539 is mandatory. Connections for which encryption is optional typically 9540 enable all "export" grade and better ciphers (see <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> 9541 and <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>). </p> 9542 9543 <p> As long as no secure DNS lookup mechanism is available, false 9544 hostnames in MX or CNAME responses can change the server hostname 9545 that Postfix uses for TLS policy lookup and server certificate 9546 verification. Even with a perfect match between the server hostname and 9547 the server certificate, there is no guarantee that Postfix is connected 9548 to the right server. See <a href="TLS_README.html">TLS_README</a> (Closing a DNS loophole with obsolete 9549 per-site TLS policies) for a possible work-around. </p> 9550 9551 <p> This feature is available in Postfix 2.2 and later. With 9552 Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> instead. </p> 9553 9554 9555 </DD> 9556 9557 <DT><b><a name="smtp_tls_policy_maps">smtp_tls_policy_maps</a> 9558 (default: empty)</b></DT><DD> 9559 9560 <p> Optional lookup tables with the Postfix SMTP client TLS security 9561 policy by next-hop destination; when a non-empty value is specified, 9562 this overrides the obsolete <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> parameter. See 9563 <a href="TLS_README.html">TLS_README</a> for a more detailed discussion of TLS security levels. 9564 </p> 9565 9566 <p> The TLS policy table is indexed by the full next-hop destination, 9567 which is either the recipient domain, or the verbatim next-hop 9568 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>, 9569 $<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 9570 square brackets and any non-default destination server port suffix. The 9571 LMTP socket type prefix (inet: or unix:) is not included in the lookup 9572 key. </p> 9573 9574 <p> Only the next-hop domain, or $<a href="postconf.5.html#myhostname">myhostname</a> with LMTP over UNIX-domain 9575 sockets, is used as the nexthop name for certificate verification. The 9576 port and any enclosing square brackets are used in the table lookup key, 9577 but are not used for server name verification. </p> 9578 9579 <p> When the lookup key is a domain name without enclosing square brackets 9580 or any <i>:port</i> suffix (typically the recipient domain), and the full 9581 domain is not found in the table, just as with the <a href="transport.5.html">transport(5)</a> table, 9582 the parent domain starting with a leading "." is matched recursively. This 9583 allows one to specify a security policy for a recipient domain and all 9584 its sub-domains. </p> 9585 9586 <p> The lookup result is a security level, followed by an optional list 9587 of whitespace and/or comma separated name=value attributes that override 9588 related <a href="postconf.5.html">main.cf</a> settings. The TLS security levels in order of increasing 9589 security are: </p> 9590 9591 <dl> 9592 9593 <dt><b>none</b></dt> 9594 <dd>No TLS. No additional attributes are supported at this level. </dd> 9595 9596 <dt><b>may</b></dt> 9597 <dd>Opportunistic TLS. Since sending in the clear is acceptable, 9598 demanding stronger than default TLS security merely reduces 9599 inter-operability. The optional "ciphers", "exclude" and "protocols" 9600 attributes (available for opportunistic TLS with Postfix ≥ 2.6) 9601 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 9602 "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>" configuration parameters. When opportunistic TLS 9603 handshakes fail, Postfix retries the connection with TLS disabled. 9604 This allows mail delivery to sites with non-interoperable TLS 9605 implementations.</dd> 9606 9607 <dt><b>encrypt</b></dt> <dd>Mandatory TLS encryption. At this level 9608 and higher, the optional "protocols" attribute overrides the <a href="postconf.5.html">main.cf</a> 9609 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> parameter, the optional "ciphers" attribute 9610 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 9611 optional "exclude" attribute (Postfix ≥ 2.6) overrides the <a href="postconf.5.html">main.cf</a> 9612 <a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> parameter. In the policy table, 9613 multiple protocols or excluded ciphers must be separated by colons, 9614 as attribute values may not contain whitespace or commas. </dd> 9615 9616 <dt><b>fingerprint</b></dt> <dd>Certificate fingerprint 9617 verification. Available with Postfix 2.5 and later. At this security 9618 level, there are no trusted certificate authorities. The certificate 9619 trust chain, expiration date, ... are not checked. Instead, 9620 the optional <b>match</b> attribute, or else the <a href="postconf.5.html">main.cf</a> 9621 <b><a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a></b> parameter, lists the 9622 valid "fingerprints" of the server certificate. The digest 9623 algorithm used to calculate the fingerprint is selected by the 9624 <b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a></b> parameter. Multiple fingerprints can 9625 be combined with a "|" delimiter in a single match attribute, or multiple 9626 match attributes can be employed. The ":" character is not used as a 9627 delimiter as it occurs between each pair of fingerprint (hexadecimal) 9628 digits. </dd> 9629 9630 <dt><b>verify</b></dt> <dd>Mandatory TLS verification. At this security 9631 level, DNS MX lookups are trusted to be secure enough, and the name 9632 verified in the server certificate is usually obtained indirectly via 9633 unauthenticated DNS MX lookups. The optional "match" attribute overrides 9634 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, 9635 multiple match patterns and strategies must be separated by colons. 9636 In practice explicit control over matching is more common with the 9637 "secure" policy, described below. </dd> 9638 9639 <dt><b>secure</b></dt> <dd>Secure-channel TLS. At this security level, DNS 9640 MX lookups, though potentially used to determine the candidate next-hop 9641 gateway IP addresses, are <b>not</b> trusted to be secure enough for TLS 9642 peername verification. Instead, the default name verified in the server 9643 certificate is obtained directly from the next-hop, or is explicitly 9644 specified via the optional <b>match</b> attribute which overrides the 9645 <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, 9646 multiple match patterns and strategies must be separated by colons. 9647 The match attribute is most useful when multiple domains are supported by 9648 common server, the policy entries for additional domains specify matching 9649 rules for the primary domain certificate. While transport table overrides 9650 routing the secondary domains to the primary nexthop also allow secure 9651 verification, they risk delivery to the wrong destination when domains 9652 change hands or are re-assigned to new gateways. With the "match" 9653 attribute approach, routing is not perturbed, and mail is deferred if 9654 verification of a new MX host fails. </dd> 9655 9656 </dl> 9657 9658 <p> 9659 Example: 9660 </p> 9661 9662 <pre> 9663 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 9664 <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> = hash:/etc/postfix/tls_policy 9665 # Postfix 2.5 and later 9666 <a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> = md5 9667 </pre> 9668 9669 <pre> 9670 /etc/postfix/tls_policy: 9671 example.edu none 9672 example.mil may 9673 example.gov encrypt protocols=TLSv1 9674 example.com verify ciphers=high 9675 example.net secure 9676 .example.net secure match=.example.net:example.net 9677 [mail.example.org]:587 secure match=nexthop 9678 # Postfix 2.5 and later 9679 [thumb.example.org] fingerprint 9680 match=EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35 9681 match=3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1 9682 </pre> 9683 9684 <p> <b>Note:</b> The <b>hostname</b> strategy if listed in a non-default 9685 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 9686 in the policy table can render the <b>secure</b> level vulnerable to 9687 DNS forgery. Do not use the <b>hostname</b> strategy for secure-channel 9688 configurations in environments where DNS security is not assured. </p> 9689 9690 <p> This feature is available in Postfix 2.3 and later. </p> 9691 9692 9693 </DD> 9694 9695 <DT><b><a name="smtp_tls_protocols">smtp_tls_protocols</a> 9696 (default: !SSLv2)</b></DT><DD> 9697 9698 <p> List of TLS protocols that the Postfix SMTP client will exclude or 9699 include with opportunistic TLS encryption. Starting with Postfix 2.6, 9700 the Postfix SMTP client will by default not use the obsolete SSLv2 9701 protocol. </p> 9702 9703 <p> In <a href="postconf.5.html">main.cf</a> the values are separated by whitespace, commas or 9704 colons. In the policy table (see <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) the only valid 9705 separator is colon. An empty value means allow all protocols. The valid 9706 protocol names, (see <b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" 9707 and "TLSv1". </p> 9708 9709 <p> To include a protocol list its name, to exclude it, prefix the name 9710 with a "!" character. To exclude SSLv2 even for opportunistic TLS set 9711 "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2". To exclude both "SSLv2" and "SSLv3" set 9712 "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2, !SSLv3". Explicitly listing the protocols to 9713 include, is supported, but not recommended. OpenSSL provides no mechanisms 9714 for excluding protocols not known at compile-time. If Postfix is linked 9715 against an OpenSSL library that supports additional protocol versions, 9716 they cannot be excluded using either syntax. </p> 9717 9718 <p> Example: </p> 9719 <pre> 9720 # TLSv1 only! 9721 <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2, !SSLv3 9722 </pre> 9723 9724 <p> This feature is available in Postfix 2.6 and later. </p> 9725 9726 9727 </DD> 9728 9729 <DT><b><a name="smtp_tls_scert_verifydepth">smtp_tls_scert_verifydepth</a> 9730 (default: 9)</b></DT><DD> 9731 9732 <p> The verification depth for remote SMTP server certificates. A depth 9733 of 1 is sufficient if the issuing CA is listed in a local CA file. </p> 9734 9735 <p> The default verification depth is 9 (the OpenSSL default) for 9736 compatibility with earlier Postfix behavior. Prior to Postfix 2.5, 9737 the default value was 5, but the limit was not actually enforced. If 9738 you have set this to a lower non-default value, certificates with longer 9739 trust chains may now fail to verify. Certificate chains with 1 or 2 9740 CAs are common, deeper chains are more rare and any number between 5 9741 and 9 should suffice in practice. You can choose a lower number if, 9742 for example, you trust certificates directly signed by an issuing CA 9743 but not any CAs it delegates to. </p> 9744 9745 <p> This feature is available in Postfix 2.2 and later. </p> 9746 9747 9748 </DD> 9749 9750 <DT><b><a name="smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> 9751 (default: nexthop, dot-nexthop)</b></DT><DD> 9752 9753 <p> The server certificate peername verification method for the 9754 "secure" TLS security level. In a "secure" TLS policy table 9755 ($<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) entry the optional "match" attribute 9756 overrides this <a href="postconf.5.html">main.cf</a> setting. </p> 9757 9758 <p> This parameter specifies one or more patterns or strategies separated 9759 by commas, whitespace or colons. In the policy table the only valid 9760 separator is the colon character. </p> 9761 9762 <p> For a description of the pattern and strategy syntax see the 9763 <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> parameter. The "hostname" strategy should 9764 be avoided in this context, as in the absence of a secure global DNS, using 9765 the results of MX lookups in certificate verification is not immune to active 9766 (man-in-the-middle) attacks on DNS. </p> 9767 9768 <p> 9769 Sample <a href="postconf.5.html">main.cf</a> setting: 9770 </p> 9771 9772 <blockquote> 9773 <pre> 9774 <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> = nexthop 9775 </pre> 9776 </blockquote> 9777 9778 <p> 9779 Sample policy table override: 9780 </p> 9781 9782 <blockquote> 9783 <pre> 9784 example.net secure match=example.com:.example.com 9785 .example.net secure match=example.com:.example.com 9786 </pre> 9787 </blockquote> 9788 9789 <p> This feature is available in Postfix 2.3 and later. </p> 9790 9791 9792 </DD> 9793 9794 <DT><b><a name="smtp_tls_security_level">smtp_tls_security_level</a> 9795 (default: empty)</b></DT><DD> 9796 9797 <p> The default SMTP TLS security level for the Postfix SMTP client; 9798 when a non-empty value is specified, this overrides the obsolete 9799 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>. 9800 </p> 9801 9802 <p> Specify one of the following security levels: </p> 9803 9804 <dl> 9805 9806 <dt><b>none</b></dt> <dd> TLS will not be used unless enabled for specific 9807 destinations via <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>. </dd> 9808 9809 <dt><b>may</b></dt> 9810 <dd> Opportunistic TLS. Use TLS if this is supported by the remote 9811 SMTP server, otherwise use plaintext. Since 9812 sending in the clear is acceptable, demanding stronger than default TLS 9813 security merely reduces inter-operability. 9814 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) 9815 configuration parameters provide control over the protocols and 9816 cipher grade used with opportunistic TLS. With earlier releases the 9817 opportunistic TLS cipher grade is always "export" and no protocols 9818 are disabled. 9819 When TLS handshakes fail, the connection is retried with TLS disabled. 9820 This allows mail delivery to sites with non-interoperable TLS 9821 implementations. </dd> 9822 9823 <dt><b>encrypt</b></dt> <dd>Mandatory TLS encryption. Since a minimum 9824 level of security is intended, it is reasonable to be specific about 9825 sufficiently secure protocol versions and ciphers. At this security level 9826 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 9827 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> specify the TLS protocols and minimum 9828 cipher grade which the administrator considers secure enough for 9829 mandatory encrypted sessions. This security level is not an appropriate 9830 default for systems delivering mail to the Internet. </dd> 9831 9832 <dt><b>fingerprint</b></dt> <dd>Certificate fingerprint 9833 verification. Available with Postfix 2.5 and later. At this security 9834 level, there are no trusted certificate authorities. The certificate 9835 trust chain, expiration date, ... are not checked. Instead, 9836 the <b><a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a></b> parameter lists 9837 the valid "fingerprints" of the server certificate. The digest 9838 algorithm used to calculate the fingerprint is selected by the 9839 <b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a></b> parameter. </dd> 9840 9841 <dt><b>verify</b></dt> <dd>Mandatory TLS verification. At this security 9842 level, DNS MX lookups are trusted to be secure enough, and the name 9843 verified in the server certificate is usually obtained indirectly 9844 via unauthenticated DNS MX lookups. The <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> 9845 parameter controls how the server name is verified. In practice explicit 9846 control over matching is more common at the "secure" level, described 9847 below. This security level is not an appropriate default for systems 9848 delivering mail to the Internet. </dd> 9849 9850 <dt><b>secure</b></dt> <dd>Secure-channel TLS. At this security level, 9851 DNS MX lookups, though potentially used to determine the candidate 9852 next-hop gateway IP addresses, are <b>not</b> trusted to be secure enough 9853 for TLS peername verification. Instead, the default name verified in 9854 the server certificate is obtained from the next-hop domain as specified 9855 in the <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> configuration parameter. The default 9856 matching rule is that a server certificate matches when its name is equal 9857 to or is a sub-domain of the nexthop domain. This security level is not 9858 an appropriate default for systems delivering mail to the Internet. </dd> 9859 9860 </dl> 9861 9862 <p> 9863 Examples: 9864 </p> 9865 9866 <pre> 9867 # 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. 9868 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = none 9869 </pre> 9870 9871 <pre> 9872 # Opportunistic TLS. 9873 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = may 9874 # Postfix ≥ 2.6: 9875 # Do not tweak opportunistic ciphers unless it is essential 9876 # to do so (if a security vulnerability is found in the SSL library that 9877 # can be mitigated by disabling a particular protocol or raising the 9878 # cipher grade from "export" to "low" or "medium"). 9879 <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> = export 9880 <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2 9881 </pre> 9882 9883 <pre> 9884 # Mandatory (high-grade) TLS encryption. 9885 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = encrypt 9886 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high 9887 </pre> 9888 9889 <pre> 9890 # Mandatory TLS verification of hostname or nexthop domain. 9891 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = verify 9892 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high 9893 <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> = hostname, nexthop, dot-nexthop 9894 </pre> 9895 9896 <pre> 9897 # Secure channel TLS with exact nexthop name match. 9898 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = secure 9899 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = TLSv1 9900 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high 9901 <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> = nexthop 9902 </pre> 9903 9904 <pre> 9905 # Certificate fingerprint verification (Postfix ≥ 2.5). 9906 # The CA-less "fingerprint" security level only scales to a limited 9907 # number of destinations. As a global default rather than a per-site 9908 # setting, this is practical when mail for all recipients is sent 9909 # to a central mail hub. 9910 <a href="postconf.5.html#relayhost">relayhost</a> = [mailhub.example.com] 9911 <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = fingerprint 9912 <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !SSLv3 9913 <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high 9914 <a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> = 9915 3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1 9916 EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35 9917 </pre> 9918 9919 <p> This feature is available in Postfix 2.3 and later. </p> 9920 9921 9922 </DD> 9923 9924 <DT><b><a name="smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> 9925 (default: empty)</b></DT><DD> 9926 9927 <p> Name of the file containing the optional Postfix SMTP client 9928 TLS session cache. Specify a database type that supports enumeration, 9929 such as <b>btree</b> or <b>sdbm</b>; there is no need to support 9930 concurrent access. The file is created if it does not exist. The <a href="smtp.8.html">smtp(8)</a> 9931 daemon does not use this parameter directly, rather the cache is 9932 implemented indirectly in the <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon. This means that 9933 per-smtp-instance <a href="master.5.html">master.cf</a> overrides of this parameter are not effective. 9934 Note, that each of the cache databases supported by <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon: 9935 $<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> 9936 (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 9937 be stored separately. It is not at this time possible to store multiple 9938 caches in a single database. </p> 9939 9940 <p> Note: <b>dbm</b> databases are not suitable. TLS 9941 session objects are too large. </p> 9942 9943 <p> As of version 2.5, Postfix no longer uses root privileges when 9944 opening this file. The file should now be stored under the Postfix-owned 9945 <a href="postconf.5.html#data_directory">data_directory</a>. As a migration aid, an attempt to open the file 9946 under a non-Postfix directory is redirected to the Postfix-owned 9947 <a href="postconf.5.html#data_directory">data_directory</a>, and a warning is logged. </p> 9948 9949 <p> Example: </p> 9950 9951 <pre> 9952 <a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> = btree:/var/lib/postfix/smtp_scache 9953 </pre> 9954 9955 <p> This feature is available in Postfix 2.2 and later. </p> 9956 9957 9958 </DD> 9959 9960 <DT><b><a name="smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a> 9961 (default: 3600s)</b></DT><DD> 9962 9963 <p> The expiration time of Postfix SMTP client TLS session cache 9964 information. A cache cleanup is performed periodically 9965 every $<a href="postconf.5.html#smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a> seconds. As with 9966 $<a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a>, this parameter is implemented in the 9967 <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon and therefore per-smtp-instance <a href="master.5.html">master.cf</a> overrides 9968 are not possible. </p> 9969 9970 <p> This feature is available in Postfix 2.2 and later. </p> 9971 9972 9973 </DD> 9974 9975 <DT><b><a name="smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> 9976 (default: hostname)</b></DT><DD> 9977 9978 <p> The server certificate peername verification method for the 9979 "verify" TLS security level. In a "verify" TLS policy table 9980 ($<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) entry the optional "match" attribute 9981 overrides this <a href="postconf.5.html">main.cf</a> setting. </p> 9982 9983 <p> This parameter specifies one or more patterns or strategies separated 9984 by commas, whitespace or colons. In the policy table the only valid 9985 separator is the colon character. </p> 9986 9987 <p> Patterns specify domain names, or domain name suffixes: </p> 9988 9989 <dl> 9990 9991 <dt><i>example.com</i></dt> <dd> Match the <i>example.com</i> domain, 9992 i.e. one of the names the server certificate must be <i>example.com</i>, 9993 upper and lower case distinctions are ignored. </dd> 9994 9995 <dt><i>.example.com</i></dt> 9996 <dd> Match subdomains of the <i>example.com</i> domain, i.e. match 9997 a name in the server certificate that consists of a non-zero number of 9998 labels followed by a <i>.example.com</i> suffix. Case distinctions are 9999 ignored.</dd> 10000 10001 </dl> 10002 10003 <p> Strategies specify a transformation from the next-hop domain 10004 to the expected name in the server certificate: </p> 10005 10006 <dl> 10007 10008 <dt>nexthop</dt> 10009 <dd> Match against the next-hop domain, which is either the recipient 10010 domain, or the transport next-hop configured for the domain stripped of 10011 any optional socket type prefix, enclosing square brackets and trailing 10012 port. When MX lookups are not suppressed, this is the original nexthop 10013 domain prior to the MX lookup, not the result of the MX lookup. For 10014 LMTP delivery via UNIX-domain sockets, the verified next-hop name is 10015 $<a href="postconf.5.html#myhostname">myhostname</a>. This strategy is suitable for use with the "secure" 10016 policy. Case is ignored.</dd> 10017 10018 <dt>dot-nexthop</dt> 10019 <dd> As above, but match server certificate names that are subdomains 10020 of the next-hop domain. Case is ignored.</dd> 10021 10022 <dt>hostname</dt> <dd> Match against the hostname of the server, often 10023 obtained via an unauthenticated DNS MX lookup. For LMTP delivery via 10024 UNIX-domain sockets, the verified name is $<a href="postconf.5.html#myhostname">myhostname</a>. This matches 10025 the verification strategy of the "MUST" keyword in the obsolete 10026 <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> table, and is suitable for use with the "verify" 10027 security level. When the next-hop name is enclosed in square brackets 10028 to suppress MX lookups, the "hostname" strategy is the same as the 10029 "nexthop" strategy. Case is ignored.</dd> 10030 10031 </dl> 10032 10033 <p> 10034 Sample <a href="postconf.5.html">main.cf</a> setting: 10035 </p> 10036 10037 <pre> 10038 <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> = hostname, nexthop, dot-nexthop 10039 </pre> 10040 10041 <p> 10042 Sample policy table override: 10043 </p> 10044 10045 <pre> 10046 example.com verify match=hostname:nexthop 10047 .example.com verify match=example.com:.example.com:hostname 10048 </pre> 10049 10050 <p> This feature is available in Postfix 2.3 and later. </p> 10051 10052 10053 </DD> 10054 10055 <DT><b><a name="smtp_use_tls">smtp_use_tls</a> 10056 (default: no)</b></DT><DD> 10057 10058 <p> Opportunistic mode: use TLS when a remote SMTP server announces 10059 STARTTLS support, otherwise send the mail in the clear. Beware: 10060 some SMTP servers offer STARTTLS even if it is not configured. With 10061 Postfix < 2.3, if the TLS handshake fails, and no other server is 10062 available, delivery is deferred and mail stays in the queue. If this 10063 is a concern for you, use the <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> feature instead. </p> 10064 10065 <p> This feature is available in Postfix 2.2 and later. With 10066 Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> instead. </p> 10067 10068 10069 </DD> 10070 10071 <DT><b><a name="smtp_xforward_timeout">smtp_xforward_timeout</a> 10072 (default: 300s)</b></DT><DD> 10073 10074 <p> 10075 The SMTP client time limit for sending the XFORWARD command, and 10076 for receiving the server response. 10077 </p> 10078 10079 <p> 10080 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 10081 The default time unit is s (seconds). 10082 </p> 10083 10084 <p> 10085 This feature is available in Postfix 2.1 and later. 10086 </p> 10087 10088 10089 </DD> 10090 10091 <DT><b><a name="smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a> 10092 (default: $<a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a>)</b></DT><DD> 10093 10094 <p> What SMTP clients are allowed to specify the XVERP command. 10095 This command requests that mail be delivered one recipient at a 10096 time with a per recipient return address. </p> 10097 10098 <p> By default, no clients are allowed to specify XVERP. </p> 10099 10100 <p> This parameter was renamed with Postfix version 2.1. The default value 10101 is backwards compatible with Postfix version 2.0. </p> 10102 10103 <p> Specify a list of network/netmask patterns, separated by commas 10104 and/or whitespace. The mask specifies the number of bits in the 10105 network part of a host address. You can also specify hostnames or 10106 .domain names (the initial dot causes the domain to match any name 10107 below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" 10108 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 10109 is matched when a table entry matches a lookup string (the lookup 10110 result is ignored). Continue long lines by starting the next line 10111 with whitespace. Specify "!pattern" to exclude an address or network 10112 block from the list. The form "!/file/name" is supported only in 10113 Postfix version 2.4 and later. </p> 10114 10115 <p> Note: IP version 6 address information must be specified inside 10116 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a> value, and in 10117 files specified with "/file/name". IP version 6 addresses contain 10118 the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 10119 pattern. </p> 10120 10121 10122 </DD> 10123 10124 <DT><b><a name="smtpd_authorized_xclient_hosts">smtpd_authorized_xclient_hosts</a> 10125 (default: empty)</b></DT><DD> 10126 10127 <p> 10128 What SMTP clients are allowed to use the XCLIENT feature. This 10129 command overrides SMTP client information that is used for access 10130 control. Typical use is for SMTP-based content filters, fetchmail-like 10131 programs, or SMTP server access rule testing. See the <a href="XCLIENT_README.html">XCLIENT_README</a> 10132 document for details. 10133 </p> 10134 10135 <p> 10136 This feature is available in Postfix 2.1 and later. 10137 </p> 10138 10139 <p> 10140 By default, no clients are allowed to specify XCLIENT. 10141 </p> 10142 10143 <p> 10144 Specify a list of network/netmask patterns, separated by commas 10145 and/or whitespace. The mask specifies the number of bits in the 10146 network part of a host address. You can also specify hostnames or 10147 .domain names (the initial dot causes the domain to match any name 10148 below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" 10149 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 10150 is matched when a table entry matches a lookup string (the lookup 10151 result is ignored). Continue long lines by starting the next line 10152 with whitespace. Specify "!pattern" to exclude an address or network 10153 block from the list. The form "!/file/name" is supported only in 10154 Postfix version 2.4 and later. </p> 10155 10156 <p> Note: IP version 6 address information must be specified inside 10157 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_authorized_xclient_hosts">smtpd_authorized_xclient_hosts</a> value, and in 10158 files specified with "/file/name". IP version 6 addresses contain 10159 the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 10160 pattern. </p> 10161 10162 10163 </DD> 10164 10165 <DT><b><a name="smtpd_authorized_xforward_hosts">smtpd_authorized_xforward_hosts</a> 10166 (default: empty)</b></DT><DD> 10167 10168 <p> 10169 What SMTP clients are allowed to use the XFORWARD feature. This 10170 command forwards information that is used to improve logging after 10171 SMTP-based content filters. See the <a href="XFORWARD_README.html">XFORWARD_README</a> document for 10172 details. 10173 </p> 10174 10175 <p> 10176 This feature is available in Postfix 2.1 and later. 10177 </p> 10178 10179 <p> 10180 By default, no clients are allowed to specify XFORWARD. 10181 </p> 10182 10183 <p> 10184 Specify a list of network/netmask patterns, separated by commas 10185 and/or whitespace. The mask specifies the number of bits in the 10186 network part of a host address. You can also specify hostnames or 10187 .domain names (the initial dot causes the domain to match any name 10188 below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" 10189 pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table 10190 is matched when a table entry matches a lookup string (the lookup 10191 result is ignored). Continue long lines by starting the next line 10192 with whitespace. Specify "!pattern" to exclude an address or network 10193 block from the list. The form "!/file/name" is supported only in 10194 Postfix version 2.4 and later. </p> 10195 10196 <p> Note: IP version 6 address information must be specified inside 10197 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_authorized_xforward_hosts">smtpd_authorized_xforward_hosts</a> value, and in 10198 files specified with "/file/name". IP version 6 addresses contain 10199 the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 10200 pattern. </p> 10201 10202 10203 </DD> 10204 10205 <DT><b><a name="smtpd_banner">smtpd_banner</a> 10206 (default: $<a href="postconf.5.html#myhostname">myhostname</a> ESMTP $<a href="postconf.5.html#mail_name">mail_name</a>)</b></DT><DD> 10207 10208 <p> 10209 The text that follows the 220 status code in the SMTP greeting 10210 banner. Some people like to see the mail version advertised. By 10211 default, Postfix shows no version. 10212 </p> 10213 10214 <p> 10215 You MUST specify $<a href="postconf.5.html#myhostname">myhostname</a> at the start of the text. This is 10216 required by the SMTP protocol. 10217 </p> 10218 10219 <p> 10220 Example: 10221 </p> 10222 10223 <pre> 10224 <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>) 10225 </pre> 10226 10227 10228 </DD> 10229 10230 <DT><b><a name="smtpd_client_connection_count_limit">smtpd_client_connection_count_limit</a> 10231 (default: 50)</b></DT><DD> 10232 10233 <p> 10234 How many simultaneous connections any client is allowed to 10235 make to this service. By default, the limit is set to half 10236 the default process limit value. 10237 </p> 10238 10239 <p> 10240 To disable this feature, specify a limit of 0. 10241 </p> 10242 10243 <p> 10244 WARNING: The purpose of this feature is to limit abuse. It must 10245 not be used to regulate legitimate mail traffic. 10246 </p> 10247 10248 <p> 10249 This feature is available in Postfix 2.2 and later. 10250 </p> 10251 10252 10253 </DD> 10254 10255 <DT><b><a name="smtpd_client_connection_rate_limit">smtpd_client_connection_rate_limit</a> 10256 (default: 0)</b></DT><DD> 10257 10258 <p> 10259 The maximal number of connection attempts any client is allowed to 10260 make to this service per time unit. The time unit is specified 10261 with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter. 10262 </p> 10263 10264 <p> 10265 By default, a client can make as many connections per time unit as 10266 Postfix can accept. 10267 </p> 10268 10269 <p> 10270 To disable this feature, specify a limit of 0. 10271 </p> 10272 10273 <p> 10274 WARNING: The purpose of this feature is to limit abuse. It must 10275 not be used to regulate legitimate mail traffic. 10276 </p> 10277 10278 <p> 10279 This feature is available in Postfix 2.2 and later. 10280 </p> 10281 10282 <p> 10283 Example: 10284 </p> 10285 10286 <pre> 10287 <a href="postconf.5.html#smtpd_client_connection_rate_limit">smtpd_client_connection_rate_limit</a> = 1000 10288 </pre> 10289 10290 10291 </DD> 10292 10293 <DT><b><a name="smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a> 10294 (default: $<a href="postconf.5.html#mynetworks">mynetworks</a>)</b></DT><DD> 10295 10296 <p> 10297 Clients that are excluded from connection count, connection rate, 10298 or SMTP request rate restrictions. See the <a href="postconf.5.html#mynetworks">mynetworks</a> parameter 10299 description for the parameter value syntax. 10300 </p> 10301 10302 <p> 10303 By default, clients in trusted networks are excluded. Specify a 10304 list of network blocks, hostnames or .domain names (the initial 10305 dot causes the domain to match any name below it). 10306 </p> 10307 10308 <p> Note: IP version 6 address information must be specified inside 10309 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a> value, and 10310 in files specified with "/file/name". IP version 6 addresses 10311 contain the ":" character, and would otherwise be confused with a 10312 "<a href="DATABASE_README.html">type:table</a>" pattern. </p> 10313 10314 <p> 10315 This feature is available in Postfix 2.2 and later. 10316 </p> 10317 10318 10319 </DD> 10320 10321 <DT><b><a name="smtpd_client_message_rate_limit">smtpd_client_message_rate_limit</a> 10322 (default: 0)</b></DT><DD> 10323 10324 <p> 10325 The maximal number of message delivery requests that any client is 10326 allowed to make to this service per time unit, regardless of whether 10327 or not Postfix actually accepts those messages. The time unit is 10328 specified with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter. 10329 </p> 10330 10331 <p> 10332 By default, a client can send as many message delivery requests 10333 per time unit as Postfix can accept. 10334 </p> 10335 10336 <p> 10337 To disable this feature, specify a limit of 0. 10338 </p> 10339 10340 <p> 10341 WARNING: The purpose of this feature is to limit abuse. It must 10342 not be used to regulate legitimate mail traffic. 10343 </p> 10344 10345 <p> 10346 This feature is available in Postfix 2.2 and later. 10347 </p> 10348 10349 <p> 10350 Example: 10351 </p> 10352 10353 <pre> 10354 <a href="postconf.5.html#smtpd_client_message_rate_limit">smtpd_client_message_rate_limit</a> = 1000 10355 </pre> 10356 10357 10358 </DD> 10359 10360 <DT><b><a name="smtpd_client_new_tls_session_rate_limit">smtpd_client_new_tls_session_rate_limit</a> 10361 (default: 0)</b></DT><DD> 10362 10363 <p> 10364 The maximal number of new (i.e., uncached) TLS sessions that a 10365 remote SMTP client is allowed to negotiate with this service per 10366 time unit. The time unit is specified with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> 10367 configuration parameter. 10368 </p> 10369 10370 <p> 10371 By default, a remote SMTP client can negotiate as many new TLS 10372 sessions per time unit as Postfix can accept. 10373 </p> 10374 10375 <p> 10376 To disable this feature, specify a limit of 0. Otherwise, specify 10377 a limit that is at least the per-client concurrent session limit, 10378 or else legitimate client sessions may be rejected. 10379 </p> 10380 10381 <p> 10382 WARNING: The purpose of this feature is to limit abuse. It must 10383 not be used to regulate legitimate mail traffic. 10384 </p> 10385 10386 <p> 10387 This feature is available in Postfix 2.3 and later. 10388 </p> 10389 10390 <p> 10391 Example: 10392 </p> 10393 10394 <pre> 10395 <a href="postconf.5.html#smtpd_client_new_tls_session_rate_limit">smtpd_client_new_tls_session_rate_limit</a> = 100 10396 </pre> 10397 10398 10399 </DD> 10400 10401 <DT><b><a name="smtpd_client_port_logging">smtpd_client_port_logging</a> 10402 (default: no)</b></DT><DD> 10403 10404 <p> Enable logging of the remote SMTP client port in addition to 10405 the hostname and IP address. The logging format is "host[address]:port". 10406 </p> 10407 10408 <p> This feature is available in Postfix 2.5 and later. </p> 10409 10410 10411 </DD> 10412 10413 <DT><b><a name="smtpd_client_recipient_rate_limit">smtpd_client_recipient_rate_limit</a> 10414 (default: 0)</b></DT><DD> 10415 10416 <p> 10417 The maximal number of recipient addresses that any client is allowed 10418 to send to this service per time unit, regardless of whether or not 10419 Postfix actually accepts those recipients. The time unit is specified 10420 with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter. 10421 </p> 10422 10423 <p> 10424 By default, a client can make as many recipient addresses per time 10425 unit as Postfix can accept. 10426 </p> 10427 10428 <p> 10429 To disable this feature, specify a limit of 0. 10430 </p> 10431 10432 <p> 10433 WARNING: The purpose of this feature is to limit abuse. It must 10434 not be used to regulate legitimate mail traffic. 10435 </p> 10436 10437 <p> 10438 This feature is available in Postfix 2.2 and later. 10439 </p> 10440 10441 <p> 10442 Example: 10443 </p> 10444 10445 <pre> 10446 <a href="postconf.5.html#smtpd_client_recipient_rate_limit">smtpd_client_recipient_rate_limit</a> = 1000 10447 </pre> 10448 10449 10450 </DD> 10451 10452 <DT><b><a name="smtpd_client_restrictions">smtpd_client_restrictions</a> 10453 (default: empty)</b></DT><DD> 10454 10455 <p> 10456 Optional SMTP server access restrictions in the context of a client 10457 SMTP connection request. 10458 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 10459 restriction lists" for a discussion of evaluation context and time. 10460 </p> 10461 10462 <p> 10463 The default is to allow all connection requests. 10464 </p> 10465 10466 <p> 10467 Specify a list of restrictions, separated by commas and/or whitespace. 10468 Continue long lines by starting the next line with whitespace. 10469 Restrictions are applied in the order as specified; the first 10470 restriction that matches wins. 10471 </p> 10472 10473 <p> 10474 The following restrictions are specific to client hostname or 10475 client network address information. 10476 </p> 10477 10478 <dl> 10479 10480 <dt><b><a name="check_ccert_access">check_ccert_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 10481 10482 <dd> Use the client certificate fingerprint as lookup key for the 10483 specified <a href="access.5.html">access(5)</a> database; with Postfix version 2.2, also require that 10484 the SMTP client certificate is verified successfully. 10485 The fingerprint digest algorithm is configurable via the 10486 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to 10487 Postfix version 2.5). This feature is available with Postfix version 10488 2.2 and later. </dd> 10489 10490 <dt><b><a name="check_client_access">check_client_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 10491 10492 <dd>Search the specified access database for the client hostname, 10493 parent domains, client IP address, or networks obtained by stripping 10494 least significant octets. See the <a href="access.5.html">access(5)</a> manual page for details. </dd> 10495 10496 <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> 10497 10498 <dd>Search the specified access database for the unverified reverse 10499 client hostname, parent domains, client IP address, or networks 10500 obtained by stripping least significant octets. See the <a href="access.5.html">access(5)</a> 10501 manual page for details. Note: a result of "OK" is not allowed for 10502 safety reasons. Instead, use DUNNO in order to exclude specific 10503 hosts from blacklists. This feature is available in Postfix 2.6 10504 and later.</dd> 10505 10506 <dt><b><a name="permit_inet_interfaces">permit_inet_interfaces</a></b></dt> 10507 10508 <dd>Permit the request when the client IP address matches 10509 $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>. </dd> 10510 10511 <dt><b><a name="permit_mynetworks">permit_mynetworks</a></b></dt> 10512 10513 <dd>Permit the request when the client IP address matches any 10514 network or network address listed in $<a href="postconf.5.html#mynetworks">mynetworks</a>. </dd> 10515 10516 <dt><b><a name="permit_sasl_authenticated">permit_sasl_authenticated</a></b></dt> 10517 10518 <dd> Permit the request when the client is successfully 10519 authenticated via the <a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a> (AUTH) protocol. </dd> 10520 10521 <dt><b><a name="permit_tls_all_clientcerts">permit_tls_all_clientcerts</a></b></dt> 10522 10523 <dd> Permit the request when the remote SMTP client certificate is 10524 verified successfully. This option must be used only if a special 10525 CA issues the certificates and only this CA is listed as trusted 10526 CA, otherwise all clients with a recognized certificate would be 10527 allowed to relay. This feature is available with Postfix version 2.2.</dd> 10528 10529 <dt><b><a name="permit_tls_clientcerts">permit_tls_clientcerts</a></b></dt> 10530 10531 <dd>Permit the request when the remote SMTP client certificate 10532 fingerprint is listed in $<a href="postconf.5.html#relay_clientcerts">relay_clientcerts</a>. 10533 The fingerprint digest algorithm is configurable via the 10534 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to 10535 Postfix version 2.5). This feature is available with Postfix version 10536 2.2. </dd> 10537 10538 <dt><b><a name="reject_rbl_client">reject_rbl_client <i>rbl_domain=d.d.d.d</i></a></b></dt> 10539 10540 <dd>Reject the request when the reversed client network address is 10541 listed with the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> 10542 (Postfix version 2.1 and later only). If no "<i>=d.d.d.d</i>" is 10543 specified, reject the request when the reversed client network 10544 address is listed with any A record under <i>rbl_domain</i>. <br> 10545 The <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> parameter specifies the response code for 10546 rejected requests (default: 554), the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> parameter 10547 specifies the default server reply, and the <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> parameter 10548 specifies tables with server replies indexed by <i>rbl_domain</i>. 10549 This feature is available in Postfix 2.0 and later. </dd> 10550 10551 <dt><b><a name="reject_rhsbl_client">reject_rhsbl_client <i>rbl_domain=d.d.d.d</i></a></b></dt> 10552 10553 <dd>Reject the request when the client hostname is listed with the 10554 A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> (Postfix version 10555 2.1 and later only). If no "<i>=d.d.d.d</i>" is specified, reject 10556 the request when the client hostname is listed with 10557 any A record under <i>rbl_domain</i>. See the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> 10558 description above for additional RBL related configuration parameters. 10559 This feature is available in Postfix 2.0 and later. </dd> 10560 10561 <dt><b><a name="reject_unknown_client_hostname">reject_unknown_client_hostname</a></b> (with Postfix < 2.3: reject_unknown_client)</dt> 10562 10563 <dd>Reject the request when 1) the client IP address->name mapping 10564 fails, 2) the name->address mapping fails, or 3) the name->address 10565 mapping does not match the client IP address. <br> This is a 10566 stronger restriction than the <a href="postconf.5.html#reject_unknown_reverse_client_hostname">reject_unknown_reverse_client_hostname</a> 10567 feature, which triggers only under condition 1) above. <br> The 10568 <a href="postconf.5.html#unknown_client_reject_code">unknown_client_reject_code</a> parameter specifies the response code 10569 for rejected requests (default: 450). The reply is always 450 in 10570 case the address->name or name->address lookup failed due to 10571 a temporary problem. </dd> 10572 10573 <dt><b><a name="reject_unknown_reverse_client_hostname">reject_unknown_reverse_client_hostname</a></b></dt> 10574 10575 <dd>Reject the request when the client IP address has no address->name 10576 mapping. <br> This is a weaker restriction than the 10577 <a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> feature, which requires not only 10578 that the address->name and name->address mappings exist, but 10579 also that the two mappings reproduce the client IP address. <br> 10580 The <a href="postconf.5.html#unknown_client_reject_code">unknown_client_reject_code</a> parameter specifies the response 10581 code for rejected requests (default: 450). The reply is always 450 10582 in case the address->name lookup failed due to a temporary 10583 problem. <br> This feature is available in Postfix 2.3 and 10584 later. </dd> 10585 10586 </dl> 10587 10588 <p> 10589 In addition, you can use any of the following <a name="generic"> 10590 generic</a> restrictions. These restrictions are applicable in 10591 any SMTP command context. 10592 </p> 10593 10594 <dl> 10595 10596 <dt><b><a name="check_policy_service">check_policy_service <i>servername</i></a></b></dt> 10597 10598 <dd>Query the specified policy server. See the <a href="SMTPD_POLICY_README.html">SMTPD_POLICY_README</a> 10599 document for details. This feature is available in Postfix 2.1 10600 and later. </dd> 10601 10602 <dt><b><a name="defer">defer</a></b></dt> 10603 10604 <dd>Defer the request. The client is told to try again later. This 10605 restriction is useful at the end of a restriction list, to make 10606 the default policy explicit. <br> The <a href="postconf.5.html#defer_code">defer_code</a> parameter specifies 10607 the SMTP server reply code (default: 450).</dd> 10608 10609 <dt><b><a name="defer_if_permit">defer_if_permit</a></b></dt> 10610 10611 <dd>Defer the request if some later restriction would result in an 10612 explicit or implicit PERMIT action. This is useful when a blacklisting 10613 feature fails due to a temporary problem. This feature is available 10614 in Postfix version 2.1 and later. </dd> 10615 10616 <dt><b><a name="defer_if_reject">defer_if_reject</a></b></dt> 10617 10618 <dd>Defer the request if some later restriction would result in a 10619 REJECT action. This is useful when a whitelisting feature fails 10620 due to a temporary problem. This feature is available in Postfix 10621 version 2.1 and later. </dd> 10622 10623 <dt><b><a name="permit">permit</a></b></dt> 10624 10625 <dd>Permit the request. This restriction is useful at the end of 10626 a restriction list, to make the default policy explicit.</dd> 10627 10628 <dt><b><a name="reject_multi_recipient_bounce">reject_multi_recipient_bounce</a></b></dt> 10629 10630 <dd>Reject the request when the envelope sender is the null address, 10631 and the message has multiple envelope recipients. This usage has 10632 rare but legitimate applications: under certain conditions, 10633 multi-recipient mail that was posted with the DSN option NOTIFY=NEVER 10634 may be forwarded with the null sender address. 10635 <br> Note: this restriction can only work reliably 10636 when used in <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> or 10637 <a href="postconf.5.html#smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a>, because the total number of 10638 recipients is not known at an earlier stage of the SMTP conversation. 10639 Use at the RCPT stage will only reject the second etc. recipient. 10640 <br> 10641 The <a href="postconf.5.html#multi_recipient_bounce_reject_code">multi_recipient_bounce_reject_code</a> parameter specifies the 10642 response code for rejected requests (default: 550). This feature 10643 is available in Postfix 2.1 and later. </dd> 10644 10645 <dt><b><a name="reject_plaintext_session">reject_plaintext_session</a></b></dt> 10646 10647 <dd>Reject the request when the connection is not encrypted. This 10648 restriction should not be used before the client has had a chance 10649 to negotiate encryption with the AUTH or STARTTLS commands. 10650 <br> 10651 The <a href="postconf.5.html#plaintext_reject_code">plaintext_reject_code</a> parameter specifies the response 10652 code for rejected requests (default: 450). This feature is available 10653 in Postfix 2.3 and later. </dd> 10654 10655 <dt><b><a name="reject_unauth_pipelining">reject_unauth_pipelining</a></b></dt> 10656 10657 <dd>Reject the request when the client sends SMTP commands ahead 10658 of time where it is not allowed, or when the client sends SMTP 10659 commands ahead of time without knowing that Postfix actually supports 10660 ESMTP command pipelining. This stops mail from bulk mail software 10661 that improperly uses ESMTP command pipelining in order to speed up 10662 deliveries. 10663 <br> With Postfix 2.6 and later, the SMTP server sets a per-session 10664 flag whenever it detects illegal pipelining, including pipelined 10665 EHLO or HELO commands. The <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> feature simply 10666 tests whether the flag was set at any point in time during the 10667 session. 10668 <br> With older Postfix versions, <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> checks 10669 the current status of the input read queue, and its usage is not 10670 recommended in contexts other than <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a>. </dd> 10671 10672 <dt><b><a name="reject">reject</a></b></dt> 10673 10674 <dd>Reject the request. This restriction is useful at the end of 10675 a restriction list, to make the default policy explicit. The 10676 <a href="postconf.5.html#reject_code">reject_code</a> configuration parameter specifies the response code for 10677 rejected requests (default: 554).</dd> 10678 10679 <dt><b><a name="sleep">sleep <i>seconds</i></a></b></dt> 10680 10681 <dd>Pause for the specified number of seconds and proceed with 10682 the next restriction in the list, if any. This may stop zombie 10683 mail when used as: 10684 <pre> 10685 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 10686 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> = 10687 sleep 1, <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> 10688 <a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = no 10689 </pre> 10690 This feature is available in Postfix 2.3. </dd> 10691 10692 <dt><b><a name="warn_if_reject">warn_if_reject</a></b></dt> 10693 10694 <dd>Change the meaning of the next restriction, so that it logs 10695 a warning instead of rejecting a request (look for logfile records 10696 that contain "reject_warning"). This is useful for testing new 10697 restrictions in a "live" environment without risking unnecessary 10698 loss of mail. </dd> 10699 10700 </dl> 10701 10702 <p> 10703 Other restrictions that are valid in this context: 10704 </p> 10705 10706 <ul> 10707 10708 <li> SMTP command specific restrictions that are described under 10709 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 10710 <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> parameters. When helo, sender or 10711 recipient restrictions are listed under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, 10712 they have effect only with "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes", so that 10713 $<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> is evaluated at the time of the RCPT TO 10714 command. 10715 10716 </ul> 10717 10718 <p> 10719 Example: 10720 </p> 10721 10722 <pre> 10723 <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> 10724 </pre> 10725 10726 10727 </DD> 10728 10729 <DT><b><a name="smtpd_data_restrictions">smtpd_data_restrictions</a> 10730 (default: empty)</b></DT><DD> 10731 10732 <p> 10733 Optional access restrictions that the Postfix SMTP server applies 10734 in the context of the SMTP DATA command. 10735 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 10736 restriction lists" for a discussion of evaluation context and time. 10737 </p> 10738 10739 <p> 10740 This feature is available in Postfix 2.0 and later. 10741 </p> 10742 10743 <p> 10744 Specify a list of restrictions, separated by commas and/or whitespace. 10745 Continue long lines by starting the next line with whitespace. 10746 Restrictions are applied in the order as specified; the first 10747 restriction that matches wins. 10748 </p> 10749 10750 <p> 10751 The following restrictions are valid in this context: 10752 </p> 10753 10754 <ul> 10755 10756 <li><a href="#generic">Generic</a> restrictions that can be used 10757 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 10758 10759 <li>SMTP command specific restrictions described under 10760 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>, 10761 <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>. 10762 10763 </ul> 10764 10765 <p> 10766 Examples: 10767 </p> 10768 10769 <pre> 10770 <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> = <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> 10771 <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> 10772 </pre> 10773 10774 10775 </DD> 10776 10777 <DT><b><a name="smtpd_delay_open_until_valid_rcpt">smtpd_delay_open_until_valid_rcpt</a> 10778 (default: yes)</b></DT><DD> 10779 10780 <p> Postpone the start of an SMTP mail transaction until a valid 10781 RCPT TO command is received. Specify "no" to create a mail transaction 10782 as soon as the SMTP server receives a valid MAIL FROM command. </p> 10783 10784 <p> With sites that reject lots of mail, the default setting reduces 10785 the use of 10786 disk, CPU and memory resources. The downside is that rejected 10787 recipients are logged with NOQUEUE instead of a mail transaction 10788 ID. This complicates the logfile analysis of multi-recipient mail. 10789 </p> 10790 10791 <p> This feature is available in Postfix 2.3 and later. </p> 10792 10793 10794 </DD> 10795 10796 <DT><b><a name="smtpd_delay_reject">smtpd_delay_reject</a> 10797 (default: yes)</b></DT><DD> 10798 10799 <p> 10800 Wait until the RCPT TO command before evaluating 10801 $<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 10802 $<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>, or wait until the ETRN command before 10803 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>. 10804 </p> 10805 10806 <p> 10807 This feature is turned on by default because some clients apparently 10808 mis-behave when the Postfix SMTP server rejects commands before 10809 RCPT TO. 10810 </p> 10811 10812 <p> 10813 The default setting has one major benefit: it allows Postfix to log 10814 recipient address information when rejecting a client name/address 10815 or sender address, so that it is possible to find out whose mail 10816 is being rejected. 10817 </p> 10818 10819 10820 </DD> 10821 10822 <DT><b><a name="smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a> 10823 (default: empty)</b></DT><DD> 10824 10825 <p> Lookup tables, indexed by the remote SMTP client address, with 10826 case insensitive lists of EHLO keywords (pipelining, starttls, auth, 10827 etc.) that the SMTP server will not send in the EHLO response to a 10828 remote SMTP client. See <a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a> for details. 10829 The table is not searched by hostname for robustness reasons. </p> 10830 10831 <p> This feature is available in Postfix 2.2 and later. </p> 10832 10833 10834 </DD> 10835 10836 <DT><b><a name="smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a> 10837 (default: empty)</b></DT><DD> 10838 10839 <p> A case insensitive list of EHLO keywords (pipelining, starttls, 10840 auth, etc.) that the SMTP server will not send in the EHLO response 10841 to a remote SMTP client. </p> 10842 10843 <p> This feature is available in Postfix 2.2 and later. </p> 10844 10845 <p> Notes: </p> 10846 10847 <ul> 10848 10849 <li> <p> Specify the <b>silent-discard</b> pseudo keyword to prevent 10850 this action from being logged. </p> 10851 10852 <li> <p> Use the <a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a> feature 10853 to discard EHLO keywords selectively. </p> 10854 10855 </ul> 10856 10857 10858 </DD> 10859 10860 <DT><b><a name="smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a> 10861 (default: empty)</b></DT><DD> 10862 10863 <p> Optional access restrictions that the Postfix SMTP server 10864 applies in the context of the SMTP END-OF-DATA command. 10865 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 10866 restriction lists" for a discussion of evaluation context and time. 10867 </p> 10868 10869 <p> This feature is available in Postfix 2.2 and later. </p> 10870 10871 <p> See <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> for syntax details. </p> 10872 10873 10874 </DD> 10875 10876 <DT><b><a name="smtpd_enforce_tls">smtpd_enforce_tls</a> 10877 (default: no)</b></DT><DD> 10878 10879 <p> Mandatory TLS: announce STARTTLS support to SMTP clients, 10880 and require that clients use TLS encryption. According to <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> 10881 this MUST NOT be applied in case of a publicly-referenced SMTP 10882 server. This option is off by default and should be used only on 10883 dedicated servers. </p> 10884 10885 <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> 10886 10887 <p> Note 2: when invoked via "<b>sendmail -bs</b>", Postfix will never offer 10888 STARTTLS due to insufficient privileges to access the server private 10889 key. This is intended behavior. </p> 10890 10891 <p> This feature is available in Postfix 2.2 and later. With 10892 Postfix 2.3 and later use <a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> instead. </p> 10893 10894 10895 </DD> 10896 10897 <DT><b><a name="smtpd_error_sleep_time">smtpd_error_sleep_time</a> 10898 (default: 1s)</b></DT><DD> 10899 10900 <p>With Postfix version 2.1 and later: the SMTP server response delay after 10901 a client has made more than $<a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> errors, and 10902 fewer than $<a href="postconf.5.html#smtpd_hard_error_limit">smtpd_hard_error_limit</a> errors, without delivering mail. 10903 </p> 10904 10905 <p>With Postfix version 2.0 and earlier: the SMTP server delay before 10906 sending a reject (4xx or 5xx) response, when the client has made 10907 fewer than $<a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> errors without delivering 10908 mail. </p> 10909 10910 10911 </DD> 10912 10913 <DT><b><a name="smtpd_etrn_restrictions">smtpd_etrn_restrictions</a> 10914 (default: empty)</b></DT><DD> 10915 10916 <p> 10917 Optional SMTP server access restrictions in the context of a client 10918 ETRN request. 10919 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 10920 restriction lists" for a discussion of evaluation context and time. 10921 </p> 10922 10923 <p> 10924 The Postfix ETRN implementation accepts only destinations that are 10925 eligible for the Postfix "fast flush" service. See the <a href="ETRN_README.html">ETRN_README</a> 10926 file for details. 10927 </p> 10928 10929 <p> 10930 Specify a list of restrictions, separated by commas and/or whitespace. 10931 Continue long lines by starting the next line with whitespace. 10932 Restrictions are applied in the order as specified; the first 10933 restriction that matches wins. 10934 </p> 10935 10936 <p> 10937 The following restrictions are specific to the domain name information 10938 received with the ETRN command. 10939 </p> 10940 10941 <dl> 10942 10943 <dt><b><a name="check_etrn_access">check_etrn_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 10944 10945 <dd>Search the specified access database for the ETRN domain name 10946 or its parent domains. See the <a href="access.5.html">access(5)</a> manual page for details. 10947 </dd> 10948 10949 </dl> 10950 10951 <p> 10952 Other restrictions that are valid in this context: 10953 </p> 10954 10955 <ul> 10956 10957 <li><a href="#generic">Generic</a> restrictions that can be used 10958 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 10959 10960 <li>SMTP command specific restrictions described under 10961 <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>. 10962 10963 </ul> 10964 10965 <p> 10966 Example: 10967 </p> 10968 10969 <pre> 10970 <a href="postconf.5.html#smtpd_etrn_restrictions">smtpd_etrn_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, reject 10971 </pre> 10972 10973 10974 </DD> 10975 10976 <DT><b><a name="smtpd_expansion_filter">smtpd_expansion_filter</a> 10977 (default: see "postconf -d" output)</b></DT><DD> 10978 10979 <p> 10980 What characters are allowed in $name expansions of RBL reply 10981 templates. Characters not in the allowed set are replaced by "_". 10982 Use C like escapes to specify special characters such as whitespace. 10983 </p> 10984 10985 <p> 10986 This parameter is not subjected to $parameter expansion. 10987 </p> 10988 10989 <p> 10990 This feature is available in Postfix 2.0 and later. 10991 </p> 10992 10993 10994 </DD> 10995 10996 <DT><b><a name="smtpd_forbidden_commands">smtpd_forbidden_commands</a> 10997 (default: CONNECT, GET, POST)</b></DT><DD> 10998 10999 <p> 11000 List of commands that causes the Postfix SMTP server to immediately 11001 terminate the session with a 221 code. This can be used to disconnect 11002 clients that obviously attempt to abuse the system. In addition to the 11003 commands listed in this parameter, commands that follow the "Label:" 11004 format of message headers will also cause a disconnect. 11005 </p> 11006 11007 <p> 11008 This feature is available in Postfix 2.2 and later. 11009 </p> 11010 11011 11012 </DD> 11013 11014 <DT><b><a name="smtpd_hard_error_limit">smtpd_hard_error_limit</a> 11015 (default: normal: 20, stress: 1)</b></DT><DD> 11016 11017 <p> 11018 The maximal number of errors a remote SMTP client is allowed to 11019 make without delivering mail. The Postfix SMTP server disconnects 11020 when the limit is exceeded. Normally the default limit is 20, but 11021 it changes under overload to just 1 with Postfix 2.6 and later. 11022 </p> 11023 11024 11025 </DD> 11026 11027 <DT><b><a name="smtpd_helo_required">smtpd_helo_required</a> 11028 (default: no)</b></DT><DD> 11029 11030 <p> 11031 Require that a remote SMTP client introduces itself at the beginning 11032 of an SMTP session with the HELO or EHLO command. 11033 </p> 11034 11035 <p> 11036 Example: 11037 </p> 11038 11039 <pre> 11040 <a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes 11041 </pre> 11042 11043 11044 </DD> 11045 11046 <DT><b><a name="smtpd_helo_restrictions">smtpd_helo_restrictions</a> 11047 (default: empty)</b></DT><DD> 11048 11049 <p> 11050 Optional restrictions that the Postfix SMTP server applies in the 11051 context of the SMTP HELO command. 11052 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 11053 restriction lists" for a discussion of evaluation context and time. 11054 </p> 11055 11056 <p> 11057 The default is to permit everything. 11058 </p> 11059 11060 <p> 11061 Specify a list of restrictions, separated by commas and/or whitespace. 11062 Continue long lines by starting the next line with whitespace. 11063 Restrictions are applied in the order as specified; the first 11064 restriction that matches wins. 11065 </p> 11066 11067 <p> 11068 The following restrictions are specific to the hostname information 11069 received with the HELO or EHLO command. 11070 </p> 11071 11072 <dl> 11073 11074 <dt><b><a name="check_helo_access">check_helo_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11075 11076 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the HELO or EHLO 11077 hostname or parent domains, and execute the corresponding action. 11078 </dd> 11079 11080 <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> 11081 11082 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for 11083 the HELO or EHLO hostname, and execute the corresponding action. 11084 Note: a result of "OK" is not allowed for safety reasons. Instead, 11085 use DUNNO in order to exclude specific hosts from blacklists. This 11086 feature is available in Postfix 2.1 and later. </dd> 11087 11088 <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> 11089 11090 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers 11091 for the HELO or EHLO hostname, and execute the corresponding action. 11092 Note: a result of "OK" is not allowed for safety reasons. Instead, 11093 use DUNNO in order to exclude specific hosts from blacklists. This 11094 feature is available in Postfix 2.1 and later. </dd> 11095 11096 <dt><b><a name="reject_invalid_helo_hostname">reject_invalid_helo_hostname</a></b> (with Postfix < 2.3: reject_invalid_hostname)</dt> 11097 11098 <dd>Reject the request when the HELO or EHLO hostname syntax is 11099 invalid. <br> The <a href="postconf.5.html#invalid_hostname_reject_code">invalid_hostname_reject_code</a> specifies the response 11100 code for rejected requests (default: 501).</dd> 11101 11102 <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> 11103 11104 <dd>Reject the request when the HELO or EHLO hostname is not in 11105 fully-qualified domain form, as required by the RFC. <br> The 11106 <a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> parameter specifies the response code for 11107 rejected requests (default: 504).</dd> 11108 11109 <dt><b><a name="reject_rhsbl_helo">reject_rhsbl_helo <i>rbl_domain=d.d.d.d</i></a></b></dt> 11110 11111 <dd>Reject the request when the HELO or EHLO hostname hostname is 11112 listed with the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> 11113 (Postfix version 2.1 and later only). If no "<i>=d.d.d.d</i>" is 11114 specified, reject the request when the HELO or EHLO hostname is 11115 listed with any A record under <i>rbl_domain</i>. See the 11116 <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> description for additional RBL related configuration 11117 parameters. This feature is available in Postfix 2.0 and later. 11118 </dd> 11119 11120 <dt><b><a name="reject_unknown_helo_hostname">reject_unknown_helo_hostname</a></b> (with Postfix < 2.3: reject_unknown_hostname)</dt> 11121 11122 <dd>Reject the request when the HELO or EHLO hostname has no DNS A 11123 or MX record. <br> The <a href="postconf.5.html#unknown_hostname_reject_code">unknown_hostname_reject_code</a> parameter 11124 specifies the numerical response code for rejected requests (default: 11125 450). <br> The <a href="postconf.5.html#unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a> parameter 11126 specifies the action after a temporary DNS error (default: 11127 <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). </dd> 11128 11129 </dl> 11130 11131 <p> 11132 Other restrictions that are valid in this context: 11133 </p> 11134 11135 <ul> 11136 11137 <li> <a href="#generic">Generic</a> restrictions that can be used 11138 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 11139 11140 <li> Client hostname or network address specific restrictions 11141 described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 11142 11143 <li> SMTP command specific restrictions described under 11144 <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 11145 sender or recipient restrictions are listed under <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>, 11146 they have effect only with "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes", so that 11147 $<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> is evaluated at the time of the RCPT TO 11148 command. 11149 11150 </ul> 11151 11152 <p> 11153 Examples: 11154 </p> 11155 11156 <pre> 11157 <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> 11158 <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> 11159 </pre> 11160 11161 11162 </DD> 11163 11164 <DT><b><a name="smtpd_history_flush_threshold">smtpd_history_flush_threshold</a> 11165 (default: 100)</b></DT><DD> 11166 11167 <p> 11168 The maximal number of lines in the Postfix SMTP server command history 11169 before it is flushed upon receipt of EHLO, RSET, or end of DATA. 11170 </p> 11171 11172 11173 </DD> 11174 11175 <DT><b><a name="smtpd_junk_command_limit">smtpd_junk_command_limit</a> 11176 (default: normal: 100, stress: 1)</b></DT><DD> 11177 11178 <p> 11179 The number of junk commands (NOOP, VRFY, ETRN or RSET) that a remote 11180 SMTP client can send before the Postfix SMTP server starts to 11181 increment the error counter with each junk command. The junk 11182 command count is reset after mail is delivered. See also the 11183 <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 11184 parameters. Normally the default limit is 100, but it changes under 11185 overload to just 1 with Postfix 2.6 and later. 11186 </p> 11187 11188 11189 </DD> 11190 11191 <DT><b><a name="smtpd_milters">smtpd_milters</a> 11192 (default: empty)</b></DT><DD> 11193 11194 <p> A list of Milter (mail filter) applications for new mail that 11195 arrives via the Postfix <a href="smtpd.8.html">smtpd(8)</a> server. See the <a href="MILTER_README.html">MILTER_README</a> 11196 document for details. </p> 11197 11198 <p> This feature is available in Postfix 2.3 and later. </p> 11199 11200 11201 </DD> 11202 11203 <DT><b><a name="smtpd_noop_commands">smtpd_noop_commands</a> 11204 (default: empty)</b></DT><DD> 11205 11206 <p> 11207 List of commands that the Postfix SMTP server replies to with "250 11208 Ok", without doing any syntax checks and without changing state. 11209 This list overrides any commands built into the Postfix SMTP server. 11210 </p> 11211 11212 11213 </DD> 11214 11215 <DT><b><a name="smtpd_null_access_lookup_key">smtpd_null_access_lookup_key</a> 11216 (default: <>)</b></DT><DD> 11217 11218 <p> 11219 The lookup key to be used in SMTP <a href="access.5.html">access(5)</a> tables instead of the 11220 null sender address. 11221 </p> 11222 11223 11224 </DD> 11225 11226 <DT><b><a name="smtpd_peername_lookup">smtpd_peername_lookup</a> 11227 (default: yes)</b></DT><DD> 11228 11229 <p> Attempt to look up the remote SMTP client hostname, and verify that 11230 the name matches the client IP address. A client name is set to 11231 "unknown" when it cannot be looked up or verified, or when name 11232 lookup is disabled. Turning off name lookup reduces delays due to 11233 DNS lookup and increases the maximal inbound delivery rate. </p> 11234 11235 <p> This feature is available in Postfix 2.3 and later. </p> 11236 11237 11238 </DD> 11239 11240 <DT><b><a name="smtpd_policy_service_max_idle">smtpd_policy_service_max_idle</a> 11241 (default: 300s)</b></DT><DD> 11242 11243 <p> 11244 The time after which an idle SMTPD policy service connection is 11245 closed. 11246 </p> 11247 11248 <p> 11249 This feature is available in Postfix 2.1 and later. 11250 </p> 11251 11252 11253 </DD> 11254 11255 <DT><b><a name="smtpd_policy_service_max_ttl">smtpd_policy_service_max_ttl</a> 11256 (default: 1000s)</b></DT><DD> 11257 11258 <p> 11259 The time after which an active SMTPD policy service connection is 11260 closed. 11261 </p> 11262 11263 <p> 11264 This feature is available in Postfix 2.1 and later. 11265 </p> 11266 11267 11268 </DD> 11269 11270 <DT><b><a name="smtpd_policy_service_timeout">smtpd_policy_service_timeout</a> 11271 (default: 100s)</b></DT><DD> 11272 11273 <p> 11274 The time limit for connecting to, writing to or receiving from a 11275 delegated SMTPD policy server. 11276 </p> 11277 11278 <p> 11279 This feature is available in Postfix 2.1 and later. 11280 </p> 11281 11282 11283 </DD> 11284 11285 <DT><b><a name="smtpd_proxy_ehlo">smtpd_proxy_ehlo</a> 11286 (default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD> 11287 11288 <p> 11289 How the Postfix SMTP server announces itself to the proxy filter. 11290 By default, the Postfix hostname is used. 11291 </p> 11292 11293 <p> 11294 This feature is available in Postfix 2.1 and later. 11295 </p> 11296 11297 11298 </DD> 11299 11300 <DT><b><a name="smtpd_proxy_filter">smtpd_proxy_filter</a> 11301 (default: empty)</b></DT><DD> 11302 11303 <p> The hostname and TCP port of the mail filtering proxy server. 11304 The proxy receives all mail from the Postfix SMTP server, and is 11305 supposed to give the result to another Postfix SMTP server process. 11306 </p> 11307 11308 <p> Specify "host:port" or "inet:host:port" for a TCP endpoint, or 11309 "unix:pathname" for a UNIX-domain endpoint. The host can be specified 11310 as an IP address or as a symbolic name; no MX lookups are done. 11311 When no "host" or "host:" are specified, the local machine is 11312 assumed. Pathname interpretation is relative to the Postfix queue 11313 directory. </p> 11314 11315 <p> This feature is available in Postfix 2.1 and later. </p> 11316 11317 <p> The "inet:" and "unix:" prefixes are available in Postfix 2.3 11318 and later. </p> 11319 11320 11321 </DD> 11322 11323 <DT><b><a name="smtpd_proxy_timeout">smtpd_proxy_timeout</a> 11324 (default: 100s)</b></DT><DD> 11325 11326 <p> 11327 The time limit for connecting to a proxy filter and for sending or 11328 receiving information. When a connection fails the client gets a 11329 generic error message while more detailed information is logged to 11330 the maillog file. 11331 </p> 11332 11333 <p> 11334 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 11335 The default time unit is s (seconds). 11336 </p> 11337 11338 <p> 11339 This feature is available in Postfix 2.1 and later. 11340 </p> 11341 11342 11343 </DD> 11344 11345 <DT><b><a name="smtpd_recipient_limit">smtpd_recipient_limit</a> 11346 (default: 1000)</b></DT><DD> 11347 11348 <p> 11349 The maximal number of recipients that the Postfix SMTP server 11350 accepts per message delivery request. 11351 </p> 11352 11353 11354 </DD> 11355 11356 <DT><b><a name="smtpd_recipient_overshoot_limit">smtpd_recipient_overshoot_limit</a> 11357 (default: 1000)</b></DT><DD> 11358 11359 <p> The number of recipients that a remote SMTP client can send in 11360 excess of the limit specified with $<a href="postconf.5.html#smtpd_recipient_limit">smtpd_recipient_limit</a>, before 11361 the Postfix SMTP server increments the per-session error count 11362 for each excess recipient. </p> 11363 11364 11365 </DD> 11366 11367 <DT><b><a name="smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> 11368 (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> 11369 11370 <p> 11371 The access restrictions that the Postfix SMTP server applies in 11372 the context of the RCPT TO command. 11373 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 11374 restriction lists" for a discussion of evaluation context and time. 11375 </p> 11376 11377 <p> 11378 By default, the Postfix SMTP server accepts: 11379 </p> 11380 11381 <ul> 11382 11383 <li> Mail from clients whose IP address matches $<a href="postconf.5.html#mynetworks">mynetworks</a>, or: 11384 11385 <li> Mail to remote destinations that match $<a href="postconf.5.html#relay_domains">relay_domains</a>, except 11386 for addresses that contain sender-specified routing 11387 (user@elsewhere@domain), or: 11388 11389 <li> Mail to local destinations that match $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> 11390 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 11391 $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. 11392 11393 </ul> 11394 11395 <p> 11396 IMPORTANT: If you change this parameter setting, you must specify 11397 at least one of the following restrictions. Otherwise Postfix will 11398 refuse to receive mail: 11399 </p> 11400 11401 <blockquote> 11402 <pre> 11403 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> 11404 </pre> 11405 </blockquote> 11406 11407 <p> 11408 Specify a list of restrictions, separated by commas and/or whitespace. 11409 Continue long lines by starting the next line with whitespace. 11410 Restrictions are applied in the order as specified; the first 11411 restriction that matches wins. 11412 </p> 11413 11414 <p> 11415 The following restrictions are specific to the recipient address 11416 that is received with the RCPT TO command. 11417 </p> 11418 11419 <dl> 11420 11421 <dt><b><a name="check_recipient_access">check_recipient_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11422 11423 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the resolved RCPT 11424 TO address, domain, parent domains, or localpart@, and execute the 11425 corresponding action. </dd> 11426 11427 <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> 11428 11429 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for 11430 the RCPT TO domain, and execute the corresponding action. Note: 11431 a result of "OK" is not allowed for safety reasons. Instead, use 11432 DUNNO in order to exclude specific hosts from blacklists. This 11433 feature is available in Postfix 2.1 and later. </dd> 11434 11435 <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> 11436 11437 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers 11438 for the RCPT TO domain, and execute the corresponding action. 11439 Note: a result of "OK" is not allowed for safety reasons. Instead, 11440 use DUNNO in order to exclude specific hosts from blacklists. This 11441 feature is available in Postfix 2.1 and later. </dd> 11442 11443 <dt><b><a name="permit_auth_destination">permit_auth_destination</a></b></dt> 11444 11445 <dd>Permit the request when one of the following is true: 11446 11447 <ul> 11448 11449 <li> Postfix is mail forwarder: the resolved RCPT TO domain matches 11450 $<a href="postconf.5.html#relay_domains">relay_domains</a> or a subdomain thereof, and the address contains no 11451 sender-specified routing (user@elsewhere@domain), 11452 11453 <li> Postfix is the final destination: the resolved RCPT TO domain 11454 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>, 11455 $<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 11456 contains no sender-specified routing (user@elsewhere@domain). 11457 11458 </ul></dd> 11459 11460 <dt><b><a name="permit_mx_backup">permit_mx_backup</a></b></dt> 11461 11462 <dd>Permit the request when the local mail system is backup MX for 11463 the RCPT TO domain, or when the domain is an authorized destination 11464 (see <a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a> for definition). 11465 11466 <ul> 11467 11468 <li> Safety: <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> does not accept addresses that have 11469 sender-specified routing information (example: user@elsewhere@domain). 11470 11471 <li> Safety: <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> can be vulnerable to mis-use when 11472 access is not restricted with <a href="postconf.5.html#permit_mx_backup_networks">permit_mx_backup_networks</a>. 11473 11474 <li> Safety: as of Postfix version 2.3, <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> no longer 11475 accepts the address when the local mail system is primary MX for 11476 the recipient domain. Exception: <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> accepts the address 11477 when it specifies an authorized destination (see <a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a> 11478 for definition). 11479 11480 <li> Limitation: mail may be rejected in case of a temporary DNS 11481 lookup problem with Postfix prior to version 2.0. 11482 11483 </ul></dd> 11484 11485 <dt><b><a name="reject_non_fqdn_recipient">reject_non_fqdn_recipient</a></b></dt> 11486 11487 <dd>Reject the request when the RCPT TO address is not in 11488 fully-qualified domain form, as required by the RFC. <br> The 11489 <a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> parameter specifies the response code for 11490 rejected requests (default: 504). </dd> 11491 11492 <dt><b><a name="reject_rhsbl_recipient">reject_rhsbl_recipient <i>rbl_domain=d.d.d.d</i></a></b></dt> 11493 11494 <dd>Reject the request when the RCPT TO domain is listed with the 11495 A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> (Postfix version 11496 2.1 and later only). If no "<i>=d.d.d.d</i>" is specified, reject 11497 the request when the RCPT TO domain is listed with 11498 any A record under <i>rbl_domain</i>. <br> The <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> 11499 parameter specifies the response code for rejected requests (default: 11500 554); the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> parameter specifies the default server 11501 reply; and the <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> parameter specifies tables with server 11502 replies indexed by <i>rbl_domain</i>. This feature is available 11503 in Postfix version 2.0 and later.</dd> 11504 11505 <dt><b><a name="reject_unauth_destination">reject_unauth_destination</a></b></dt> 11506 11507 <dd>Reject the request unless one of the following is true: 11508 11509 <ul> 11510 11511 <li> Postfix is mail forwarder: the resolved RCPT TO domain matches 11512 $<a href="postconf.5.html#relay_domains">relay_domains</a> or a subdomain thereof, and contains no sender-specified 11513 routing (user@elsewhere@domain), 11514 11515 <li> Postfix is the final destination: the resolved RCPT TO domain 11516 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>, 11517 $<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 11518 no sender-specified routing (user@elsewhere@domain). 11519 11520 </ul> The <a href="postconf.5.html#relay_domains_reject_code">relay_domains_reject_code</a> parameter specifies the response 11521 code for rejected requests (default: 554). </dd> 11522 11523 <dt><b><a name="reject_unknown_recipient_domain">reject_unknown_recipient_domain</a></b></dt> 11524 11525 <dd>Reject the request when Postfix is not final destination for 11526 the recipient domain, and the RCPT TO domain has no DNS A or MX 11527 record, or when it has a malformed MX record such as a record with 11528 a zero-length MX hostname (Postfix version 2.3 and later). <br> The 11529 <a href="postconf.5.html#unknown_address_reject_code">unknown_address_reject_code</a> parameter specifies the numerical 11530 response code for rejected requests (default: 450). The response 11531 is always 450 in case of a temporary DNS error. <br> The 11532 <a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a> parameter specifies the action 11533 after a temporary DNS error (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). </dd> 11534 11535 <dt><b><a name="reject_unlisted_recipient">reject_unlisted_recipient</a></b> (with Postfix version 2.0: check_recipient_maps)</dt> 11536 11537 <dd> Reject the request when the RCPT TO address is not listed in 11538 the list of valid recipients for its domain class. See the 11539 <a href="postconf.5.html#smtpd_reject_unlisted_recipient">smtpd_reject_unlisted_recipient</a> parameter description for details. 11540 This feature is available in Postfix 2.1 and later.</dd> 11541 11542 <dt><b><a name="reject_unverified_recipient">reject_unverified_recipient</a></b></dt> 11543 11544 <dd>Reject the request when mail to the RCPT TO address is known 11545 to bounce, or when the recipient address destination is not reachable. 11546 Address verification information is managed by the <a href="verify.8.html">verify(8)</a> server; 11547 see the <a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VERIFICATION_README</a> file for details. <br> The 11548 <a href="postconf.5.html#unverified_recipient_reject_code">unverified_recipient_reject_code</a> parameter specifies the numerical 11549 response code when an address is known to bounce (default: 450, 11550 change into 550 when you are confident that it is safe to do so). 11551 <br>The <a href="postconf.5.html#unverified_recipient_defer_code">unverified_recipient_defer_code</a> parameter specifies the 11552 numerical response code when an address probe failed due to a 11553 temporary problem (default: 450). <br> The 11554 <a href="postconf.5.html#unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a> parameter specifies the action 11555 after addres probe failure due to a temporary problem (default: 11556 <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). <br> This feature is available in Postfix 2.1 11557 and later. </dd> 11558 11559 </dl> 11560 11561 <p> 11562 Other restrictions that are valid in this context: 11563 </p> 11564 11565 <ul> 11566 11567 <li><a href="#generic">Generic</a> restrictions that can be used 11568 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 11569 11570 <li>SMTP command specific restrictions described under 11571 <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 11572 <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>. 11573 11574 </ul> 11575 11576 <p> 11577 Example: 11578 </p> 11579 11580 <pre> 11581 <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> 11582 </pre> 11583 11584 11585 </DD> 11586 11587 <DT><b><a name="smtpd_reject_unlisted_recipient">smtpd_reject_unlisted_recipient</a> 11588 (default: yes)</b></DT><DD> 11589 11590 <p> 11591 Request that the Postfix SMTP server rejects mail for unknown 11592 recipient addresses, even when no explicit <a href="postconf.5.html#reject_unlisted_recipient">reject_unlisted_recipient</a> 11593 access restriction is specified. This prevents the Postfix queue 11594 from filling up with undeliverable MAILER-DAEMON messages. 11595 </p> 11596 11597 <ul> 11598 11599 <li> The recipient domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> 11600 or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, but the recipient is not listed in 11601 $<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. 11602 11603 <li> The recipient domain matches $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> but the 11604 recipient is not listed in $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>. 11605 11606 <li> The recipient domain matches $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a> but the 11607 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> 11608 is not null. 11609 11610 <li> The recipient domain matches $<a href="postconf.5.html#relay_domains">relay_domains</a> but the recipient 11611 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> 11612 is not null. 11613 11614 </ul> 11615 11616 <p> 11617 This feature is available in Postfix 2.1 and later. 11618 </p> 11619 11620 11621 </DD> 11622 11623 <DT><b><a name="smtpd_reject_unlisted_sender">smtpd_reject_unlisted_sender</a> 11624 (default: no)</b></DT><DD> 11625 11626 <p> Request that the Postfix SMTP server rejects mail from unknown 11627 sender addresses, even when no explicit <a href="postconf.5.html#reject_unlisted_sender">reject_unlisted_sender</a> 11628 access restriction is specified. This can slow down an explosion 11629 of forged mail from worms or viruses. </p> 11630 11631 <ul> 11632 11633 <li> The sender domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or 11634 $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, but the sender is not listed in 11635 $<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. 11636 11637 <li> The sender domain matches $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> but the sender 11638 is not listed in $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>. 11639 11640 <li> The sender domain matches $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a> but the 11641 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> 11642 is not null. 11643 11644 <li> The sender domain matches $<a href="postconf.5.html#relay_domains">relay_domains</a> but the sender is 11645 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 11646 not null. 11647 11648 </ul> 11649 11650 <p> 11651 This feature is available in Postfix 2.1 and later. 11652 </p> 11653 11654 11655 </DD> 11656 11657 <DT><b><a name="smtpd_restriction_classes">smtpd_restriction_classes</a> 11658 (default: empty)</b></DT><DD> 11659 11660 <p> 11661 User-defined aliases for groups of access restrictions. The aliases 11662 can be specified in <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> etc., and on the 11663 right-hand side of a Postfix <a href="access.5.html">access(5)</a> table. 11664 </p> 11665 11666 <p> 11667 One major application is for implementing per-recipient UCE control. 11668 See the <a href="RESTRICTION_CLASS_README.html">RESTRICTION_CLASS_README</a> document for other examples. 11669 </p> 11670 11671 11672 </DD> 11673 11674 <DT><b><a name="smtpd_sasl_application_name">smtpd_sasl_application_name</a> 11675 (default: smtpd)</b></DT><DD> 11676 11677 <p> 11678 The application name that the Postfix SMTP server uses for SASL 11679 server initialization. This 11680 controls the name of the SASL configuration file. The default value 11681 is <b>smtpd</b>, corresponding to a SASL configuration file named 11682 <b>smtpd.conf</b>. 11683 </p> 11684 11685 <p> 11686 This feature is available in Postfix 2.1 and 2.2. With Postfix 2.3 11687 it was renamed to <a href="postconf.5.html#smtpd_sasl_path">smtpd_sasl_path</a>. 11688 </p> 11689 11690 11691 </DD> 11692 11693 <DT><b><a name="smtpd_sasl_auth_enable">smtpd_sasl_auth_enable</a> 11694 (default: no)</b></DT><DD> 11695 11696 <p> 11697 Enable SASL authentication in the Postfix SMTP server. By default, 11698 the Postfix SMTP server does not use authentication. 11699 </p> 11700 11701 <p> 11702 If a remote SMTP client is authenticated, the <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a> 11703 access restriction can be used to permit relay access, like this: 11704 </p> 11705 11706 <blockquote> 11707 <pre> 11708 <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> = 11709 <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a>, ... 11710 </pre> 11711 </blockquote> 11712 11713 <p> To reject all SMTP connections from unauthenticated clients, 11714 specify "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes" (which is the default) and use: 11715 </p> 11716 11717 <blockquote> 11718 <pre> 11719 <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 11720 </pre> 11721 </blockquote> 11722 11723 <p> 11724 See the <a href="SASL_README.html">SASL_README</a> file for SASL configuration and operation details. 11725 </p> 11726 11727 11728 </DD> 11729 11730 <DT><b><a name="smtpd_sasl_authenticated_header">smtpd_sasl_authenticated_header</a> 11731 (default: no)</b></DT><DD> 11732 11733 <p> Report the SASL authenticated user name in the <a href="smtpd.8.html">smtpd(8)</a> Received 11734 message header. </p> 11735 11736 <p> This feature is available in Postfix 2.3 and later. </p> 11737 11738 11739 </DD> 11740 11741 <DT><b><a name="smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> 11742 (default: empty)</b></DT><DD> 11743 11744 <p> 11745 What remote SMTP clients the Postfix SMTP server will not offer 11746 AUTH support to. 11747 </p> 11748 11749 <p> 11750 Some clients (Netscape 4 at least) have a bug that causes them to 11751 require a login and password whenever AUTH is offered, whether it's 11752 necessary or not. To work around this, specify, for example, 11753 $<a href="postconf.5.html#mynetworks">mynetworks</a> to prevent Postfix from offering AUTH to local clients. 11754 </p> 11755 11756 <p> 11757 Specify a list of network/netmask patterns, separated by commas 11758 and/or whitespace. The mask specifies the number of bits in the 11759 network part of a host address. You can also "/file/name" or 11760 "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" pattern is replaced by its 11761 contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a table entry 11762 matches a lookup string (the lookup result is ignored). Continue 11763 long lines by starting the next line with whitespace. Specify 11764 "!pattern" to exclude an address or network block from the list. 11765 The form "!/file/name" is supported only in Postfix version 2.4 and 11766 later. </p> 11767 11768 <p> Note: IP version 6 address information must be specified inside 11769 <tt>[]</tt> in the <a href="postconf.5.html#smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> value, and in 11770 files specified with "/file/name". IP version 6 addresses contain 11771 the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" 11772 pattern. </p> 11773 11774 <p> 11775 Example: 11776 </p> 11777 11778 <pre> 11779 <a href="postconf.5.html#smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> = $<a href="postconf.5.html#mynetworks">mynetworks</a> 11780 </pre> 11781 11782 <p> 11783 This feature is available in Postfix 2.1 and later. 11784 </p> 11785 11786 11787 </DD> 11788 11789 <DT><b><a name="smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> 11790 (default: empty)</b></DT><DD> 11791 11792 <p> 11793 The name of the Postfix SMTP server's local SASL authentication 11794 realm. 11795 </p> 11796 11797 <p> 11798 By default, the local authentication realm name is the null string. 11799 </p> 11800 11801 <p> 11802 Examples: 11803 </p> 11804 11805 <pre> 11806 <a href="postconf.5.html#smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> = $<a href="postconf.5.html#mydomain">mydomain</a> 11807 <a href="postconf.5.html#smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> = $<a href="postconf.5.html#myhostname">myhostname</a> 11808 </pre> 11809 11810 11811 </DD> 11812 11813 <DT><b><a name="smtpd_sasl_path">smtpd_sasl_path</a> 11814 (default: smtpd)</b></DT><DD> 11815 11816 <p> Implementation-specific information that the Postfix SMTP server 11817 passes through to 11818 the SASL plug-in implementation that is selected with 11819 <b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a></b>. Typically this specifies the name of a 11820 configuration file or rendezvous point. </p> 11821 11822 <p> This feature is available in Postfix 2.3 and later. In earlier 11823 releases it was called <b>smtpd_sasl_application_name</b>. </p> 11824 11825 11826 </DD> 11827 11828 <DT><b><a name="smtpd_sasl_security_options">smtpd_sasl_security_options</a> 11829 (default: noanonymous)</b></DT><DD> 11830 11831 <p> Postfix SMTP server SASL security options; as of Postfix 2.3 11832 the list of available 11833 features depends on the SASL server implementation that is selected 11834 with <b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a></b>. </p> 11835 11836 <p> The following security features are defined for the <b>cyrus</b> 11837 server SASL implementation: </p> 11838 11839 <p> 11840 Restrict what authentication mechanisms the Postfix SMTP server 11841 will offer to the client. The list of available authentication 11842 mechanisms is system dependent. 11843 </p> 11844 11845 <p> 11846 Specify zero or more of the following: 11847 </p> 11848 11849 <dl> 11850 11851 <dt><b>noplaintext</b></dt> 11852 11853 <dd>Disallow methods that use plaintext passwords. </dd> 11854 11855 <dt><b>noactive</b></dt> 11856 11857 <dd>Disallow methods subject to active (non-dictionary) attack. </dd> 11858 11859 <dt><b>nodictionary</b></dt> 11860 11861 <dd>Disallow methods subject to passive (dictionary) attack. </dd> 11862 11863 <dt><b>noanonymous</b></dt> 11864 11865 <dd>Disallow methods that allow anonymous authentication. </dd> 11866 11867 <dt><b>forward_secrecy</b></dt> 11868 11869 <dd>Only allow methods that support forward secrecy (Dovecot only). 11870 </dd> 11871 11872 <dt><b>mutual_auth</b></dt> 11873 11874 <dd>Only allow methods that provide mutual authentication (not available 11875 with Cyrus SASL version 1). </dd> 11876 11877 </dl> 11878 11879 <p> 11880 By default, the Postfix SMTP server accepts plaintext passwords but 11881 not anonymous logins. 11882 </p> 11883 11884 <p> 11885 Warning: it appears that clients try authentication methods in the 11886 order as advertised by the server (e.g., PLAIN ANONYMOUS CRAM-MD5) 11887 which means that if you disable plaintext passwords, clients will 11888 log in anonymously, even when they should be able to use CRAM-MD5. 11889 So, if you disable plaintext logins, disable anonymous logins too. 11890 Postfix treats anonymous login as no authentication. 11891 </p> 11892 11893 <p> 11894 Example: 11895 </p> 11896 11897 <pre> 11898 <a href="postconf.5.html#smtpd_sasl_security_options">smtpd_sasl_security_options</a> = noanonymous, noplaintext 11899 </pre> 11900 11901 11902 </DD> 11903 11904 <DT><b><a name="smtpd_sasl_tls_security_options">smtpd_sasl_tls_security_options</a> 11905 (default: $<a href="postconf.5.html#smtpd_sasl_security_options">smtpd_sasl_security_options</a>)</b></DT><DD> 11906 11907 <p> The SASL authentication security options that the Postfix SMTP 11908 server uses for TLS encrypted SMTP sessions. </p> 11909 11910 <p> This feature is available in Postfix 2.2 and later. </p> 11911 11912 11913 </DD> 11914 11915 <DT><b><a name="smtpd_sasl_type">smtpd_sasl_type</a> 11916 (default: cyrus)</b></DT><DD> 11917 11918 <p> The SASL plug-in type that the Postfix SMTP server should use 11919 for authentication. The available types are listed with the 11920 "<b>postconf -a</b>" command. </p> 11921 11922 <p> This feature is available in Postfix 2.3 and later. </p> 11923 11924 11925 </DD> 11926 11927 <DT><b><a name="smtpd_sender_login_maps">smtpd_sender_login_maps</a> 11928 (default: empty)</b></DT><DD> 11929 11930 <p> 11931 Optional lookup table with the SASL login names that own sender 11932 (MAIL FROM) addresses. 11933 </p> 11934 11935 <p> 11936 Specify zero or more "<a href="DATABASE_README.html">type:table</a>" lookup tables. With lookups from 11937 indexed files such as DB or DBM, or from networked tables such as 11938 NIS, LDAP or SQL, the following search operations are done with a 11939 sender address of <i>user@domain</i>: </p> 11940 11941 <dl> 11942 11943 <dt> 1) <i>user@domain</i> </dt> 11944 11945 <dd>This table lookup is always done and has the highest precedence. </dd> 11946 11947 <dt> 2) <i>user</i> </dt> 11948 11949 <dd>This table lookup is done only when the <i>domain</i> part of the 11950 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> 11951 or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. </dd> 11952 11953 <dt> 3) <i>@domain</i> </dt> 11954 11955 <dd>This table lookup is done last and has the lowest precedence. </dd> 11956 11957 </dl> 11958 11959 <p> 11960 In all cases the result of table lookup must be either "not found" 11961 or a list of SASL login names separated by comma and/or whitespace. 11962 </p> 11963 11964 11965 </DD> 11966 11967 <DT><b><a name="smtpd_sender_restrictions">smtpd_sender_restrictions</a> 11968 (default: empty)</b></DT><DD> 11969 11970 <p> 11971 Optional restrictions that the Postfix SMTP server applies in the 11972 context of the MAIL FROM command. 11973 See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access 11974 restriction lists" for a discussion of evaluation context and time. 11975 </p> 11976 11977 <p> 11978 The default is to permit everything. 11979 </p> 11980 11981 <p> 11982 Specify a list of restrictions, separated by commas and/or whitespace. 11983 Continue long lines by starting the next line with whitespace. 11984 Restrictions are applied in the order as specified; the first 11985 restriction that matches wins. 11986 </p> 11987 11988 <p> 11989 The following restrictions are specific to the sender address 11990 received with the MAIL FROM command. 11991 </p> 11992 11993 <dl> 11994 11995 <dt><b><a name="check_sender_access">check_sender_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt> 11996 11997 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MAIL FROM 11998 address, domain, parent domains, or localpart@, and execute the 11999 corresponding action. </dd> 12000 12001 <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> 12002 12003 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for 12004 the MAIL FROM address, and execute the corresponding action. Note: 12005 a result of "OK" is not allowed for safety reasons. Instead, use 12006 DUNNO in order to exclude specific hosts from blacklists. This 12007 feature is available in Postfix 2.1 and later. </dd> 12008 12009 <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> 12010 12011 <dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers 12012 for the MAIL FROM address, and execute the corresponding action. 12013 Note: a result of "OK" is not allowed for safety reasons. Instead, 12014 use DUNNO in order to exclude specific hosts from blacklists. This 12015 feature is available in Postfix 2.1 and later. </dd> 12016 12017 <dt><b><a name="reject_authenticated_sender_login_mismatch">reject_authenticated_sender_login_mismatch</a></b></dt> 12018 12019 <dd>Enforces the <a href="postconf.5.html#reject_sender_login_mismatch">reject_sender_login_mismatch</a> restriction for 12020 authenticated clients only. This feature is available in 12021 Postfix version 2.1 and later. </dd> 12022 12023 <dt><b><a name="reject_non_fqdn_sender">reject_non_fqdn_sender</a></b></dt> 12024 12025 <dd>Reject the request when the MAIL FROM address is not in 12026 fully-qualified domain form, as required by the RFC. <br> The 12027 <a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> parameter specifies the response code for 12028 rejected requests (default: 504). </dd> 12029 12030 <dt><b><a name="reject_rhsbl_sender">reject_rhsbl_sender <i>rbl_domain=d.d.d.d</i></a></b></dt> 12031 12032 <dd>Reject the request when the MAIL FROM domain is listed with 12033 the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> (Postfix 12034 version 2.1 and later only). If no "<i>=d.d.d.d</i>" is specified, 12035 reject the request when the MAIL FROM domain is 12036 listed with any A record under <i>rbl_domain</i>. <br> The 12037 <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> parameter specifies the response code for 12038 rejected requests (default: 554); the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> parameter 12039 specifies the default server reply; and the <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> parameter 12040 specifies tables with server replies indexed by <i>rbl_domain</i>. 12041 This feature is available in Postfix 2.0 and later.</dd> 12042 12043 <dt><b><a name="reject_sender_login_mismatch">reject_sender_login_mismatch</a></b></dt> 12044 12045 <dd>Reject the request when $<a href="postconf.5.html#smtpd_sender_login_maps">smtpd_sender_login_maps</a> specifies an 12046 owner for the MAIL FROM address, but the client is not (SASL) logged 12047 in as that MAIL FROM address owner; or when the client is (SASL) 12048 logged in, but the client login name doesn't own the MAIL FROM 12049 address according to $<a href="postconf.5.html#smtpd_sender_login_maps">smtpd_sender_login_maps</a>.</dd> 12050 12051 <dt><b><a name="reject_unauthenticated_sender_login_mismatch">reject_unauthenticated_sender_login_mismatch</a></b></dt> 12052 12053 <dd>Enforces the <a href="postconf.5.html#reject_sender_login_mismatch">reject_sender_login_mismatch</a> restriction for 12054 unauthenticated clients only. This feature is available in 12055 Postfix version 2.1 and later. </dd> 12056 12057 <dt><b><a name="reject_unknown_sender_domain">reject_unknown_sender_domain</a></b></dt> 12058 12059 <dd>Reject the request when Postfix is not final destination for 12060 the sender address, and the MAIL FROM address has no DNS A or MX 12061 record, or when it has a malformed MX record such as a record with 12062 a zero-length MX hostname (Postfix version 2.3 and later). <br> The 12063 <a href="postconf.5.html#unknown_address_reject_code">unknown_address_reject_code</a> parameter specifies the numerical 12064 response code for rejected requests (default: 450). The response 12065 is always 450 in case of a temporary DNS error. <br> The 12066 <a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a> parameter specifies the action 12067 after a temporary DNS error (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). </dd> 12068 12069 <dt><b><a name="reject_unlisted_sender">reject_unlisted_sender</a></b></dt> 12070 12071 <dd>Reject the request when the MAIL FROM address is not listed in 12072 the list of valid recipients for its domain class. See the 12073 <a href="postconf.5.html#smtpd_reject_unlisted_sender">smtpd_reject_unlisted_sender</a> parameter description for details. 12074 This feature is available in Postfix 2.1 and later.</dd> 12075 12076 <dt><b><a name="reject_unverified_sender">reject_unverified_sender</a></b></dt> 12077 12078 <dd>Reject the request when mail to the MAIL FROM address is known to 12079 bounce, or when the sender address destination is not reachable. 12080 Address verification information is managed by the <a href="verify.8.html">verify(8)</a> server; 12081 see the <a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VERIFICATION_README</a> file for details. <br> The 12082 <a href="postconf.5.html#unverified_sender_reject_code">unverified_sender_reject_code</a> parameter specifies the numerical 12083 response code when an address is known to bounce (default: 450, 12084 change into 550 when you are confident that it is safe to do so). 12085 <br>The <a href="postconf.5.html#unverified_sender_defer_code">unverified_sender_defer_code</a> specifies the numerical response 12086 code when an address address probe failed due to a temporary problem 12087 (default: 450). <br> The <a href="postconf.5.html#unverified_sender_tempfail_action">unverified_sender_tempfail_action</a> parameter 12088 specifies the action after address probe failure due to a temporary 12089 problem (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). <br> This feature is available 12090 in Postfix 2.1 and later. </dd> 12091 12092 </dl> 12093 12094 <p> 12095 Other restrictions that are valid in this context: 12096 </p> 12097 12098 <ul> 12099 12100 <li> <a href="#generic">Generic</a> restrictions that can be used 12101 in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>. 12102 12103 <li> SMTP command specific restrictions described under 12104 <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>. 12105 12106 <li> SMTP command specific restrictions described under 12107 <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>. When recipient restrictions are listed 12108 under <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>, they have effect only with 12109 "<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 12110 evaluated at the time of the RCPT TO command. 12111 12112 </ul> 12113 12114 <p> 12115 Examples: 12116 </p> 12117 12118 <pre> 12119 <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> 12120 <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>, 12121 <a href="postconf.5.html#check_sender_access">check_sender_access</a> hash:/etc/postfix/access 12122 </pre> 12123 12124 12125 </DD> 12126 12127 <DT><b><a name="smtpd_soft_error_limit">smtpd_soft_error_limit</a> 12128 (default: 10)</b></DT><DD> 12129 12130 <p> 12131 The number of errors a remote SMTP client is allowed to make without 12132 delivering mail before the Postfix SMTP server slows down all its 12133 responses. 12134 </p> 12135 12136 <ul> 12137 12138 <li><p>With Postfix version 2.1 and later, the Postfix SMTP server 12139 delays all responses by $<a href="postconf.5.html#smtpd_error_sleep_time">smtpd_error_sleep_time</a> seconds. </p> 12140 12141 <li><p>With Postfix versions 2.0 and earlier, the Postfix SMTP 12142 server delays all responses by (number of errors) seconds. </p> 12143 12144 </ul> 12145 12146 12147 </DD> 12148 12149 <DT><b><a name="smtpd_starttls_timeout">smtpd_starttls_timeout</a> 12150 (default: 300s)</b></DT><DD> 12151 12152 <p> The time limit for Postfix SMTP server write and read operations 12153 during TLS startup and shutdown handshake procedures. </p> 12154 12155 <p> This feature is available in Postfix 2.2 and later. </p> 12156 12157 12158 </DD> 12159 12160 <DT><b><a name="smtpd_timeout">smtpd_timeout</a> 12161 (default: normal: 300s, stress: 10s)</b></DT><DD> 12162 12163 <p> 12164 The time limit for sending a Postfix SMTP server response and for 12165 receiving a remote SMTP client request. Normally the default limit 12166 is 300s, but it changes under overload to just 10s with Postfix 2.6 12167 and later. 12168 </p> 12169 12170 <p> 12171 Note: if you set SMTP time limits to very large values you may have 12172 to update the global <a href="postconf.5.html#ipc_timeout">ipc_timeout</a> parameter. 12173 </p> 12174 12175 <p> 12176 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 12177 The default time unit is s (seconds). 12178 </p> 12179 12180 12181 </DD> 12182 12183 <DT><b><a name="smtpd_tls_CAfile">smtpd_tls_CAfile</a> 12184 (default: empty)</b></DT><DD> 12185 12186 <p> A file containing (PEM format) CA certificates of root CAs trusted 12187 to sign either remote SMTP client certificates or intermediate CA 12188 certificates. These are loaded into memory before the <a href="smtpd.8.html">smtpd(8)</a> server 12189 enters the chroot jail. If the number of trusted roots is large, consider 12190 using <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> instead, but note that the latter directory must 12191 be present in the chroot jail if the <a href="smtpd.8.html">smtpd(8)</a> server is chrooted. This 12192 file may also be used to augment the server certificate trust chain, 12193 but it is best to include all the required certificates directly in the 12194 server certificate file. </p> 12195 12196 <p> By default (see <a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>), client certificates are not 12197 requested, and <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> should remain empty. If you do make use 12198 of client certificates, the distinguished names (DNs) of the certificate 12199 authorities listed in <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> are sent to the remote SMTP client 12200 in the client certificate request message. MUAs with multiple client 12201 certificates may use the list of preferred certificate authorities 12202 to select the correct client certificate. You may want to put your 12203 "preferred" CA or CAs in this file, and install other trusted CAs in 12204 $<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>. </p> 12205 12206 <p> Example: </p> 12207 12208 <pre> 12209 <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> = /etc/postfix/CAcert.pem 12210 </pre> 12211 12212 <p> This feature is available in Postfix 2.2 and later. </p> 12213 12214 12215 </DD> 12216 12217 <DT><b><a name="smtpd_tls_CApath">smtpd_tls_CApath</a> 12218 (default: empty)</b></DT><DD> 12219 12220 <p> A directory containing (PEM format) CA certificates of root CAs 12221 trusted to sign either remote SMTP client certificates or intermediate CA 12222 certificates. Do not forget to create the necessary "hash" links with, 12223 for example, "$OPENSSL_HOME/bin/c_rehash /etc/postfix/certs". To use 12224 <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> in chroot mode, this directory (or a copy) must be 12225 inside the chroot jail. </p> 12226 12227 <p> By default (see <a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>), client certificates are 12228 not requested, and <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> should remain empty. In contrast 12229 to <a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a>, DNs of certificate authorities installed 12230 in $<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> are not included in the client certificate 12231 request message. MUAs with multiple client certificates may use the 12232 list of preferred certificate authorities to select the correct 12233 client certificate. You may want to put your "preferred" CA or 12234 CAs in $<a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a>, and install the remaining trusted CAs in 12235 $<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>. </p> 12236 12237 <p> Example: </p> 12238 12239 <pre> 12240 <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> = /etc/postfix/certs 12241 </pre> 12242 12243 <p> This feature is available in Postfix 2.2 and later. </p> 12244 12245 12246 </DD> 12247 12248 <DT><b><a name="smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a> 12249 (default: yes)</b></DT><DD> 12250 12251 <p> Force the Postfix SMTP server to issue a TLS session id, even 12252 when TLS session caching is turned off (<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> 12253 is empty). This behavior is compatible with Postfix < 2.3. </p> 12254 12255 <p> With Postfix 2.3 and later the Postfix SMTP server can disable 12256 session id generation when TLS session caching is turned off. This 12257 keeps clients from caching sessions that almost certainly cannot 12258 be re-used. </p> 12259 12260 <p> By default, the Postfix SMTP server always generates TLS session 12261 ids. This works around a known defect in mail client applications 12262 such as MS Outlook, and may also prevent interoperability issues 12263 with other MTAs. </p> 12264 12265 <p> Example: </p> 12266 12267 <pre> 12268 <a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a> = no 12269 </pre> 12270 12271 <p> This feature is available in Postfix 2.3 and later. </p> 12272 12273 12274 </DD> 12275 12276 <DT><b><a name="smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a> 12277 (default: no)</b></DT><DD> 12278 12279 <p> Ask a remote SMTP client for a client certificate. This 12280 information is needed for certificate based mail relaying with, 12281 for example, the <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> feature. </p> 12282 12283 <p> Some clients such as Netscape will either complain if no 12284 certificate is available (for the list of CAs in $<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>) 12285 or will offer multiple client certificates to choose from. This 12286 may be annoying, so this option is "off" by default. </p> 12287 12288 <p> This feature is available in Postfix 2.2 and later. </p> 12289 12290 12291 </DD> 12292 12293 <DT><b><a name="smtpd_tls_auth_only">smtpd_tls_auth_only</a> 12294 (default: no)</b></DT><DD> 12295 12296 <p> When TLS encryption is optional in the Postfix SMTP server, do 12297 not announce or accept SASL authentication over unencrypted 12298 connections. </p> 12299 12300 <p> This feature is available in Postfix 2.2 and later. </p> 12301 12302 12303 </DD> 12304 12305 <DT><b><a name="smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a> 12306 (default: 9)</b></DT><DD> 12307 12308 <p> The verification depth for remote SMTP client certificates. A 12309 depth of 1 is sufficient if the issuing CA is listed in a local CA 12310 file. </p> 12311 12312 <p> The default verification depth is 9 (the OpenSSL default) for 12313 compatibility with earlier Postfix behavior. Prior to Postfix 2.5, 12314 the default value was 5, but the limit was not actually enforced. If 12315 you have set this to a lower non-default value, certificates with longer 12316 trust chains may now fail to verify. Certificate chains with 1 or 2 12317 CAs are common, deeper chains are more rare and any number between 5 12318 and 9 should suffice in practice. You can choose a lower number if, 12319 for example, you trust certificates directly signed by an issuing CA 12320 but not any CAs it delegates to. </p> 12321 12322 <p> This feature is available in Postfix 2.2 and later. </p> 12323 12324 12325 </DD> 12326 12327 <DT><b><a name="smtpd_tls_cert_file">smtpd_tls_cert_file</a> 12328 (default: empty)</b></DT><DD> 12329 12330 <p> File with the Postfix SMTP server RSA certificate in PEM format. 12331 This file may also contain the Postfix SMTP server private RSA key. </p> 12332 12333 <p> Public Internet MX hosts without certificates signed by a "reputable" 12334 CA must generate, and be prepared to present to most clients, a 12335 self-signed or private-CA signed certificate. The client will not be 12336 able to authenticate the server, but unless it is running Postfix 2.3 or 12337 similar software, it will still insist on a server certificate. </p> 12338 12339 <p> For servers that are <b>not</b> public Internet MX hosts, Postfix 12340 2.3 supports configurations with no certificates. This entails the 12341 use of just the anonymous TLS ciphers, which are not supported by 12342 typical SMTP clients. Since such clients will not, as a rule, fall 12343 back to plain text after a TLS handshake failure, the server will 12344 be unable to receive email from TLS enabled clients. To avoid 12345 accidental configurations with no certificates, Postfix 2.3 enables 12346 certificate-less operation only when the administrator explicitly 12347 sets "<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> = none". This ensures that new Postfix 12348 configurations will not accidentally run with no certificates. </p> 12349 12350 <p> Both RSA and DSA certificates are supported. When both types 12351 are present, the cipher used determines which certificate will be 12352 presented to the client. For Netscape and OpenSSL clients without 12353 special cipher choices the RSA certificate is preferred. </p> 12354 12355 <p> To enable a remote SMTP client to verify the Postfix SMTP server 12356 certificate, the issuing CA certificates must be made available to the 12357 client. You should include the required certificates in the server 12358 certificate file, the server certificate first, then the issuing 12359 CA(s) (bottom-up order). </p> 12360 12361 <p> Example: the certificate for "server.example.com" was issued by 12362 "intermediate CA" which itself has a certificate of "root CA". 12363 Create the server.pem file with "cat server_cert.pem intermediate_CA.pem 12364 root_CA.pem > server.pem". </p> 12365 12366 <p> If you also want to verify client certificates issued by these 12367 CAs, you can add the CA certificates to the <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>, in which 12368 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 12369 <a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>. </p> 12370 12371 <p> A certificate supplied here must be usable as an SSL server certificate 12372 and hence pass the "openssl verify -purpose sslserver ..." test. </p> 12373 12374 <p> Example: </p> 12375 12376 <pre> 12377 <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> = /etc/postfix/server.pem 12378 </pre> 12379 12380 <p> This feature is available in Postfix 2.2 and later. </p> 12381 12382 12383 </DD> 12384 12385 <DT><b><a name="smtpd_tls_cipherlist">smtpd_tls_cipherlist</a> 12386 (default: empty)</b></DT><DD> 12387 12388 <p> Obsolete Postfix < 2.3 control for the Postfix SMTP server TLS 12389 cipher list. It is easy to create inter-operability problems by choosing 12390 a non-default cipher list. Do not use a non-default TLS cipherlist for 12391 MX hosts on the public Internet. Clients that begin the TLS handshake, 12392 but are unable to agree on a common cipher, may not be able to send any 12393 email to the SMTP server. Using a restricted cipher list may be more 12394 appropriate for a dedicated MSA or an internal mailhub, where one can 12395 exert some control over the TLS software and settings of the connecting 12396 clients. </p> 12397 12398 <p> <b>Note:</b> do not use "" quotes around the parameter value. </p> 12399 12400 <p>This feature is available with Postfix version 2.2. It is not used with 12401 Postfix 2.3 and later; use <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> instead. </p> 12402 12403 12404 </DD> 12405 12406 <DT><b><a name="smtpd_tls_ciphers">smtpd_tls_ciphers</a> 12407 (default: export)</b></DT><DD> 12408 12409 <p> The minimum TLS cipher grade that the Postfix SMTP server 12410 will use with opportunistic TLS encryption. Cipher types listed in 12411 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> are excluded from the base definition of 12412 the selected cipher grade. The default value "export" ensures maximum 12413 inter-operability. Because encryption is optional, stronger controls 12414 are not appropriate, and this setting SHOULD NOT be changed unless the 12415 change is essential. </p> 12416 12417 <p> When TLS is mandatory the cipher grade is chosen via the 12418 <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> configuration parameter, see there for syntax 12419 details. </p> 12420 12421 <p> Example: </p> 12422 <pre> 12423 <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> = export 12424 </pre> 12425 12426 <p> This feature is available in Postfix 2.6 and later. With earlier Postfix 12427 releases only the <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> parameter is implemented, 12428 and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p> 12429 12430 12431 </DD> 12432 12433 <DT><b><a name="smtpd_tls_dcert_file">smtpd_tls_dcert_file</a> 12434 (default: empty)</b></DT><DD> 12435 12436 <p> File with the Postfix SMTP server DSA certificate in PEM format. 12437 This file may also contain the Postfix SMTP server private DSA key. </p> 12438 12439 <p> See the discussion under <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> for more details. 12440 </p> 12441 12442 <p> Example: </p> 12443 12444 <pre> 12445 <a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a> = /etc/postfix/server-dsa.pem 12446 </pre> 12447 12448 <p> This feature is available in Postfix 2.2 and later. </p> 12449 12450 12451 </DD> 12452 12453 <DT><b><a name="smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a> 12454 (default: empty)</b></DT><DD> 12455 12456 <p> File with DH parameters that the Postfix SMTP server should 12457 use with EDH ciphers. </p> 12458 12459 <p> Instead of using the exact same parameter sets as distributed 12460 with other TLS packages, it is more secure to generate your own 12461 set of parameters with something like the following command: </p> 12462 12463 <blockquote> 12464 <pre> 12465 openssl gendh -out /etc/postfix/dh_1024.pem -2 1024 12466 </pre> 12467 </blockquote> 12468 12469 <p> Your actual source for entropy may differ. Some systems have 12470 /dev/random; on other system you may consider using the "Entropy 12471 Gathering Daemon EGD", available at <a href="http://egd.sourceforge.net/">http://egd.sourceforge.net/</a> 12472 </p> 12473 12474 <p> Example: </p> 12475 12476 <pre> 12477 <a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a> = /etc/postfix/dh_1024.pem 12478 </pre> 12479 12480 <p>This feature is available with Postfix version 2.2.</p> 12481 12482 12483 </DD> 12484 12485 <DT><b><a name="smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a> 12486 (default: empty)</b></DT><DD> 12487 12488 <p> File with DH parameters that the Postfix SMTP server should 12489 use with EDH ciphers. </p> 12490 12491 <p> See also the discussion under the <a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a> 12492 configuration parameter. </p> 12493 12494 <p> Example: </p> 12495 12496 <pre> 12497 <a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a> = /etc/postfix/dh_512.pem 12498 </pre> 12499 12500 <p>This feature is available with Postfix version 2.2.</p> 12501 12502 12503 </DD> 12504 12505 <DT><b><a name="smtpd_tls_dkey_file">smtpd_tls_dkey_file</a> 12506 (default: $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>)</b></DT><DD> 12507 12508 <p> File with the Postfix SMTP server DSA private key in PEM format. 12509 This file may be combined with the Postfix SMTP server DSA certificate 12510 file specified with $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>. </p> 12511 12512 <p> The private key must be accessible without a pass-phrase, i.e. it 12513 must not be encrypted. File permissions should grant read-only 12514 access to the system superuser account ("root"), and no access 12515 to anyone else. </p> 12516 12517 <p> This feature is available in Postfix 2.2 and later. </p> 12518 12519 12520 </DD> 12521 12522 <DT><b><a name="smtpd_tls_eccert_file">smtpd_tls_eccert_file</a> 12523 (default: empty)</b></DT><DD> 12524 12525 <p> File with the Postfix SMTP server ECDSA certificate in PEM format. 12526 This file may also contain the Postfix SMTP server private ECDSA key. </p> 12527 12528 <p> See the discussion under <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> for more details. </p> 12529 12530 <p> Example: </p> 12531 12532 <pre> 12533 <a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a> = /etc/postfix/ecdsa-scert.pem 12534 </pre> 12535 12536 <p> This feature is available in Postfix 2.6 and later, when Postfix is 12537 compiled and linked with OpenSSL 0.9.9 or later. </p> 12538 12539 12540 </DD> 12541 12542 <DT><b><a name="smtpd_tls_eckey_file">smtpd_tls_eckey_file</a> 12543 (default: $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>)</b></DT><DD> 12544 12545 <p> File with the Postfix SMTP server ECDSA private key in PEM format. 12546 This file may be combined with the Postfix SMTP server ECDSA certificate 12547 file specified with $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>. </p> 12548 12549 <p> The private key must be accessible without a pass-phrase, i.e. it 12550 must not be encrypted. File permissions should grant read-only 12551 access to the system superuser account ("root"), and no access 12552 to anyone else. </p> 12553 12554 <p> This feature is available in Postfix 2.6 and later, when Postfix is 12555 compiled and linked with OpenSSL 0.9.9 or later. </p> 12556 12557 12558 </DD> 12559 12560 <DT><b><a name="smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> 12561 (default: see "postconf -d" output)</b></DT><DD> 12562 12563 <p> The Postfix SMTP server security grade for ephemeral elliptic-curve 12564 Diffie-Hellman (EECDH) key exchange. </p> 12565 12566 <p> The available choices are: </p> 12567 12568 <dl> 12569 12570 <dt><b>none</b></dt> <dd> Don't use EECDH. Ciphers based on EECDH key 12571 exchange will be disabled. This is the default in official Postfix 12572 releases (<a href="postconf.5.html#mail_version">mail_version</a> = major.minor.patchlevel). </dd> 12573 12574 <dt><b>strong</b></dt> <dd> Use EECDH with approximately 128 12575 bits of security at a reasonable computational cost. This is the 12576 current best-practice trade-off between security and computational 12577 efficiency. This is the default in Postfix snapshot releases 12578 (<a href="postconf.5.html#mail_version">mail_version</a> = major.minor-releasedate). </dd> 12579 12580 <dt><b>ultra</b></dt> <dd> Use EECDH with approximately 192 bits of 12581 security at computational cost that is approximately twice as high 12582 as 128 bit strength ECC. Barring significant progress in attacks on 12583 elliptic curve crypto-systems, the "strong" curve is sufficient for most 12584 users. </dd> 12585 12586 </dl> 12587 12588 <p> This feature is available in Postfix 2.6 and later, when it is 12589 compiled and linked with OpenSSL 0.9.9 or later. </p> 12590 12591 12592 </DD> 12593 12594 <DT><b><a name="smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> 12595 (default: empty)</b></DT><DD> 12596 12597 <p> List of ciphers or cipher types to exclude from the SMTP server 12598 cipher list at all TLS security levels. Excluding valid ciphers 12599 can create interoperability problems. DO NOT exclude ciphers unless it 12600 is essential to do so. This is not an OpenSSL cipherlist; it is a simple 12601 list separated by whitespace and/or commas. The elements are a single 12602 cipher, or one or more "+" separated cipher properties, in which case 12603 only ciphers matching <b>all</b> the properties are excluded. </p> 12604 12605 <p> Examples (some of these will cause problems): </p> 12606 12607 <blockquote> 12608 <pre> 12609 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = aNULL 12610 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = MD5, DES 12611 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = DES+MD5 12612 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = AES256-SHA, DES-CBC3-MD5 12613 <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = kEDH+aRSA 12614 </pre> 12615 </blockquote> 12616 12617 <p> The first setting disables anonymous ciphers. The next setting 12618 disables ciphers that use the MD5 digest algorithm or the (single) DES 12619 encryption algorithm. The next setting disables ciphers that use MD5 and 12620 DES together. The next setting disables the two ciphers "AES256-SHA" 12621 and "DES-CBC3-MD5". The last setting disables ciphers that use "EDH" 12622 key exchange with RSA authentication. </p> 12623 12624 <p> This feature is available in Postfix 2.3 and later. </p> 12625 12626 12627 </DD> 12628 12629 <DT><b><a name="smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> 12630 (default: md5)</b></DT><DD> 12631 12632 <p> The message digest algorithm used to construct client-certificate 12633 fingerprints for <b><a href="postconf.5.html#check_ccert_access">check_ccert_access</a></b> and 12634 <b><a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a></b>. The default algorithm is <b>md5</b>, 12635 for backwards compatibility with Postfix releases prior to 2.5. 12636 </p> 12637 12638 <p> The best practice algorithm is now <b>sha1</b>. Recent advances in hash 12639 function cryptanalysis have led to md5 being deprecated in favor of sha1. 12640 However, as long as there are no known "second pre-image" attacks 12641 against md5, its use in this context can still be considered safe. 12642 </p> 12643 12644 <p> While additional digest algorithms are often available with OpenSSL's 12645 libcrypto, only those used by libssl in SSL cipher suites are available to 12646 Postfix. For now this means just md5 or sha1. </p> 12647 12648 <p> To find the fingerprint of a specific certificate file, with a 12649 specific digest algorithm, run: </p> 12650 12651 <blockquote> 12652 <pre> 12653 $ openssl x509 -noout -fingerprint -<i>digest</i> -in <i>certfile</i>.pem 12654 </pre> 12655 </blockquote> 12656 12657 <p> The text to the right of "=" sign is the desired fingerprint. 12658 For example: </p> 12659 12660 <blockquote> 12661 <pre> 12662 $ openssl x509 -noout -fingerprint -sha1 -in cert.pem 12663 SHA1 Fingerprint=D4:6A:AB:19:24:79:F8:32:BB:A6:CB:66:82:C0:8E:9B:EE:29:A8:1A 12664 </pre> 12665 </blockquote> 12666 12667 <p> Example: client-certificate access table, with sha1 fingerprints: </p> 12668 12669 <blockquote> 12670 <pre> 12671 /etc/postfix/<a href="postconf.5.html">main.cf</a>: 12672 <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> = sha1 12673 <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> = 12674 <a href="postconf.5.html#check_ccert_access">check_ccert_access</a> hash:/etc/postfix/access, 12675 reject 12676 </pre> 12677 <pre> 12678 /etc/postfix/access: 12679 # Action folded to next line... 12680 AF:88:7C:AD:51:95:6F:36:96:F6:01:FB:2E:48:CD:AB:49:25:A2:3B 12681 OK 12682 85:16:78:FD:73:6E:CE:70:E0:31:5F:0D:3C:C8:6D:C4:2C:24:59:E1 12683 <a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a> 12684 </pre> 12685 </blockquote> 12686 12687 <p> This feature is available in Postfix 2.5 and later. </p> 12688 12689 12690 </DD> 12691 12692 <DT><b><a name="smtpd_tls_key_file">smtpd_tls_key_file</a> 12693 (default: $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>)</b></DT><DD> 12694 12695 <p> File with the Postfix SMTP server RSA private key in PEM format. 12696 This file may be combined with the Postfix SMTP server RSA certificate 12697 file specified with $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>. </p> 12698 12699 <p> The private key must be accessible without a pass-phrase, i.e. it 12700 must not be encrypted. File permissions should grant read-only 12701 access to the system superuser account ("root"), and no access 12702 to anyone else. </p> 12703 12704 12705 </DD> 12706 12707 <DT><b><a name="smtpd_tls_loglevel">smtpd_tls_loglevel</a> 12708 (default: 0)</b></DT><DD> 12709 12710 <p> Enable additional Postfix SMTP server logging of TLS activity. 12711 Each logging level also includes the information that is logged at 12712 a lower logging level. </p> 12713 12714 <dl compact> 12715 12716 <dt> </dt> <dd> 0 Disable logging of TLS activity. </dd> 12717 12718 <dt> </dt> <dd> 1 Log TLS handshake and certificate information. </dd> 12719 12720 <dt> </dt> <dd> 2 Log levels during TLS negotiation. </dd> 12721 12722 <dt> </dt> <dd> 3 Log hexadecimal and ASCII dump of TLS negotiation 12723 process. </dd> 12724 12725 <dt> </dt> <dd> 4 Also log hexadecimal and ASCII dump of complete 12726 transmission after STARTTLS. </dd> 12727 12728 </dl> 12729 12730 <p> Use "<a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a> = 3" only in case of problems. Use of 12731 loglevel 4 is strongly discouraged. </p> 12732 12733 <p> This feature is available in Postfix 2.2 and later. </p> 12734 12735 12736 </DD> 12737 12738 <DT><b><a name="smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> 12739 (default: medium)</b></DT><DD> 12740 12741 <p> The minimum TLS cipher grade that the Postfix SMTP server 12742 will use with mandatory TLS encryption. Cipher types listed in 12743 <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 12744 excluded from the base definition of the selected cipher grade. See 12745 <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> for cipher controls that apply to opportunistic 12746 TLS. </p> 12747 12748 <p> The following cipher grades are supported: </p> 12749 12750 <dl> 12751 <dt><b>export</b></dt> 12752 <dd> Enable the mainstream "EXPORT" grade or better OpenSSL ciphers. 12753 This is the most appropriate setting for public MX hosts, and is always 12754 used with opportunistic TLS encryption. The underlying cipherlist 12755 is specified via the <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> configuration parameter, 12756 which you are strongly encouraged to not change. The default value 12757 of <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> includes anonymous ciphers, but these are 12758 automatically filtered out if the server is configured to ask for 12759 client certificates. If you must always exclude anonymous ciphers, 12760 set "<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = aNULL". To exclude anonymous ciphers 12761 only when TLS is enforced, set "<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> = 12762 aNULL". </dd> 12763 12764 <dt><b>low</b></dt> 12765 <dd> Enable the mainstream "LOW" grade or better OpenSSL ciphers. The 12766 underlying cipherlist is specified via the <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> 12767 configuration parameter, which you are strongly encouraged to 12768 not change. The default value of <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> includes 12769 anonymous ciphers, but these are automatically filtered out if the 12770 server is configured to ask for client certificates. If you must 12771 always exclude anonymous ciphers, set "<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = 12772 aNULL". To exclude anonymous ciphers only when TLS is enforced, set 12773 "<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> = aNULL". </dd> 12774 12775 <dt><b>medium</b></dt> 12776 <dd> Enable the mainstream "MEDIUM" grade or better OpenSSL ciphers. These 12777 are essentially the 128-bit or stronger ciphers. This is the default 12778 minimum strength for mandatory TLS encryption. MSAs that enforce 12779 TLS and have clients that do not support any "MEDIUM" or "HIGH" 12780 grade ciphers, may need to configure a weaker ("low" or "export") 12781 minimum cipher grade. The underlying cipherlist is specified via the 12782 <a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> configuration parameter, which you are strongly 12783 encouraged to not change. The default value of <a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> 12784 includes anonymous ciphers, but these are automatically filtered out if 12785 the server is configured to ask for client certificates. If you must 12786 always exclude anonymous ciphers, set "<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = 12787 aNULL". To exclude anonymous ciphers only when TLS is enforced, set 12788 "<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> = aNULL". </dd> 12789 12790 <dt><b>high</b></dt> 12791 <dd> Enable only the mainstream "HIGH" grade OpenSSL ciphers. The 12792 underlying cipherlist is specified via the <a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a> 12793 configuration parameter, which you are strongly encouraged to 12794 not change. The default value of <a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a> includes 12795 anonymous ciphers, but these are automatically filtered out if the 12796 server is configured to ask for client certificates. If you must 12797 always exclude anonymous ciphers, set "<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = 12798 aNULL". To exclude anonymous ciphers only when TLS is enforced, set 12799 "<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> = aNULL". </dd> 12800 12801 <dt><b>null</b></dt> 12802 <dd> Enable only the "NULL" OpenSSL ciphers, these provide authentication 12803 without encryption. This setting is only appropriate in the rare 12804 case that all clients are prepared to use NULL ciphers (not normally 12805 enabled in TLS clients). The underlying cipherlist is specified via the 12806 <a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a> configuration parameter, which you are strongly 12807 encouraged to not change. The default value of <a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a> 12808 excludes anonymous ciphers (OpenSSL 0.9.8 has NULL ciphers that offer 12809 data integrity without encryption or authentication). </dd> 12810 12811 </dl> 12812 12813 <p> This feature is available in Postfix 2.3 and later. </p> 12814 12815 12816 </DD> 12817 12818 <DT><b><a name="smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> 12819 (default: empty)</b></DT><DD> 12820 12821 <p> Additional list of ciphers or cipher types to exclude from the 12822 SMTP server cipher list at mandatory TLS security levels. This list 12823 works in addition to the exclusions listed with <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> 12824 (see there for syntax details). </p> 12825 12826 <p> This feature is available in Postfix 2.3 and later. </p> 12827 12828 12829 </DD> 12830 12831 <DT><b><a name="smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> 12832 (default: SSLv3, TLSv1)</b></DT><DD> 12833 12834 <p> The SSL/TLS protocols accepted by the Postfix SMTP server with 12835 mandatory TLS encryption. If the list is empty, the server supports all 12836 available SSL/TLS protocol versions. A non-empty value is a list 12837 of protocol 12838 names separated by whitespace, commas or colons. The supported protocol 12839 names are "SSLv2", "SSLv3" and "TLSv1", and are not case sensitive. </p> 12840 12841 <p> With Postfix ≥ 2.5 the parameter syntax is expanded to support 12842 protocol exclusions. One can now explicitly exclude SSLv2 by setting 12843 "<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = !SSLv2". To exclude both SSLv2 and 12844 SSLv3 set "<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = !SSLv2, !SSLv3". Listing 12845 the protocols to include, rather than protocols to exclude, is still 12846 supported, use the form you find more intuitive. </p> 12847 12848 <p> Since SSL version 2 has known protocol weaknesses and is now 12849 deprecated, the default setting excludes "SSLv2". This means that 12850 by default, SSL version 2 will not be used at the "encrypt" security 12851 level. </p> 12852 12853 <p> Example: </p> 12854 12855 <pre> 12856 <a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = TLSv1 12857 # Alternative form with Postfix ≥ 2.5: 12858 <a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = !SSLv2, !SSLv3 12859 </pre> 12860 12861 <p> This feature is available in Postfix 2.3 and later. </p> 12862 12863 12864 </DD> 12865 12866 <DT><b><a name="smtpd_tls_protocols">smtpd_tls_protocols</a> 12867 (default: empty)</b></DT><DD> 12868 12869 <p> List of TLS protocols that the Postfix SMTP server will exclude 12870 or include with opportunistic TLS encryption. This parameter SHOULD be 12871 left at its default empty value, allowing all protocols to be used with 12872 opportunistic TLS. </p> 12873 12874 <p> In <a href="postconf.5.html">main.cf</a> the values are separated by whitespace, commas or 12875 colons. An empty value means allow all protocols. The valid protocol 12876 names, (see <b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" and 12877 "TLSv1". In <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> table entries, "protocols" attribute 12878 values are separated by a colon. </p> 12879 12880 <p> To include a protocol list its name, to exclude it, prefix the name 12881 with a "!" character. To exclude SSLv2 even for opportunistic TLS set 12882 "<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2". To exclude both "SSLv2" and "SSLv3" set 12883 "<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2, !SSLv3". Explicitly listing the protocols to 12884 include, is supported, but not recommended. OpenSSL provides no mechanisms 12885 for excluding protocols not known at compile-time. If Postfix is linked 12886 against an OpenSSL library that supports additional protocol versions, 12887 they cannot be excluded using either syntax. </p> 12888 12889 <p> Example: </p> 12890 <pre> 12891 <a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2 12892 </pre> 12893 12894 <p> This feature is available in Postfix 2.6 and later. </p> 12895 12896 12897 </DD> 12898 12899 <DT><b><a name="smtpd_tls_received_header">smtpd_tls_received_header</a> 12900 (default: no)</b></DT><DD> 12901 12902 <p> Request that the Postfix SMTP server produces Received: message 12903 headers that include information about the protocol and cipher used, 12904 as well as the client CommonName and client certificate issuer 12905 CommonName. This is disabled by default, as the information may 12906 be modified in transit through other mail servers. Only information 12907 that was recorded by the final destination can be trusted. </p> 12908 12909 <p> This feature is available in Postfix 2.2 and later. </p> 12910 12911 12912 </DD> 12913 12914 <DT><b><a name="smtpd_tls_req_ccert">smtpd_tls_req_ccert</a> 12915 (default: no)</b></DT><DD> 12916 12917 <p> With mandatory TLS encryption, require a trusted remote SMTP client 12918 certificate in order to allow TLS connections to proceed. This 12919 option implies "<a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a> = yes". </p> 12920 12921 <p> When TLS encryption is optional, this setting is ignored with 12922 a warning written to the mail log. </p> 12923 12924 <p> This feature is available in Postfix 2.2 and later. </p> 12925 12926 12927 </DD> 12928 12929 <DT><b><a name="smtpd_tls_security_level">smtpd_tls_security_level</a> 12930 (default: empty)</b></DT><DD> 12931 12932 <p> The SMTP TLS security level for the Postfix SMTP server; when 12933 a non-empty value is specified, this overrides the obsolete parameters 12934 <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 12935 "<a href="postconf.5.html#smtpd_tls_wrappermode">smtpd_tls_wrappermode</a> = yes". </p> 12936 12937 <p> Specify one of the following security levels: </p> 12938 12939 <dl> 12940 12941 <dt><b>none</b></dt> <dd> TLS will not be used. </dd> 12942 12943 <dt><b>may</b></dt> <dd> Opportunistic TLS: announce STARTTLS support 12944 to SMTP clients, but do not require that clients use TLS encryption. 12945 </dd> 12946 12947 <dt><b>encrypt</b></dt> <dd>Mandatory TLS encryption: announce 12948 STARTTLS support to SMTP clients, and require that clients use TLS 12949 encryption. According to <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> this MUST NOT be applied in case 12950 of a publicly-referenced SMTP server. Instead, this option should 12951 be used only on dedicated servers. </dd> 12952 12953 </dl> 12954 12955 <p> Note 1: the "fingerprint", "verify" and "secure" levels are not 12956 supported here. 12957 The Postfix SMTP server logs a warning and uses "encrypt" instead. 12958 To verify SMTP client certificates, see <a href="TLS_README.html">TLS_README</a> for a discussion 12959 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> 12960 features. </p> 12961 12962 <p> Note 2: The parameter setting "<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> = 12963 encrypt" implies "<a href="postconf.5.html#smtpd_tls_auth_only">smtpd_tls_auth_only</a> = yes".</p> 12964 12965 <p> Note 3: when invoked via "sendmail -bs", Postfix will never 12966 offer STARTTLS due to insufficient privileges to access the server 12967 private key. This is intended behavior.</p> 12968 12969 <p> This feature is available in Postfix 2.3 and later. </p> 12970 12971 12972 </DD> 12973 12974 <DT><b><a name="smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> 12975 (default: empty)</b></DT><DD> 12976 12977 <p> Name of the file containing the optional Postfix SMTP server 12978 TLS session cache. Specify a database type that supports enumeration, 12979 such as <b>btree</b> or <b>sdbm</b>; there is no need to support 12980 concurrent access. The file is created if it does not exist. The <a href="smtpd.8.html">smtpd(8)</a> 12981 daemon does not use this parameter directly, rather the cache is 12982 implemented indirectly in the <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon. This means that 12983 per-smtpd-instance <a href="master.5.html">master.cf</a> overrides of this parameter are not 12984 effective. Note, that each of the cache databases supported by <a href="tlsmgr.8.html">tlsmgr(8)</a> 12985 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> 12986 (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 12987 stored separately. It is not at this time possible to store multiple 12988 caches in a single database. </p> 12989 12990 <p> Note: <b>dbm</b> databases are not suitable. TLS 12991 session objects are too large. </p> 12992 12993 <p> As of version 2.5, Postfix no longer uses root privileges when 12994 opening this file. The file should now be stored under the Postfix-owned 12995 <a href="postconf.5.html#data_directory">data_directory</a>. As a migration aid, an attempt to open the file 12996 under a non-Postfix directory is redirected to the Postfix-owned 12997 <a href="postconf.5.html#data_directory">data_directory</a>, and a warning is logged. </p> 12998 12999 <p> Example: </p> 13000 13001 <pre> 13002 <a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> = btree:/var/lib/postfix/smtpd_scache 13003 </pre> 13004 13005 <p> This feature is available in Postfix 2.2 and later. </p> 13006 13007 13008 </DD> 13009 13010 <DT><b><a name="smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a> 13011 (default: 3600s)</b></DT><DD> 13012 13013 <p> The expiration time of Postfix SMTP server TLS session cache 13014 information. A cache cleanup is performed periodically 13015 every $<a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a> seconds. As with 13016 $<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a>, this parameter is implemented in the 13017 <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon and therefore per-smtpd-instance <a href="master.5.html">master.cf</a> overrides 13018 are not possible. </p> 13019 13020 <p> This feature is available in Postfix 2.2 and later. </p> 13021 13022 13023 </DD> 13024 13025 <DT><b><a name="smtpd_tls_wrappermode">smtpd_tls_wrappermode</a> 13026 (default: no)</b></DT><DD> 13027 13028 <p> Run the Postfix SMTP server in the non-standard "wrapper" mode, 13029 instead of using the STARTTLS command. </p> 13030 13031 <p> If you want to support this service, enable a special port in 13032 <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 13033 server's command line. Port 465 (smtps) was once chosen for this 13034 purpose. </p> 13035 13036 <p> This feature is available in Postfix 2.2 and later. </p> 13037 13038 13039 </DD> 13040 13041 <DT><b><a name="smtpd_use_tls">smtpd_use_tls</a> 13042 (default: no)</b></DT><DD> 13043 13044 <p> Opportunistic TLS: announce STARTTLS support to SMTP clients, 13045 but do not require that clients use TLS encryption. </p> 13046 13047 <p> Note: when invoked via "<b>sendmail -bs</b>", Postfix will never offer 13048 STARTTLS due to insufficient privileges to access the server private 13049 key. This is intended behavior. </p> 13050 13051 <p> This feature is available in Postfix 2.2 and later. With 13052 Postfix 2.3 and later use <a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> instead. </p> 13053 13054 13055 </DD> 13056 13057 <DT><b><a name="soft_bounce">soft_bounce</a> 13058 (default: no)</b></DT><DD> 13059 13060 <p> 13061 Safety net to keep mail queued that would otherwise be returned to 13062 the sender. This parameter disables locally-generated bounces, 13063 and prevents the Postfix SMTP server from rejecting mail permanently, 13064 by changing 5xx reply codes into 4xx. However, <a href="postconf.5.html#soft_bounce">soft_bounce</a> is no 13065 cure for address rewriting mistakes or mail routing mistakes. 13066 </p> 13067 13068 <p> 13069 Example: 13070 </p> 13071 13072 <pre> 13073 <a href="postconf.5.html#soft_bounce">soft_bounce</a> = yes 13074 </pre> 13075 13076 13077 </DD> 13078 13079 <DT><b><a name="stale_lock_time">stale_lock_time</a> 13080 (default: 500s)</b></DT><DD> 13081 13082 <p> 13083 The time after which a stale exclusive mailbox lockfile is removed. 13084 This is used for delivery to file or mailbox. 13085 </p> 13086 13087 <p> 13088 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 13089 The default time unit is s (seconds). 13090 </p> 13091 13092 13093 </DD> 13094 13095 <DT><b><a name="stress">stress</a> 13096 (default: empty)</b></DT><DD> 13097 13098 <p> This feature is documented in the <a href="STRESS_README.html">STRESS_README</a> document. </p> 13099 13100 <p> This feature is available in Postfix 2.5 and later. </p> 13101 13102 13103 </DD> 13104 13105 <DT><b><a name="strict_7bit_headers">strict_7bit_headers</a> 13106 (default: no)</b></DT><DD> 13107 13108 <p> 13109 Reject mail with 8-bit text in message headers. This blocks mail 13110 from poorly written applications. 13111 </p> 13112 13113 <p> 13114 This feature should not be enabled on a general purpose mail server, 13115 because it is likely to reject legitimate email. 13116 </p> 13117 13118 <p> 13119 This feature is available in Postfix 2.0 and later. 13120 </p> 13121 13122 13123 </DD> 13124 13125 <DT><b><a name="strict_8bitmime">strict_8bitmime</a> 13126 (default: no)</b></DT><DD> 13127 13128 <p> 13129 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>. 13130 </p> 13131 13132 <p> 13133 This feature should not be enabled on a general purpose mail server, 13134 because it is likely to reject legitimate email. 13135 </p> 13136 13137 <p> 13138 This feature is available in Postfix 2.0 and later. 13139 </p> 13140 13141 13142 </DD> 13143 13144 <DT><b><a name="strict_8bitmime_body">strict_8bitmime_body</a> 13145 (default: no)</b></DT><DD> 13146 13147 <p> 13148 Reject 8-bit message body text without 8-bit MIME content encoding 13149 information. This blocks mail from poorly written applications. 13150 </p> 13151 13152 <p> 13153 Unfortunately, this also rejects majordomo approval requests when 13154 the included request contains valid 8-bit MIME mail, and it rejects 13155 bounces from mailers that do not MIME encapsulate 8-bit content 13156 (for example, bounces from qmail or from old versions of Postfix). 13157 </p> 13158 13159 <p> 13160 This feature should not be enabled on a general purpose mail server, 13161 because it is likely to reject legitimate email. 13162 </p> 13163 13164 <p> 13165 This feature is available in Postfix 2.0 and later. 13166 </p> 13167 13168 13169 </DD> 13170 13171 <DT><b><a name="strict_mailbox_ownership">strict_mailbox_ownership</a> 13172 (default: yes)</b></DT><DD> 13173 13174 <p> Defer delivery when a mailbox file is not owned by its recipient. 13175 The default setting is not backwards compatible. </p> 13176 13177 <p> This feature is available in Postfix 2.5.3 and later. </p> 13178 13179 13180 </DD> 13181 13182 <DT><b><a name="strict_mime_encoding_domain">strict_mime_encoding_domain</a> 13183 (default: no)</b></DT><DD> 13184 13185 <p> 13186 Reject mail with invalid Content-Transfer-Encoding: information 13187 for the message/* or multipart/* MIME content types. This blocks 13188 mail from poorly written software. 13189 </p> 13190 13191 <p> 13192 This feature should not be enabled on a general purpose mail server, 13193 because it will reject mail after a single violation. 13194 </p> 13195 13196 <p> 13197 This feature is available in Postfix 2.0 and later. 13198 </p> 13199 13200 13201 </DD> 13202 13203 <DT><b><a name="strict_rfc821_envelopes">strict_rfc821_envelopes</a> 13204 (default: no)</b></DT><DD> 13205 13206 <p> 13207 Require that addresses received in SMTP MAIL FROM and RCPT TO 13208 commands are enclosed with <>, and that those addresses do 13209 not contain <a href="http://tools.ietf.org/html/rfc822">RFC 822</a> style comments or phrases. This stops mail 13210 from poorly written software. 13211 </p> 13212 13213 <p> 13214 By default, the Postfix SMTP server accepts <a href="http://tools.ietf.org/html/rfc822">RFC 822</a> syntax in MAIL 13215 FROM and RCPT TO addresses. 13216 </p> 13217 13218 13219 </DD> 13220 13221 <DT><b><a name="sun_mailtool_compatibility">sun_mailtool_compatibility</a> 13222 (default: no)</b></DT><DD> 13223 13224 <p> 13225 Obsolete SUN mailtool compatibility feature. Instead, use 13226 "<a href="postconf.5.html#mailbox_delivery_lock">mailbox_delivery_lock</a> = dotlock". 13227 </p> 13228 13229 13230 </DD> 13231 13232 <DT><b><a name="swap_bangpath">swap_bangpath</a> 13233 (default: yes)</b></DT><DD> 13234 13235 <p> 13236 Enable the rewriting of "site!user" into "user@site". This is 13237 necessary if your machine is connected to UUCP networks. It is 13238 enabled by default. 13239 </p> 13240 13241 <p> Note: with Postfix version 2.2, message header address rewriting 13242 happens only when one of the following conditions is true: </p> 13243 13244 <ul> 13245 13246 <li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command, 13247 13248 <li> The message is received from a network client that matches 13249 $<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>, 13250 13251 <li> The message is received from the network, and the 13252 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value. 13253 13254 </ul> 13255 13256 <p> To get the behavior before Postfix version 2.2, specify 13257 "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = static:all". </p> 13258 13259 <p> 13260 Example: 13261 </p> 13262 13263 <pre> 13264 <a href="postconf.5.html#swap_bangpath">swap_bangpath</a> = no 13265 </pre> 13266 13267 13268 </DD> 13269 13270 <DT><b><a name="syslog_facility">syslog_facility</a> 13271 (default: mail)</b></DT><DD> 13272 13273 <p> 13274 The syslog facility of Postfix logging. Specify a facility as 13275 defined in syslog.conf(5). The default facility is "mail". 13276 </p> 13277 13278 <p> 13279 Warning: a non-default <a href="postconf.5.html#syslog_facility">syslog_facility</a> setting takes effect only 13280 after a Postfix process has completed initialization. Errors during 13281 process initialization will be logged with the default facility. 13282 Examples are errors while parsing the command line arguments, and 13283 errors while accessing the Postfix <a href="postconf.5.html">main.cf</a> configuration file. 13284 </p> 13285 13286 13287 </DD> 13288 13289 <DT><b><a name="syslog_name">syslog_name</a> 13290 (default: see "postconf -d" output)</b></DT><DD> 13291 13292 <p> 13293 The mail system name that is prepended to the process name in syslog 13294 records, so that "smtpd" becomes, for example, "postfix/smtpd". 13295 </p> 13296 13297 <p> 13298 Warning: a non-default <a href="postconf.5.html#syslog_name">syslog_name</a> setting takes effect only after 13299 a Postfix process has completed initialization. Errors during 13300 process initialization will be logged with the default name. Examples 13301 are errors while parsing the command line arguments, and errors 13302 while accessing the Postfix <a href="postconf.5.html">main.cf</a> configuration file. 13303 </p> 13304 13305 13306 </DD> 13307 13308 <DT><b><a name="tcp_windowsize">tcp_windowsize</a> 13309 (default: 0)</b></DT><DD> 13310 13311 <p> An optional workaround for routers that break TCP window scaling. 13312 Specify a value > 0 and < 65536 to enable this feature. With 13313 Postfix TCP servers (<a href="smtpd.8.html">smtpd(8)</a>, <a href="qmqpd.8.html">qmqpd(8)</a>), this feature is implemented 13314 by the Postfix <a href="master.8.html">master(8)</a> daemon. </p> 13315 13316 <p> To change this parameter without stopping Postfix, you need to 13317 first terminate all Postfix TCP servers: </p> 13318 13319 <blockquote> 13320 <pre> 13321 # postconf -e <a href="postconf.5.html#master_service_disable">master_service_disable</a>=inet 13322 # postfix reload 13323 </pre> 13324 </blockquote> 13325 13326 <p> This immediately terminates all processes that accept network 13327 connections. Next, you enable Postfix TCP servers with the updated 13328 <a href="postconf.5.html#tcp_windowsize">tcp_windowsize</a> setting: </p> 13329 13330 <blockquote> 13331 <pre> 13332 # 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>= 13333 # postfix reload 13334 </pre> 13335 </blockquote> 13336 13337 <p> If you skip these steps with a running Postfix system, then the 13338 <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>, 13339 <a href="lmtp.8.html">lmtp(8)</a>). </p> 13340 13341 <p> This feature is available in Postfix 2.6 and later. </p> 13342 13343 13344 </DD> 13345 13346 <DT><b><a name="tls_daemon_random_bytes">tls_daemon_random_bytes</a> 13347 (default: 32)</b></DT><DD> 13348 13349 <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> 13350 process requests from the <a href="tlsmgr.8.html">tlsmgr(8)</a> server in order to seed its 13351 internal pseudo random number generator (PRNG). The default of 32 13352 bytes (equivalent to 256 bits) is sufficient to generate a 128bit 13353 (or 168bit) session key. </p> 13354 13355 <p> This feature is available in Postfix 2.2 and later. </p> 13356 13357 13358 </DD> 13359 13360 <DT><b><a name="tls_eecdh_strong_curve">tls_eecdh_strong_curve</a> 13361 (default: prime256v1)</b></DT><DD> 13362 13363 <p> The elliptic curve used by the SMTP server for sensibly strong 13364 ephemeral ECDH key exchange. This curve is used by the Postfix SMTP 13365 server when "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = strong". The phrase "sensibly 13366 strong" means approximately 128-bit security based on best known 13367 attacks. The selected curve must be implemented by OpenSSL (as 13368 reported by ecparam(1) with the "-list_curves" option) and be one 13369 of the curves listed in Section 5.1.1 of <a href="http://tools.ietf.org/html/rfc4492">RFC 4492</a>. You should not 13370 generally change this setting. </p> 13371 13372 <p> This default curve is specified in NSA "Suite B" Cryptography 13373 (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 13374 information classified as SECRET. </p> 13375 13376 <p> Note: elliptic curve names are poorly standardized; different 13377 standards groups are assigning different names to the same underlying 13378 curves. The curve with the X9.62 name "prime256v1" is also known 13379 under the SECG name "secp256r1", but OpenSSL does not recognize the 13380 latter name. </p> 13381 13382 <p> This feature is available in Postfix 2.6 and later, when it is 13383 compiled and linked with OpenSSL 0.9.9 or later. </p> 13384 13385 13386 </DD> 13387 13388 <DT><b><a name="tls_eecdh_ultra_curve">tls_eecdh_ultra_curve</a> 13389 (default: secp384r1)</b></DT><DD> 13390 13391 <p> The elliptic curve used by the SMTP server for maximally strong 13392 ephemeral ECDH key exchange. This curve is used by the Postfix SMTP 13393 server when "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = ultra". The phrase "maximally 13394 strong" means approximately 192-bit security based on best known attacks. 13395 This additional strength comes at a significant computational cost, most 13396 users should instead set "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = strong". The selected 13397 curve must be implemented by OpenSSL (as reported by ecparam(1) with the 13398 "-list_curves" option) and be one of the curves listed in Section 5.1.1 13399 of <a href="http://tools.ietf.org/html/rfc4492">RFC 4492</a>. You should not generally change this setting. </p> 13400 13401 <p> This default "ultra" curve is specified in NSA "Suite B" Cryptography 13402 (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 13403 classified as TOP SECRET. </p> 13404 13405 <p> This feature is available in Postfix 2.6 and later, when it is 13406 compiled and linked with OpenSSL 0.9.9 or later. </p> 13407 13408 13409 </DD> 13410 13411 <DT><b><a name="tls_export_cipherlist">tls_export_cipherlist</a> 13412 (default: ALL:+RC4:@STRENGTH)</b></DT><DD> 13413 13414 <p> The OpenSSL cipherlist for "EXPORT" or higher grade ciphers. This 13415 defines the meaning of the "export" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, 13416 <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 13417 the cipherlist for the opportunistic ("may") TLS client security 13418 level and is the default cipherlist for the SMTP server. You are 13419 strongly encouraged to not change this setting. </p> 13420 13421 <p> This feature is available in Postfix 2.3 and later. </p> 13422 13423 13424 </DD> 13425 13426 <DT><b><a name="tls_high_cipherlist">tls_high_cipherlist</a> 13427 (default: ALL:!EXPORT:!LOW:!MEDIUM:+RC4:@STRENGTH)</b></DT><DD> 13428 13429 <p> The OpenSSL cipherlist for "HIGH" grade ciphers. This defines 13430 the meaning of the "high" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, 13431 <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 13432 strongly encouraged to not change this setting. </p> 13433 13434 <p> This feature is available in Postfix 2.3 and later. </p> 13435 13436 13437 </DD> 13438 13439 <DT><b><a name="tls_low_cipherlist">tls_low_cipherlist</a> 13440 (default: ALL:!EXPORT:+RC4:@STRENGTH)</b></DT><DD> 13441 13442 <p> The OpenSSL cipherlist for "LOW" or higher grade ciphers. This defines 13443 the meaning of the "low" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, 13444 <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 13445 strongly encouraged to not change this setting. </p> 13446 13447 <p> This feature is available in Postfix 2.3 and later. </p> 13448 13449 13450 </DD> 13451 13452 <DT><b><a name="tls_medium_cipherlist">tls_medium_cipherlist</a> 13453 (default: ALL:!EXPORT:!LOW:+RC4:@STRENGTH)</b></DT><DD> 13454 13455 <p> The OpenSSL cipherlist for "MEDIUM" or higher grade ciphers. This 13456 defines the meaning of the "medium" setting in <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, 13457 <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 13458 the default cipherlist for mandatory TLS encryption in the TLS 13459 client (with anonymous ciphers disabled when verifying server 13460 certificates). You are strongly encouraged to not change this 13461 setting. </p> 13462 13463 <p> This feature is available in Postfix 2.3 and later. </p> 13464 13465 13466 </DD> 13467 13468 <DT><b><a name="tls_null_cipherlist">tls_null_cipherlist</a> 13469 (default: eNULL:!aNULL)</b></DT><DD> 13470 13471 <p> The OpenSSL cipherlist for "NULL" grade ciphers that provide 13472 authentication without encryption. This defines the meaning of the "null" 13473 setting in smtpd_mandatory_tls_ciphers, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and 13474 <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are strongly encouraged to not 13475 change this setting. </p> 13476 13477 <p> This feature is available in Postfix 2.3 and later. </p> 13478 13479 13480 </DD> 13481 13482 <DT><b><a name="tls_random_bytes">tls_random_bytes</a> 13483 (default: 32)</b></DT><DD> 13484 13485 <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> 13486 when (re)seeding the in-memory pseudo random number generator (PRNG) 13487 pool. The default of 32 bytes (256 bits) is good enough for 128bit 13488 symmetric keys. If using EGD or a device file, a maximum of 255 13489 bytes is read. </p> 13490 13491 <p> This feature is available in Postfix 2.2 and later. </p> 13492 13493 13494 </DD> 13495 13496 <DT><b><a name="tls_random_exchange_name">tls_random_exchange_name</a> 13497 (default: see "postconf -d" output)</b></DT><DD> 13498 13499 <p> Name of the pseudo random number generator (PRNG) state file 13500 that is maintained by <a href="tlsmgr.8.html">tlsmgr(8)</a>. The file is created when it does 13501 not exist, and its length is fixed at 1024 bytes. </p> 13502 13503 <p> As of version 2.5, Postfix no longer uses root privileges when 13504 opening this file, and the default file location was changed from 13505 ${<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 13506 a migration aid, an attempt to open the file under a non-Postfix 13507 directory is redirected to the Postfix-owned <a href="postconf.5.html#data_directory">data_directory</a>, and a 13508 warning is logged. </p> 13509 13510 <p> This feature is available in Postfix 2.2 and later. </p> 13511 13512 13513 </DD> 13514 13515 <DT><b><a name="tls_random_prng_update_period">tls_random_prng_update_period</a> 13516 (default: 3600s)</b></DT><DD> 13517 13518 <p> The time between attempts by <a href="tlsmgr.8.html">tlsmgr(8)</a> to save the state of 13519 the pseudo random number generator (PRNG) to the file specified 13520 with $<a href="postconf.5.html#tls_random_exchange_name">tls_random_exchange_name</a>. </p> 13521 13522 <p> This feature is available in Postfix 2.2 and later. </p> 13523 13524 13525 </DD> 13526 13527 <DT><b><a name="tls_random_reseed_period">tls_random_reseed_period</a> 13528 (default: 3600s)</b></DT><DD> 13529 13530 <p> The maximal time between attempts by <a href="tlsmgr.8.html">tlsmgr(8)</a> to re-seed the 13531 in-memory pseudo random number generator (PRNG) pool from external 13532 sources. The actual time between re-seeding attempts is calculated 13533 using the PRNG, and is between 0 and the time specified. </p> 13534 13535 <p> This feature is available in Postfix 2.2 and later. </p> 13536 13537 13538 </DD> 13539 13540 <DT><b><a name="tls_random_source">tls_random_source</a> 13541 (default: see "postconf -d" output)</b></DT><DD> 13542 13543 <p> The external entropy source for the in-memory <a href="tlsmgr.8.html">tlsmgr(8)</a> pseudo 13544 random number generator (PRNG) pool. Be sure to specify a non-blocking 13545 source. If this source is not a regular file, the entropy source 13546 type must be prepended: egd:/path/to/egd_socket for a source with 13547 EGD compatible socket interface, or dev:/path/to/device for a 13548 device file. </p> 13549 13550 <p> Note: on OpenBSD systems specify /dev/arandom when /dev/urandom 13551 gives timeout errors. </p> 13552 13553 <p> This feature is available in Postfix 2.2 and later. </p> 13554 13555 13556 </DD> 13557 13558 <DT><b><a name="trace_service_name">trace_service_name</a> 13559 (default: trace)</b></DT><DD> 13560 13561 <p> 13562 The name of the trace service. This service is implemented by the 13563 <a href="bounce.8.html">bounce(8)</a> daemon and maintains a record 13564 of mail deliveries and produces a mail delivery report when verbose 13565 delivery is requested with "<b>sendmail -v</b>". 13566 </p> 13567 13568 <p> 13569 This feature is available in Postfix 2.1 and later. 13570 </p> 13571 13572 13573 </DD> 13574 13575 <DT><b><a name="transport_delivery_slot_cost">transport_delivery_slot_cost</a> 13576 (default: $<a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a>)</b></DT><DD> 13577 13578 <p> A transport-specific override for the <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> 13579 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13580 the message delivery transport. </p> 13581 13582 13583 </DD> 13584 13585 <DT><b><a name="transport_delivery_slot_discount">transport_delivery_slot_discount</a> 13586 (default: $<a href="postconf.5.html#default_delivery_slot_discount">default_delivery_slot_discount</a>)</b></DT><DD> 13587 13588 <p> A transport-specific override for the <a href="postconf.5.html#default_delivery_slot_discount">default_delivery_slot_discount</a> 13589 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13590 the message delivery transport. </p> 13591 13592 13593 </DD> 13594 13595 <DT><b><a name="transport_delivery_slot_loan">transport_delivery_slot_loan</a> 13596 (default: $<a href="postconf.5.html#default_delivery_slot_loan">default_delivery_slot_loan</a>)</b></DT><DD> 13597 13598 <p> A transport-specific override for the <a href="postconf.5.html#default_delivery_slot_loan">default_delivery_slot_loan</a> 13599 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13600 the message delivery transport. </p> 13601 13602 13603 </DD> 13604 13605 <DT><b><a name="transport_destination_concurrency_failed_cohort_limit">transport_destination_concurrency_failed_cohort_limit</a> 13606 (default: $<a href="postconf.5.html#default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a>)</b></DT><DD> 13607 13608 <p> A transport-specific override for the 13609 <a href="postconf.5.html#default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a> parameter value, 13610 where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 13611 transport. </p> 13612 13613 <p> This feature is available in Postfix 2.5 and later. </p> 13614 13615 13616 </DD> 13617 13618 <DT><b><a name="transport_destination_concurrency_limit">transport_destination_concurrency_limit</a> 13619 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 13620 13621 <p> A transport-specific override for the 13622 <a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a> parameter value, where 13623 <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 13624 transport. </p> 13625 13626 13627 </DD> 13628 13629 <DT><b><a name="transport_destination_concurrency_negative_feedback">transport_destination_concurrency_negative_feedback</a> 13630 (default: $<a href="postconf.5.html#default_destination_concurrency_negative_feedback">default_destination_concurrency_negative_feedback</a>)</b></DT><DD> 13631 13632 <p> A transport-specific override for the 13633 <a href="postconf.5.html#default_destination_concurrency_negative_feedback">default_destination_concurrency_negative_feedback</a> parameter value, 13634 where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 13635 transport. </p> 13636 13637 <p> This feature is available in Postfix 2.5 and later. </p> 13638 13639 13640 </DD> 13641 13642 <DT><b><a name="transport_destination_concurrency_positive_feedback">transport_destination_concurrency_positive_feedback</a> 13643 (default: $<a href="postconf.5.html#default_destination_concurrency_positive_feedback">default_destination_concurrency_positive_feedback</a>)</b></DT><DD> 13644 13645 <p> A transport-specific override for the 13646 <a href="postconf.5.html#default_destination_concurrency_positive_feedback">default_destination_concurrency_positive_feedback</a> parameter value, 13647 where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 13648 transport. </p> 13649 13650 <p> This feature is available in Postfix 2.5 and later. </p> 13651 13652 13653 </DD> 13654 13655 <DT><b><a name="transport_destination_rate_delay">transport_destination_rate_delay</a> 13656 (default: $<a href="postconf.5.html#default_destination_rate_delay">default_destination_rate_delay</a>)</b></DT><DD> 13657 13658 <p> A transport-specific override for the <a href="postconf.5.html#default_destination_rate_delay">default_destination_rate_delay</a> 13659 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13660 the message delivery transport. </p> 13661 13662 <p> This feature is available in Postfix 2.5 and later. </p> 13663 13664 13665 </DD> 13666 13667 <DT><b><a name="transport_destination_recipient_limit">transport_destination_recipient_limit</a> 13668 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 13669 13670 <p> A transport-specific override for the 13671 <a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a> parameter value, where 13672 <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery 13673 transport. </p> 13674 13675 13676 </DD> 13677 13678 <DT><b><a name="transport_extra_recipient_limit">transport_extra_recipient_limit</a> 13679 (default: $<a href="postconf.5.html#default_extra_recipient_limit">default_extra_recipient_limit</a>)</b></DT><DD> 13680 13681 <p> A transport-specific override for the <a href="postconf.5.html#default_extra_recipient_limit">default_extra_recipient_limit</a> 13682 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13683 the message delivery transport. </p> 13684 13685 13686 </DD> 13687 13688 <DT><b><a name="transport_initial_destination_concurrency">transport_initial_destination_concurrency</a> 13689 (default: $<a href="postconf.5.html#initial_destination_concurrency">initial_destination_concurrency</a>)</b></DT><DD> 13690 13691 <p> A transport-specific override for the <a href="postconf.5.html#initial_destination_concurrency">initial_destination_concurrency</a> 13692 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13693 the message delivery transport. </p> 13694 13695 <p> This feature is available in Postfix 2.5 and later. </p> 13696 13697 13698 </DD> 13699 13700 <DT><b><a name="transport_maps">transport_maps</a> 13701 (default: empty)</b></DT><DD> 13702 13703 <p> 13704 Optional lookup tables with mappings from recipient address to 13705 (message delivery transport, next-hop destination). See <a href="transport.5.html">transport(5)</a> 13706 for details. 13707 </p> 13708 13709 <p> 13710 Specify zero or more "<a href="DATABASE_README.html">type:table</a>" lookup tables. If you use this 13711 feature with local files, run "<b>postmap /etc/postfix/transport</b>" 13712 after making a change. </p> 13713 13714 <p> For safety reasons, as of Postfix 2.3 this feature does not 13715 allow $number substitutions in regular expression maps. </p> 13716 13717 <p> 13718 Examples: 13719 </p> 13720 13721 <pre> 13722 <a href="postconf.5.html#transport_maps">transport_maps</a> = dbm:/etc/postfix/transport 13723 <a href="postconf.5.html#transport_maps">transport_maps</a> = hash:/etc/postfix/transport 13724 </pre> 13725 13726 13727 </DD> 13728 13729 <DT><b><a name="transport_minimum_delivery_slots">transport_minimum_delivery_slots</a> 13730 (default: $<a href="postconf.5.html#default_minimum_delivery_slots">default_minimum_delivery_slots</a>)</b></DT><DD> 13731 13732 <p> A transport-specific override for the <a href="postconf.5.html#default_minimum_delivery_slots">default_minimum_delivery_slots</a> 13733 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13734 the message delivery transport. </p> 13735 13736 13737 </DD> 13738 13739 <DT><b><a name="transport_recipient_limit">transport_recipient_limit</a> 13740 (default: $<a href="postconf.5.html#default_recipient_limit">default_recipient_limit</a>)</b></DT><DD> 13741 13742 <p> A transport-specific override for the <a href="postconf.5.html#default_recipient_limit">default_recipient_limit</a> 13743 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13744 the message delivery transport. </p> 13745 13746 13747 </DD> 13748 13749 <DT><b><a name="transport_recipient_refill_delay">transport_recipient_refill_delay</a> 13750 (default: $<a href="postconf.5.html#default_recipient_refill_delay">default_recipient_refill_delay</a>)</b></DT><DD> 13751 13752 <p> A transport-specific override for the <a href="postconf.5.html#default_recipient_refill_delay">default_recipient_refill_delay</a> 13753 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13754 the message delivery transport. </p> 13755 13756 <p> This feature is available in Postfix 2.4 and later. </p> 13757 13758 13759 </DD> 13760 13761 <DT><b><a name="transport_recipient_refill_limit">transport_recipient_refill_limit</a> 13762 (default: $<a href="postconf.5.html#default_recipient_refill_limit">default_recipient_refill_limit</a>)</b></DT><DD> 13763 13764 <p> A transport-specific override for the <a href="postconf.5.html#default_recipient_refill_limit">default_recipient_refill_limit</a> 13765 parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of 13766 the message delivery transport. </p> 13767 13768 <p> This feature is available in Postfix 2.4 and later. </p> 13769 13770 13771 </DD> 13772 13773 <DT><b><a name="transport_retry_time">transport_retry_time</a> 13774 (default: 60s)</b></DT><DD> 13775 13776 <p> 13777 The time between attempts by the Postfix queue manager to contact 13778 a malfunctioning message delivery transport. 13779 </p> 13780 13781 <p> 13782 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 13783 The default time unit is s (seconds). 13784 </p> 13785 13786 13787 </DD> 13788 13789 <DT><b><a name="transport_time_limit">transport_time_limit</a> 13790 (default: $<a href="postconf.5.html#command_time_limit">command_time_limit</a>)</b></DT><DD> 13791 13792 <p> A transport-specific override for the <a href="postconf.5.html#command_time_limit">command_time_limit</a> parameter 13793 value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message 13794 delivery transport. </p> 13795 13796 13797 </DD> 13798 13799 <DT><b><a name="trigger_timeout">trigger_timeout</a> 13800 (default: 10s)</b></DT><DD> 13801 13802 <p> 13803 The time limit for sending a trigger to a Postfix daemon (for 13804 example, the <a href="pickup.8.html">pickup(8)</a> or <a href="qmgr.8.html">qmgr(8)</a> daemon). This time limit prevents 13805 programs from getting stuck when the mail system is under heavy 13806 load. 13807 </p> 13808 13809 <p> 13810 Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). 13811 The default time unit is s (seconds). 13812 </p> 13813 13814 13815 </DD> 13816 13817 <DT><b><a name="undisclosed_recipients_header">undisclosed_recipients_header</a> 13818 (default: To: undisclosed-recipients:;)</b></DT><DD> 13819 13820 <p> 13821 Message header that the Postfix <a href="cleanup.8.html">cleanup(8)</a> server inserts when a 13822 message contains no To: or Cc: message header. With Postfix 2.4 13823 and later, specify an empty value to disable this feature. </p> 13824 13825 13826 </DD> 13827 13828 <DT><b><a name="unknown_address_reject_code">unknown_address_reject_code</a> 13829 (default: 450)</b></DT><DD> 13830 13831 <p> 13832 The numerical Postfix SMTP server response code when a sender or 13833 recipient address is rejected by the <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a> 13834 or <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a> restriction. The response is 13835 always 450 in case of a temporary DNS error. 13836 </p> 13837 13838 <p> 13839 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 13840 </p> 13841 13842 13843 </DD> 13844 13845 <DT><b><a name="unknown_address_tempfail_action">unknown_address_tempfail_action</a> 13846 (default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD> 13847 13848 <p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a> 13849 or <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a> fail due to a temporary error 13850 condition. Specify "defer" to defer the remote SMTP client request 13851 immediately. With the default "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix 13852 SMTP server continues to look for opportunities to reject mail, and 13853 defers the client request only if it would otherwise be accepted. 13854 </p> 13855 13856 <p> This feature is available in Postfix 2.6 and later. </p> 13857 13858 13859 </DD> 13860 13861 <DT><b><a name="unknown_client_reject_code">unknown_client_reject_code</a> 13862 (default: 450)</b></DT><DD> 13863 13864 <p> 13865 The numerical Postfix SMTP server response code when a client 13866 without valid address <=> name mapping is rejected by the 13867 <a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> restriction. The SMTP server always replies 13868 with 450 when the mapping failed due to a temporary error condition. 13869 </p> 13870 13871 <p> 13872 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 13873 </p> 13874 13875 13876 </DD> 13877 13878 <DT><b><a name="unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a> 13879 (default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD> 13880 13881 <p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> 13882 fails due to an temporary error condition. Specify "defer" to defer 13883 the remote SMTP client request immediately. With the default 13884 "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look 13885 for opportunities to reject mail, and defers the client request 13886 only if it would otherwise be accepted. </p> 13887 13888 <p> This feature is available in Postfix 2.6 and later. </p> 13889 13890 13891 </DD> 13892 13893 <DT><b><a name="unknown_hostname_reject_code">unknown_hostname_reject_code</a> 13894 (default: 450)</b></DT><DD> 13895 13896 <p> 13897 The numerical Postfix SMTP server response code when the hostname 13898 specified with the HELO or EHLO command is rejected by the 13899 <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> restriction. 13900 </p> 13901 13902 <p> 13903 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 13904 </p> 13905 13906 13907 </DD> 13908 13909 <DT><b><a name="unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> 13910 (default: 550)</b></DT><DD> 13911 13912 <p> 13913 The numerical Postfix SMTP server response code when a recipient 13914 address is local, and $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> specifies a list of 13915 lookup tables that does not match the recipient. A recipient 13916 address is local when its domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, 13917 $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> or $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>. 13918 </p> 13919 13920 <p> 13921 The default setting is 550 (reject mail) but it is safer to initially 13922 use 450 (try again later) so you have time to find out if your 13923 <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> settings are OK. 13924 </p> 13925 13926 <p> 13927 Example: 13928 </p> 13929 13930 <pre> 13931 <a href="postconf.5.html#unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> = 450 13932 </pre> 13933 13934 <p> 13935 This feature is available in Postfix 2.0 and later. 13936 </p> 13937 13938 13939 </DD> 13940 13941 <DT><b><a name="unknown_relay_recipient_reject_code">unknown_relay_recipient_reject_code</a> 13942 (default: 550)</b></DT><DD> 13943 13944 <p> 13945 The numerical Postfix SMTP server reply code when a recipient 13946 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 13947 a list of lookup tables that does not match the recipient address. 13948 </p> 13949 13950 <p> 13951 This feature is available in Postfix 2.0 and later. 13952 </p> 13953 13954 13955 </DD> 13956 13957 <DT><b><a name="unknown_virtual_alias_reject_code">unknown_virtual_alias_reject_code</a> 13958 (default: 550)</b></DT><DD> 13959 13960 <p> 13961 The SMTP server reply code when a recipient address matches 13962 $<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 13963 of lookup tables that does not match the recipient address. 13964 </p> 13965 13966 <p> 13967 This feature is available in Postfix 2.0 and later. 13968 </p> 13969 13970 13971 </DD> 13972 13973 <DT><b><a name="unknown_virtual_mailbox_reject_code">unknown_virtual_mailbox_reject_code</a> 13974 (default: 550)</b></DT><DD> 13975 13976 <p> 13977 The SMTP server reply code when a recipient address matches 13978 $<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 13979 of lookup tables that does not match the recipient address. 13980 </p> 13981 13982 <p> 13983 This feature is available in Postfix 2.0 and later. 13984 </p> 13985 13986 13987 </DD> 13988 13989 <DT><b><a name="unverified_recipient_defer_code">unverified_recipient_defer_code</a> 13990 (default: 450)</b></DT><DD> 13991 13992 <p> 13993 The numerical Postfix SMTP server response when a recipient address 13994 probe fails due to a temporary error condition. 13995 </p> 13996 13997 <p> 13998 Unlike elsewhere in Postfix, you can specify 250 in order to 13999 accept the address anyway. 14000 </p> 14001 14002 <p> 14003 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 14004 </p> 14005 14006 <p> 14007 This feature is available in Postfix 2.6 and later. 14008 </p> 14009 14010 14011 </DD> 14012 14013 <DT><b><a name="unverified_recipient_reject_code">unverified_recipient_reject_code</a> 14014 (default: 450)</b></DT><DD> 14015 14016 <p> 14017 The numerical Postfix SMTP server response when a recipient address 14018 is rejected by the <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> restriction. 14019 </p> 14020 14021 <p> 14022 Unlike elsewhere in Postfix, you can specify 250 in order to 14023 accept the address anyway. 14024 </p> 14025 14026 <p> 14027 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 14028 </p> 14029 14030 <p> 14031 This feature is available in Postfix 2.1 and later. 14032 </p> 14033 14034 14035 </DD> 14036 14037 <DT><b><a name="unverified_recipient_reject_reason">unverified_recipient_reject_reason</a> 14038 (default: empty)</b></DT><DD> 14039 14040 <p> The Postfix SMTP server's reply when rejecting mail with 14041 <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>. Do not include the numeric SMTP reply 14042 code or the enhanced status code. By default, the response includes 14043 actual address verification details. 14044 14045 <p> Example: </p> 14046 14047 <pre> 14048 <a href="postconf.5.html#unverified_recipient_reject_reason">unverified_recipient_reject_reason</a> = Recipient address lookup failed 14049 </pre> 14050 14051 <p> This feature is available in Postfix 2.6 and later. </p> 14052 14053 14054 </DD> 14055 14056 <DT><b><a name="unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a> 14057 (default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD> 14058 14059 <p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> 14060 fails due to a temporary error condition. Specify "defer" to defer 14061 the remote SMTP client request immediately. With the default 14062 "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look 14063 for opportunities to reject mail, and defers the client request 14064 only if it would otherwise be accepted. </p> 14065 14066 <p> This feature is available in Postfix 2.6 and later. </p> 14067 14068 14069 </DD> 14070 14071 <DT><b><a name="unverified_sender_defer_code">unverified_sender_defer_code</a> 14072 (default: 450)</b></DT><DD> 14073 14074 <p> 14075 The numerical Postfix SMTP server response code when a sender address 14076 probe fails due to a temporary error condition. 14077 </p> 14078 14079 <p> 14080 Unlike elsewhere in Postfix, you can specify 250 in order to 14081 accept the address anyway. 14082 </p> 14083 14084 <p> 14085 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 14086 </p> 14087 14088 <p> 14089 This feature is available in Postfix 2.6 and later. 14090 </p> 14091 14092 14093 </DD> 14094 14095 <DT><b><a name="unverified_sender_reject_code">unverified_sender_reject_code</a> 14096 (default: 450)</b></DT><DD> 14097 14098 <p> 14099 The numerical Postfix SMTP server response code when a recipient 14100 address is rejected by the <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> restriction. 14101 </p> 14102 14103 <p> 14104 Unlike elsewhere in Postfix, you can specify 250 in order to 14105 accept the address anyway. 14106 </p> 14107 14108 <p> 14109 Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. 14110 </p> 14111 14112 <p> 14113 This feature is available in Postfix 2.1 and later. 14114 </p> 14115 14116 14117 </DD> 14118 14119 <DT><b><a name="unverified_sender_reject_reason">unverified_sender_reject_reason</a> 14120 (default: empty)</b></DT><DD> 14121 14122 <p> The Postfix SMTP server's reply when rejecting mail with 14123 <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a>. Do not include the numeric SMTP reply 14124 code or the enhanced status code. By default, the response includes 14125 actual address verification details. 14126 14127 <p> Example: </p> 14128 14129 <pre> 14130 <a href="postconf.5.html#unverified_sender_reject_reason">unverified_sender_reject_reason</a> = Sender address lookup failed 14131 </pre> 14132 14133 <p> This feature is available in Postfix 2.6 and later. </p> 14134 14135 14136 </DD> 14137 14138 <DT><b><a name="unverified_sender_tempfail_action">unverified_sender_tempfail_action</a> 14139 (default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD> 14140 14141 <p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> 14142 fails due to a temporary error condition. Specify "defer" to defer 14143 the remote SMTP client request immediately. With the default 14144 "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look 14145 for opportunities to reject mail, and defers the client request 14146 only if it would otherwise be accepted. </p> 14147 14148 <p> This feature is available in Postfix 2.6 and later. </p> 14149 14150 14151 </DD> 14152 14153 <DT><b><a name="verp_delimiter_filter">verp_delimiter_filter</a> 14154 (default: -=+)</b></DT><DD> 14155 14156 <p> 14157 The characters Postfix accepts as VERP delimiter characters on the 14158 Postfix <a href="sendmail.1.html">sendmail(1)</a> command line and in SMTP commands. 14159 </p> 14160 14161 <p> 14162 This feature is available in Postfix 1.1 and later. 14163 </p> 14164 14165 14166 </DD> 14167 14168 <DT><b><a name="virtual_alias_domains">virtual_alias_domains</a> 14169 (default: $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>)</b></DT><DD> 14170 14171 <p> Postfix is final destination for the specified list of virtual 14172 alias domains, that is, domains for which all addresses are aliased 14173 to addresses in other local or remote domains. The SMTP server 14174 validates recipient addresses with $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> and rejects 14175 non-existent recipients. See also the <a href="ADDRESS_CLASS_README.html#virtual_alias_class">virtual alias domain</a> class 14176 in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file </p> 14177 14178 <p> 14179 This feature is available in Postfix 2.0 and later. The default 14180 value is backwards compatible with Postfix version 1.1. 14181 </p> 14182 14183 <p> 14184 The default value is $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> so that you can keep all 14185 information about <a href="ADDRESS_CLASS_README.html#virtual_alias_class">virtual alias domains</a> in one place. If you have 14186 many users, it is better to separate information that changes more 14187 frequently (virtual address -> local or remote address mapping) 14188 from information that changes less frequently (the list of virtual 14189 domain names). 14190 </p> 14191 14192 <p> Specify a list of host or domain names, "/file/name" or 14193 "<a href="DATABASE_README.html">type:table</a>" patterns, separated by commas and/or whitespace. A 14194 "/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" 14195 lookup table is matched when a table entry matches a lookup string 14196 (the lookup result is ignored). Continue long lines by starting 14197 the next line with whitespace. Specify "!pattern" to exclude a host 14198 or domain name from the list. The form "!/file/name" is supported 14199 only in Postfix version 2.4 and later. </p> 14200 14201 <p> 14202 See also the <a href="VIRTUAL_README.html">VIRTUAL_README</a> and <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> documents 14203 for further information. 14204 </p> 14205 14206 <p> 14207 Example: 14208 </p> 14209 14210 <pre> 14211 <a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> = virtual1.tld virtual2.tld 14212 </pre> 14213 14214 14215 </DD> 14216 14217 <DT><b><a name="virtual_alias_expansion_limit">virtual_alias_expansion_limit</a> 14218 (default: 1000)</b></DT><DD> 14219 14220 <p> 14221 The maximal number of addresses that virtual alias expansion produces 14222 from each original recipient. 14223 </p> 14224 14225 <p> 14226 This feature is available in Postfix 2.1 and later. 14227 </p> 14228 14229 14230 </DD> 14231 14232 <DT><b><a name="virtual_alias_maps">virtual_alias_maps</a> 14233 (default: $<a href="postconf.5.html#virtual_maps">virtual_maps</a>)</b></DT><DD> 14234 14235 <p> 14236 Optional lookup tables that alias specific mail addresses or domains 14237 to other local or remote address. The table format and lookups 14238 are documented in <a href="virtual.5.html">virtual(5)</a>. For an overview of Postfix address 14239 manipulations see the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> document. 14240 </p> 14241 14242 <p> 14243 This feature is available in Postfix 2.0 and later. The default 14244 value is backwards compatible with Postfix version 1.1. 14245 </p> 14246 14247 <p> 14248 If you use this feature with indexed files, run "<b>postmap 14249 /etc/postfix/virtual</b>" after changing the file. 14250 </p> 14251 14252 <p> 14253 Examples: 14254 </p> 14255 14256 <pre> 14257 <a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> = dbm:/etc/postfix/virtual 14258 <a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> = hash:/etc/postfix/virtual 14259 </pre> 14260 14261 14262 </DD> 14263 14264 <DT><b><a name="virtual_alias_recursion_limit">virtual_alias_recursion_limit</a> 14265 (default: 1000)</b></DT><DD> 14266 14267 <p> 14268 The maximal nesting depth of virtual alias expansion. Currently 14269 the recursion limit is applied only to the left branch of the 14270 expansion graph, so the depth of the tree can in the worst case 14271 reach the sum of the expansion and recursion limits. This may 14272 change in the future. 14273 </p> 14274 14275 <p> 14276 This feature is available in Postfix 2.1 and later. 14277 </p> 14278 14279 14280 </DD> 14281 14282 <DT><b><a name="virtual_destination_concurrency_limit">virtual_destination_concurrency_limit</a> 14283 (default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD> 14284 14285 <p> The maximal number of parallel deliveries to the same destination 14286 via the virtual message delivery transport. This limit is enforced 14287 by the queue manager. The message delivery transport name is the 14288 first field in the entry in the <a href="master.5.html">master.cf</a> file. </p> 14289 14290 14291 </DD> 14292 14293 <DT><b><a name="virtual_destination_recipient_limit">virtual_destination_recipient_limit</a> 14294 (default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD> 14295 14296 <p> The maximal number of recipients per message for the virtual 14297 message delivery transport. This limit is enforced by the queue 14298 manager. The message delivery transport name is the first field in 14299 the entry in the <a href="master.5.html">master.cf</a> file. </p> 14300 14301 <p> Setting this parameter to a value of 1 changes the meaning of 14302 <a href="postconf.5.html#virtual_destination_concurrency_limit">virtual_destination_concurrency_limit</a> from concurrency per domain 14303 into concurrency per recipient. </p> 14304 14305 14306 </DD> 14307 14308 <DT><b><a name="virtual_gid_maps">virtual_gid_maps</a> 14309 (default: empty)</b></DT><DD> 14310 14311 <p> 14312 Lookup tables with the per-recipient group ID for <a href="virtual.8.html">virtual(8)</a> mailbox 14313 delivery. 14314 </p> 14315 14316 <p> 14317 In a lookup table, specify a left-hand side of "@domain.tld" to 14318 match any user in the specified domain that does not have a specific 14319 "user (a] domain.tld" entry. 14320 </p> 14321 14322 <p> 14323 When a recipient address has an optional address extension 14324 (user+foo (a] domain.tld), the <a href="virtual.8.html">virtual(8)</a> delivery agent looks up 14325 the full address first, and when the lookup fails, it looks up the 14326 unextended address (user (a] domain.tld). 14327 </p> 14328 14329 <p> 14330 Note 1: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent disallows 14331 regular expression substitution of $1 etc. in regular expression 14332 lookup tables, because that would open a security hole. 14333 </p> 14334 14335 <p> 14336 Note 2: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent will 14337 silently ignore requests to use the <a href="proxymap.8.html">proxymap(8)</a> server. Instead 14338 it will open the table directly. Before Postfix version 2.2, the 14339 <a href="virtual.8.html">virtual(8)</a> delivery agent will terminate with a fatal error. 14340 </p> 14341 14342 14343 </DD> 14344 14345 <DT><b><a name="virtual_mailbox_base">virtual_mailbox_base</a> 14346 (default: empty)</b></DT><DD> 14347 14348 <p> 14349 A prefix that the <a href="virtual.8.html">virtual(8)</a> delivery agent prepends to all pathname 14350 results from $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> table lookups. This is a safety 14351 measure to ensure that an out of control map doesn't litter the 14352 file system with mailboxes. While <a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> could be 14353 set to "/", this setting isn't recommended. 14354 </p> 14355 14356 <p> 14357 Example: 14358 </p> 14359 14360 <pre> 14361 <a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> = /var/mail 14362 </pre> 14363 14364 14365 </DD> 14366 14367 <DT><b><a name="virtual_mailbox_domains">virtual_mailbox_domains</a> 14368 (default: $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>)</b></DT><DD> 14369 14370 <p> Postfix is final destination for the specified list of domains; 14371 mail is delivered via the $<a href="postconf.5.html#virtual_transport">virtual_transport</a> mail delivery transport. 14372 By default this is the Postfix <a href="virtual.8.html">virtual(8)</a> delivery agent. The SMTP 14373 server validates recipient addresses with $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> 14374 and rejects mail for non-existent recipients. See also the virtual 14375 mailbox domain class in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file. </p> 14376 14377 <p> This parameter expects the same syntax as the <a href="postconf.5.html#mydestination">mydestination</a> 14378 configuration parameter. </p> 14379 14380 <p> 14381 This feature is available in Postfix 2.0 and later. The default 14382 value is backwards compatible with Postfix version 1.1. 14383 </p> 14384 14385 14386 </DD> 14387 14388 <DT><b><a name="virtual_mailbox_limit">virtual_mailbox_limit</a> 14389 (default: 51200000)</b></DT><DD> 14390 14391 <p> 14392 The maximal size in bytes of an individual mailbox or maildir file, 14393 or zero (no limit). 14394 </p> 14395 14396 14397 </DD> 14398 14399 <DT><b><a name="virtual_mailbox_lock">virtual_mailbox_lock</a> 14400 (default: see "postconf -d" output)</b></DT><DD> 14401 14402 <p> 14403 How to lock a UNIX-style <a href="virtual.8.html">virtual(8)</a> mailbox before attempting 14404 delivery. For a list of available file locking methods, use the 14405 "<b>postconf -l</b>" command. 14406 </p> 14407 14408 <p> 14409 This setting is ignored with <b>maildir</b> style delivery, because 14410 such deliveries are safe without application-level locks. 14411 </p> 14412 14413 <p> 14414 Note 1: the <b>dotlock</b> method requires that the recipient UID 14415 or GID has write access to the parent directory of the recipient's 14416 mailbox file. 14417 </p> 14418 14419 <p> 14420 Note 2: the default setting of this parameter is system dependent. 14421 </p> 14422 14423 14424 </DD> 14425 14426 <DT><b><a name="virtual_mailbox_maps">virtual_mailbox_maps</a> 14427 (default: empty)</b></DT><DD> 14428 14429 <p> 14430 Optional lookup tables with all valid addresses in the domains that 14431 match $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. 14432 </p> 14433 14434 <p> 14435 In a lookup table, specify a left-hand side of "@domain.tld" to 14436 match any user in the specified domain that does not have a specific 14437 "user (a] domain.tld" entry. 14438 </p> 14439 14440 <p> 14441 The <a href="virtual.8.html">virtual(8)</a> delivery agent uses this table to look up the 14442 per-recipient mailbox or maildir pathname. If the lookup result 14443 ends in a slash ("/"), maildir-style delivery is carried out, 14444 otherwise the path is assumed to specify a UNIX-style mailbox file. 14445 Note that $<a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> is unconditionally prepended to 14446 this path. 14447 </p> 14448 14449 <p> 14450 When a recipient address has an optional address extension 14451 (user+foo (a] domain.tld), the <a href="virtual.8.html">virtual(8)</a> delivery agent looks up 14452 the full address first, and when the lookup fails, it looks up the 14453 unextended address (user (a] domain.tld). 14454 </p> 14455 14456 <p> 14457 Note 1: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent disallows 14458 regular expression substitution of $1 etc. in regular expression 14459 lookup tables, because that would open a security hole. 14460 </p> 14461 14462 <p> 14463 Note 2: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent will 14464 silently ignore requests to use the <a href="proxymap.8.html">proxymap(8)</a> server. Instead 14465 it will open the table directly. Before Postfix version 2.2, the 14466 <a href="virtual.8.html">virtual(8)</a> delivery agent will terminate with a fatal error. 14467 </p> 14468 14469 14470 </DD> 14471 14472 <DT><b><a name="virtual_maps">virtual_maps</a> 14473 (default: empty)</b></DT><DD> 14474 14475 <p> Optional lookup tables with a) names of domains for which all 14476 addresses are aliased to addresses in other local or remote domains, 14477 and b) addresses that are aliased to addresses in other local or 14478 remote domains. Available before Postfix version 2.0. With Postfix 14479 version 2.0 and later, this is replaced by separate controls: <a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> 14480 and <a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>. </p> 14481 14482 14483 </DD> 14484 14485 <DT><b><a name="virtual_minimum_uid">virtual_minimum_uid</a> 14486 (default: 100)</b></DT><DD> 14487 14488 <p> 14489 The minimum user ID value that the <a href="virtual.8.html">virtual(8)</a> delivery agent accepts 14490 as a result from $<a href="postconf.5.html#virtual_uid_maps">virtual_uid_maps</a> table lookup. Returned 14491 values less than this will be rejected, and the message will be 14492 deferred. 14493 </p> 14494 14495 14496 </DD> 14497 14498 <DT><b><a name="virtual_transport">virtual_transport</a> 14499 (default: virtual)</b></DT><DD> 14500 14501 <p> 14502 The default mail delivery transport and next-hop destination for 14503 final delivery to domains listed with $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. 14504 This information can be overruled with the <a href="transport.5.html">transport(5)</a> table. 14505 </p> 14506 14507 <p> 14508 Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i> 14509 is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>. 14510 The <i>:nexthop</i> part is optional. For more details see the 14511 <a href="transport.5.html">transport(5)</a> manual page. 14512 </p> 14513 14514 <p> 14515 This feature is available in Postfix 2.0 and later. 14516 </p> 14517 14518 14519 </DD> 14520 14521 <DT><b><a name="virtual_uid_maps">virtual_uid_maps</a> 14522 (default: empty)</b></DT><DD> 14523 14524 <p> 14525 Lookup tables with the per-recipient user ID that the <a href="virtual.8.html">virtual(8)</a> 14526 delivery agent uses while writing to the recipient's mailbox. 14527 </p> 14528 14529 <p> 14530 In a lookup table, specify a left-hand side of "@domain.tld" 14531 to match any user in the specified domain that does not have a 14532 specific "user (a] domain.tld" entry. 14533 </p> 14534 14535 <p> 14536 When a recipient address has an optional address extension 14537 (user+foo (a] domain.tld), the <a href="virtual.8.html">virtual(8)</a> delivery agent looks up 14538 the full address first, and when the lookup fails, it looks up the 14539 unextended address (user (a] domain.tld). 14540 </p> 14541 14542 <p> 14543 Note 1: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent disallows 14544 regular expression substitution of $1 etc. in regular expression 14545 lookup tables, because that would open a security hole. 14546 </p> 14547 14548 <p> 14549 Note 2: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent will 14550 silently ignore requests to use the <a href="proxymap.8.html">proxymap(8)</a> server. Instead 14551 it will open the table directly. Before Postfix version 2.2, the 14552 <a href="virtual.8.html">virtual(8)</a> delivery agent will terminate with a fatal error. 14553 </p> 14554 14555 14556 </DD> 14557 14558 </dl> 14559 14560 </body> 14561 14562 </html> 14563
Indexes created Fri Sep 25 00:27:33 UTC 2026