xref: /src/external/ibm-public/postfix/dist/proto/aliases

#++
# NAME
#	aliases 5
# SUMMARY
#	Postfix local alias database format
# SYNOPSIS
# .fi
#	\fBnewaliases\fR
# DESCRIPTION
#	The \fBaliases\fR(5) table provides a system-wide mechanism to
#	redirect mail for local recipients. The redirections are
#	processed by the Postfix \fBlocal\fR(8) delivery agent.
#
#	Normally, the \fBaliases\fR(5) table is specified as a text file
#	that serves as input to the \fBpostalias\fR(1) command. The
#	result, an indexed file in \fBdbm\fR or \fBdb\fR format, is
#	used for fast lookup by the mail system. Execute the command
#	\fBnewaliases\fR in order to rebuild the indexed file after
#	changing the Postfix alias database.
#
#	When the table is provided via other means such as NIS, LDAP
#	or SQL, the same lookups are done as for ordinary indexed files.
#
#	Alternatively, the table can be provided as a regular-expression
#	map where patterns are given as regular expressions. In
#	this case, the lookups are done in a slightly different way
#	as described below under "REGULAR EXPRESSION TABLES".
#
#	Users can control delivery of their own mail by setting
#	up \fB.forward\fR files in their home directory.
#	Lines in per-user \fB.forward\fR files have the same syntax
#	as the right-hand side of \fBaliases\fR(5) entries.
#
#	The format of the alias database input file is as follows:
# .IP \(bu
#	An alias definition has the form
# .sp
# .nf
#	     \fIname\fR: \fIvalue1\fR, \fIvalue2\fR, \fI...\fR
# .fi
# .IP \(bu
#	Empty lines and whitespace-only lines are ignored, as
#	are lines whose first non-whitespace character is a `#'.
# .IP \(bu
#	A logical line starts with non-whitespace text. A line that
#	starts with whitespace continues a logical line.
# .PP
#	The \fIname\fR is a local address (no domain part).
#	Use double quotes when the name contains any special characters
#	such as whitespace, `#', `:', or `@'. The \fIname\fR is folded to
#	lowercase, in order to make database lookups case insensitive.
# .PP
#	In addition, when an alias exists for \fBowner-\fIname\fR,
#	this will override the envelope sender address, so that
#	delivery diagnostics are directed to \fBowner-\fIname\fR,
#	instead of the originator of the message (for details, see
#	\fBowner_request_special\fR, \fBexpand_owner_alias\fR and
#	\fBreset_owner_alias\fR).
#	This is typically used to direct delivery errors to the maintainer of
#	a mailing list, who is in a better position to deal with mailing
#	list delivery problems than the originator of the undelivered mail.
# .PP
#	The \fIvalue\fR contains one or more of the following:
# .IP \fIaddress\fR
#	Mail is forwarded to \fIaddress\fR, which is compatible
#	with the RFC 822 standard.
# .IP \fI/file/name\fR
#	Mail is appended to \fI/file/name\fR. See \fBlocal\fR(8)
#	for details of delivery to file.
#	Delivery is not limited to regular files.  For example, to dispose
#	of unwanted mail, deflect it to \fB/dev/null\fR.
# .IP "|\fIcommand\fR"
#	Mail is piped into \fIcommand\fR. Commands that contain special
#	characters, such as whitespace, should be enclosed between double
#	quotes. See \fBlocal\fR(8) for details of delivery to command.
# .sp
#	When the command fails, a limited amount of command output is
#	mailed back to the sender.  The file \fB/usr/include/sysexits.h\fR
#	defines the expected exit status codes. For example, use
#	\fB"|exit 67"\fR to simulate a "user unknown" error, and
#	\fB"|exit 0"\fR to implement an expensive black hole.
# .IP \fB:include:\fI/file/name\fR
#	Mail is sent to the destinations listed in the named file.
#	Lines in \fB:include:\fR files have the same syntax
#	as the right-hand side of alias entries.
# .sp
#	A destination can be any destination that is described in this
#	manual page. However, delivery to "|\fIcommand\fR" and
#	\fI/file/name\fR is disallowed by default. To enable, edit the
#	\fBallow_mail_to_commands\fR and \fBallow_mail_to_files\fR
#	configuration parameters.
# ADDRESS EXTENSION
# .ad
# .fi
#	When alias database search fails, and the recipient localpart
#	contains the optional recipient delimiter (e.g., \fIuser+foo\fR),
#	the search is repeated for the unextended address (e.g., \fIuser\fR).
#
#	The \fBpropagate_unmatched_extensions\fR parameter controls
#	whether an unmatched address extension (\fI+foo\fR) is
#	propagated to the result of table lookup.
# CASE FOLDING
# .ad
# .fi
#	The local(8) delivery agent always folds the search string
#	to lowercase before database lookup.
# REGULAR EXPRESSION TABLES
# .ad
# .fi
#	This section describes how the table lookups change when the table
#	is given in the form of regular expressions. For a description of
#	regular expression lookup table syntax, see \fBregexp_table\fR(5)
#	or \fBpcre_table\fR(5). NOTE: these formats do not use ":" at the
#	end of a pattern.
#
#	Each regular expression is applied to the entire search
#	string. Thus, a search string \fIuser+foo\fR is not broken
#	up into \fIuser\fR and \fIfoo\fR.
#
#	Regular expressions are applied in the order as specified
#	in the table, until a regular expression is found that
#	matches the search string.
#
#	Lookup results are the same as with indexed file lookups.
#	For security reasons there is no support for \fB$1\fR,
#	\fB$2\fR etc. substring interpolation.
# SECURITY
# .ad
# .fi
#	The \fBlocal\fR(8) delivery agent disallows regular expression
#	substitution of $1 etc. in \fBalias_maps\fR, because that
#	would open a security hole.
#
#	The \fBlocal\fR(8) delivery agent will silently ignore
#	requests to use the \fBproxymap\fR(8) server within
#	\fBalias_maps\fR. Instead it will open the table directly.
#	Before Postfix version 2.2, the \fBlocal\fR(8) delivery
#	agent will terminate with a fatal error.
# CONFIGURATION PARAMETERS
# .ad
# .fi
#	The following \fBmain.cf\fR parameters are especially relevant.
#	The text below provides only a parameter summary. See
#	\fBpostconf\fR(5) for more details including examples.
# .IP "\fBalias_database (see 'postconf -d' output)\fR"
#	The alias databases for \fBlocal\fR(8) delivery that are updated with
#	"\fBnewaliases\fR" or with "\fBsendmail -bi\fR".
# .IP "\fBalias_maps (see 'postconf -d' output)\fR"
#	The alias databases that are used for \fBlocal\fR(8) delivery.
# .IP "\fBallow_mail_to_commands (alias, forward)\fR"
#	Restrict \fBlocal\fR(8) mail delivery to external commands.
# .IP "\fBallow_mail_to_files (alias, forward)\fR"
#	Restrict \fBlocal\fR(8) mail delivery to external files.
# .IP "\fBexpand_owner_alias (no)\fR"
#	When delivering to an alias "\fIaliasname\fR" that has an
#	"owner-\fIaliasname\fR" companion alias, set the envelope sender
#	address to the expansion of the "owner-\fIaliasname\fR" alias.
# .IP "\fBpropagate_unmatched_extensions (canonical, virtual)\fR"
#	What address lookup tables copy an address extension from the lookup
#	key to the lookup result.
# .IP "\fBowner_request_special (yes)\fR"
#	Enable special treatment for owner-\fIlistname\fR entries in the
#	\fBaliases\fR(5) file, and don't split owner-\fIlistname\fR and
#	\fIlistname\fR-request address localparts when the recipient_delimiter
#	is set to "-".
# .IP "\fBrecipient_delimiter (empty)\fR"
#	The set of characters that can separate an email address
#	localpart, user name, or a .forward file name from its extension.
# .PP
#	Available in Postfix version 2.3 and later:
# .IP "\fBfrozen_delivered_to (yes)\fR"
#	Update the \fBlocal\fR(8) delivery agent's idea of the Delivered-To:
#	address (see prepend_delivered_header) only once, at the start of
#	a delivery attempt; do not update the Delivered-To: address while
#	expanding aliases or .forward files.
# STANDARDS
#	RFC 822 (ARPA Internet Text Messages)
# SEE ALSO
#	local(8), local delivery agent
#	newaliases(1), create/update alias database
#	postalias(1), create/update alias database
#	postconf(5), configuration parameters
# README FILES
# .ad
# .fi
#	Use "\fBpostconf readme_directory\fR" or
#	"\fBpostconf html_directory\fR" to locate this information.
# .na
# .nf
#	DATABASE_README, Postfix lookup table overview
# LICENSE
# .ad
# .fi
#	The Secure Mailer license must be distributed with this software.
# AUTHOR(S)
#	Wietse Venema
#	IBM T.J. Watson Research
#	P.O. Box 704
#	Yorktown Heights, NY 10598, USA
#
#	Wietse Venema
#	Google, Inc.
#	111 8th Avenue
#	New York, NY 10011, USA
#--