NetBSD/gnu/dist/postfix/man/man5/aliases.5

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.TH ALIASES 5
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.SH NAME
aliases
\-
format of the Postfix alias database
.SH SYNOPSIS
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\fBpostalias\fR [\fB-c\fR \fIconfig_dir\fR] [\fB-v\fR]
[\fIfile_type\fR:]\fIinput_file\fR
.SH DESCRIPTION
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The \fBaliases\fR file provides a system-wide mechanism to
redirect mail for local recipients.
The file 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. After an update
it may take a minute or so before the change becomes visible.
Issue a \fBpostfix reload\fR command to eliminate the delay.
The input and output file formats are expected to be compatible
with Sendmail version 8, and are expected to be suitable for the
use as NIS maps.
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 entries.
The format of the alias database input file is as follows:
.IP \(bu
An alias definition has the form
.sp
.ti +5
\fIname\fR: \fIvalue1\fR, \fIvalue2\fR, \fI...\fR
.IP \(bu
Lines that begin with whitespace continue the previous line.
.IP \(bu
Blank lines are ignored, as are lines beginning with `#'.
.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, delivery
diagnostics are directed to that address, instead of to the originator.
This is typically used to direct delivery errors to the owner 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.
.SH ADDRESS EXTENSION
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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).
.SH CONFIGURATION PARAMETERS
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The following \fBmain.cf\fR parameters are especially relevant to
this topic. See the Postfix \fBmain.cf\fR file for syntax details
and for default values. Use the \fBpostfix reload\fR command after
a configuration change.
.IP \fBalias_maps\fR
List of alias databases.
.IP \fBallow_mail_to_commands\fR
Restrict the usage of mail delivery to external command.
.IP \fBallow_mail_to_files\fR
Restrict the usage of mail delivery to external file.
.IP \fBowner_request_special\fR
Give special treatment to \fBowner-\fIxxx\fR and \fIxxx\fB-request\fR
addresses.
.IP \fBrecipient_delimiter\fR
Delimiter that separates recipients from address extensions.
.SH STANDARDS
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RFC 822 (ARPA Internet Text Messages)
.SH SEE ALSO
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local(8) local delivery agent
postalias(1) alias database management
.SH LICENSE
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The Secure Mailer license must be distributed with this software.
.SH AUTHOR(S)
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Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA