ALIASES(5) ALIASES(5)
NAME
aliases - format of the Postfix alias database
SYNOPSIS
postalias [-c config_dir] [-v] [file_type:]input_file
DESCRIPTION
The aliases file provides a system-wide mechanism to redi-
rect mail for local recipients.
The file serves as input to the postalias(1) command. The
result, an indexed file in dbm or db 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 postfix reload command to eliminate the delay.
The input and output file formats are expected to be com-
patible 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
.forward files in their home directory. Lines in per-user
.forward files have the same syntax as the right-hand side
of aliases entries.
The format of the alias database input file is as follows:
o An alias definition has the form
name: value1, value2, ...
o Lines that begin with whitespace continue the pre-
vious line.
o Blank lines are ignored, as are lines beginning
with `#'.
The name is a local address (no domain part). Use double
quotes when the name contains any special characters such
as whitespace, `#', `:', or `@'. The name is folded to
lowercase, in order to make database lookups case insensi-
tive.
In addition, when an alias exists for owner-name, 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.
The value contains one or more of the following:
address
Mail is forwarded to address, which is compatible
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ALIASES(5) ALIASES(5)
with the RFC 822 standard.
/file/name
Mail is appended to /file/name. See local(8) for
details of delivery to file. Delivery is not lim-
ited to regular files. For example, to dispose of
unwanted mail, deflect it to /dev/null.
|command
Mail is piped into command. Commands that contain
special characters, such as whitespace, should be
enclosed between double quotes. See local(8) for
details of delivery to command.
When the command fails, a limited amount of command
output is mailed back to the sender. The file
/usr/include/sysexits.h defines the expected exit
status codes. For example, use |"exit 67" to simu-
late a "user unknown" error, and |"exit 0" to
implement an expensive black hole.
:include:/file/name
Mail is sent to the destinations listed in the
named file. Lines in :include: files have the same
syntax as the right-hand side of alias entries.
A destination can be any destination that is
described in this manual page. However, delivery to
"|command" and /file/name is disallowed by default.
To enable, edit the allow_mail_to_commands and
allow_mail_to_files configuration parameters.
ADDRESS EXTENSION
When alias database search fails, and the recipient local-
part contains the optional recipient delimiter (e.g.,
user+foo), the search is repeated for the unextended
address (e.g., user).
CONFIGURATION PARAMETERS
The following main.cf parameters are especially relevant
to this topic. See the Postfix main.cf file for syntax
details and for default values. Use the postfix reload
command after a configuration change.
alias_maps
List of alias databases.
allow_mail_to_commands
Restrict the usage of mail delivery to external
command.
allow_mail_to_files
Restrict the usage of mail delivery to external
file.
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ALIASES(5) ALIASES(5)
owner_request_special
Give special treatment to owner-xxx and xxx-request
addresses.
recipient_delimiter
Delimiter that separates recipients from address
extensions.
STANDARDS
RFC 822 (ARPA Internet Text Messages)
SEE ALSO
local(8) local delivery agent
postalias(1) alias database management
LICENSE
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
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