ALIASES(5)                                             ALIASES(5)
NAME
       aliases - format of the Postfix alias database
SYNOPSIS
       newaliases
DESCRIPTION
       The  aliases  table  provides  a  system-wide mechanism to
       redirect mail for local recipients. The  redirections  are
       processed by the Postfix local(8) delivery agent.
       Normally,  the  aliases  table is specified as a text file
       that 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.  Execute  the  command
       newaliases  in  order  to  rebuild  the indexed file after
       changing the Postfix alias database.
       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      Empty lines and whitespace-only lines are  ignored,
              as  are  lines whose first non-whitespace character
              is a `#'.
       o      A logical line starts with non-whitespace  text.  A
              line  that starts with whitespace continues a logi-
              cal line.
       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
              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.
       expand_owner_alias
              When delivering to an alias that has an owner- com-
              panion alias, set the envelope  sender  address  to
              the  right-hand  side  of  the owner alias, instead
              using of the left-hand side address.
       owner_request_special
              Give special treatment to owner-xxx and xxx-request
              addresses.
       recipient_delimiter
              Delimiter  that  separates  recipients from address
              extensions.
BUGS
       Regular expression alias lookup tables  are  allowed,  but
       substitution  of  $1  etc. is forbidden because that would
       open a security loophole.
STANDARDS
       RFC 822 (ARPA Internet Text Messages)
SEE ALSO
       local(8) local delivery agent
       newaliases(1) alias database management
       regexp_table(5) POSIX regular expression table format
       pcre_table(5) Perl Compatible Regular Expression table format
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
                                                       ALIASES(5)