ALIASES(5)                                                          ALIASES(5)

       aliases - Postfix local alias database format


       postalias -q name [file-type]:[file-name]

       The  optional  aliases(5)  table  (alias_maps) redirects mail for local
       recipients. The redirections are  processed  by  the  Postfix  local(8)
       delivery  agent.  This  table  is always searched with an email address
       localpart (no domain portion).

       This is unlike virtual(5) aliasing (virtual_alias_maps)  which  applies
       to  all  recipients: local(8), virtual, and remote, and which is imple-
       mented by the cleanup(8) daemon. That table is often  searched  with  a
       full email address (including domain).

       Normally,  the aliases(5) 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.

       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

       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(5) 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 logical 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 insensitive.

       In addition, when an alias exists for owner-name,  this  will  override
       the  envelope sender address, so that delivery diagnostics are directed
       to owner-name, instead of the originator of the message  (for  details,
       see  owner_request_special,  expand_owner_alias and reset_owner_alias).
       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.

       The value contains one or more of the following:

              Mail is forwarded to address, which is compatible with  the  RFC
              822 standard.

              Mail  is  appended  to  /file/name. For details on how a file is
              written see the sections "EXTERNAL FILE DELIVERY" and  "DELIVERY
              RIGHTS"  in the local(8) documentation.  Delivery is not limited
              to regular files.  For example, to  dispose  of  unwanted  mail,
              deflect it to /dev/null.

              Mail  is piped into command. Commands that contain special char-
              acters, such as whitespace, should be  enclosed  between  double
              quotes.  For  details on how a command is executed see "EXTERNAL
              COMMAND DELIVERY" and "DELIVERY RIGHTS" in the local(8) documen-

              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 simulate a "user unknown" error, and "|exit 0" to  imple-
              ment an expensive black hole.

              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 aliases(5) 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_com-
              mands and allow_mail_to_files configuration parameters.

       When alias database search fails, and the recipient localpart  contains
       the  optional  recipient  delimiter  (e.g.,  user+foo),  the  search is
       repeated for the unextended address (e.g., user).

       The  propagate_unmatched_extensions  parameter  controls   whether   an
       unmatched address extension (+foo) is propagated to the result of table

       The local(8) delivery agent always folds the search string to lowercase
       before database lookup.

       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 regexp_table(5) or pcre_table(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 user+foo is not broken up into user and foo.

       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 $1, $2 etc. substring interpolation.

       The  local(8)  delivery agent disallows regular expression substitution
       of $1 etc. in alias_maps, because that would open a security hole.

       The local(8) delivery agent will silently ignore requests  to  use  the
       proxymap(8)  server  within  alias_maps. Instead it will open the table
       directly.  Before Postfix version 2.2, the local(8) delivery agent will
       terminate with a fatal error.

       The  following  parameters  are especially relevant.  The text
       below provides only a  parameter  summary.  See  postconf(5)  for  more
       details including examples.

       alias_database (see 'postconf -d' output)
              The  alias databases for local(8) delivery that are updated with
              "newaliases" or with "sendmail -bi".

       alias_maps (see 'postconf -d' output)
              Optional lookup tables with aliases that apply only to  local(8)
              recipients;  this is unlike virtual_alias_maps that apply to all
              recipients: local(8), virtual, and remote.

       allow_mail_to_commands (alias, forward)
              Restrict local(8) mail delivery to external commands.

       allow_mail_to_files (alias, forward)
              Restrict local(8) mail delivery to external files.

       expand_owner_alias (no)
              When  delivering  to  an   alias   "aliasname"   that   has   an
              "owner-aliasname"  companion  alias,  set  the  envelope  sender
              address to the expansion of the "owner-aliasname" alias.

       propagate_unmatched_extensions (canonical, virtual)
              What address lookup tables copy an address  extension  from  the
              lookup key to the lookup result.

       owner_request_special (yes)
              Enable  special  treatment  for  owner-listname  entries  in the
              aliases(5)  file,  and  don't  split  owner-listname  and  list-
              name-request  address localparts when the recipient_delimiter is
              set to "-".

       recipient_delimiter (empty)
              The set of characters that can separate an email address  local-
              part, user name, or a .forward file name from its extension.

       Available in Postfix version 2.3 and later:

       frozen_delivered_to (yes)
              Update  the  local(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.

       RFC 822 (ARPA Internet Text Messages)

       local(8), local delivery agent
       newaliases(1), create/update alias database
       postalias(1), create/update alias database
       postconf(5), configuration parameters

       DATABASE_README, Postfix lookup table overview

       The Secure Mailer license must be distributed with this software.

       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