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ALIASES(5)                                                          ALIASES(5)

       aliases - Postfix local alias database format


       The  <a href="aliases.5.html"><b>aliases</b>(5)</a>  table provides a system-wide mechanism to
       redirect mail for local recipients. The  redirections  are
       processed by the Postfix <a href="local.8.html"><b>local</b>(8)</a> delivery agent.

       Normally, the <a href="aliases.5.html"><b>aliases</b>(5)</a> table is specified as a text file
       that serves as input  to  the  <a href="postalias.1.html"><b>postalias</b>(1)</a>  command.  The
       result,  an  indexed file in <b>dbm</b> or <b>db</b> format, is used for
       fast lookup  by  the  mail  system.  Execute  the  command
       <b>newaliases</b>  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
       <b>.forward</b> files in their home directory.  Lines in per-user
       <b>.forward</b> files have the same syntax as the right-hand side
       of <a href="aliases.5.html"><b>aliases</b>(5)</a> entries.

       The format of the alias database input file is as follows:

       <b>o</b>      An alias definition has the form

                   <i>name</i>: <i>value1</i>, <i>value2</i>, <i>...</i>

       <b>o</b>      Empty lines and whitespace-only lines are  ignored,
              as  are  lines whose first non-whitespace character
              is a `#'.

       <b>o</b>      A logical line starts with non-whitespace  text.  A
              line  that starts with whitespace continues a logi-
              cal line.

       The <i>name</i> is a local address (no domain part).  Use  double
       quotes  when the name contains any special characters such
       as whitespace, `#', `:', or `@'. The  <i>name</i>  is  folded  to
       lowercase, in order to make database lookups case insensi-

       In addition, when an alias exists for <b>owner-</b><i>name</i>, delivery
       diagnostics  are  directed  to that address, instead of to
       the originator of the message.  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 undeliv-
       ered mail.

       The <i>value</i> contains one or more of the following:

              Mail is forwarded to <i>address</i>, which  is  compatible
              with the <a href="">RFC 822</a> standard.

              Mail  is  appended  to <i>/file/name</i>. See <a href="local.8.html"><b>local</b>(8)</a> for
              details of delivery to file.  Delivery is not  lim-
              ited  to regular files.  For example, to dispose of
              unwanted mail, deflect it to <b>/dev/null</b>.

              Mail is piped into <i>command</i>. Commands  that  contain
              special  characters,  such as whitespace, should be
              enclosed between double quotes.  See  <a href="local.8.html"><b>local</b>(8)</a>  for
              details of delivery to command.

              When the command fails, a limited amount of command
              output is mailed back  to  the  sender.   The  file
              <b>/usr/include/sysexits.h</b>  defines  the expected exit
              status codes. For example, use <b>"|exit 67"</b> to  simu-
              late  a  "user  unknown"  error,  and  <b>"|exit 0"</b> to
              implement an expensive black hole.

              Mail is sent to  the  destinations  listed  in  the
              named file.  Lines in <b>:include:</b> 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
              "|<i>command</i>" and <i>/file/name</i> is disallowed by default.
              To  enable,  edit  the  <b><a href="postconf.5.html#allow_mail_to_commands">allow_mail_to_commands</a></b>  and
              <b><a href="postconf.5.html#allow_mail_to_files">allow_mail_to_files</a></b> configuration parameters.

       When alias database search fails, and the recipient local-
       part  contains  the  optional  recipient  delimiter (e.g.,
       <i>user+foo</i>), the  search  is  repeated  for  the  unextended
       address (e.g., <i>user</i>).

       The   <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b>   parameter  controls
       whether an unmatched address extension  (<i>+foo</i>)  is  propa-
       gated to the result of table lookup.

       The <a href="local.8.html">local(8)</a> delivery agent always folds the search string
       to lowercase before database lookup.

       The <a href="local.8.html"><b>local</b>(8)</a> delivery agent disallows  regular  expression
       substitution  of $1 etc. in <b><a href="postconf.5.html#alias_maps">alias_maps</a></b>, because that would
       open a security hole.

       The <a href="local.8.html"><b>local</b>(8)</a> delivery agent will silently ignore  requests
       to  use  the <a href="proxymap.8.html"><b>proxymap</b>(8)</a> server within <b><a href="postconf.5.html#alias_maps">alias_maps</a></b>. Instead
       it will open the table directly.  Before  Postfix  version
       2.2,  the  <a href="local.8.html"><b>local</b>(8)</a>  delivery  agent will terminate with a
       fatal error.

       The following <a href="postconf.5.html"><b></b></a> parameters are especially  relevant.
       The  text  below  provides  only  a parameter summary. See
       <a href="postconf.5.html"><b>postconf</b>(5)</a> for more details including examples.

       <b><a href="postconf.5.html#alias_database">alias_database</a></b>
              List of alias databases that  are  updated  by  the
              <a href="newaliases.1.html"><b>newaliases</b>(1)</a> command.

       <b><a href="postconf.5.html#alias_maps">alias_maps</a></b>
              List  of  alias  databases  queried by the <a href="local.8.html"><b>local</b>(8)</a>
              delivery agent.

       <b><a href="postconf.5.html#allow_mail_to_commands">allow_mail_to_commands</a></b>
              Restrict the usage of  mail  delivery  to  external

       <b><a href="postconf.5.html#allow_mail_to_files">allow_mail_to_files</a></b>
              Restrict  the  usage  of  mail delivery to external

       <b><a href="postconf.5.html#expand_owner_alias">expand_owner_alias</a></b>
              When delivering to an alias that has an <b>owner-</b> 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.

       <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b>
              A  list  of  address rewriting or forwarding mecha-
              nisms that propagate an address extension from  the
              original  address  to  the  result. Specify zero or
              more  of  <b>canonical</b>,   <b>virtual</b>,   <b>alias</b>,   <b>forward</b>,
              <b>include</b>, or <b>generic</b>.

       <b><a href="postconf.5.html#owner_request_special">owner_request_special</a></b>
              Give  special treatment to <b>owner-</b><i>listname</i> and <i>list-</i>
              <i>name</i><b>-request</b> addresses.

       <b><a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b>
              Delimiter that separates  recipients  from  address

       Available in Postfix version 2.3 and later:

       <b><a href="postconf.5.html#frozen_delivered_to">frozen_delivered_to</a></b>
              Update  the <a href="local.8.html">local(8)</a> delivery agent's Delivered-To:
              address (see <a href="postconf.5.html#prepend_delivered_header">prepend_delivered_header</a>)  only  once,
              at  the  start  of  a  delivery;  do not update the
              Delivered-To: address while  expanding  aliases  or
              .forward files.

       <a href="">RFC 822</a> (ARPA Internet Text Messages)

<b>SEE ALSO</b>
       <a href="local.8.html">local(8)</a>, local delivery agent
       <a href="newaliases.1.html">newaliases(1)</a>, create/update alias database
       <a href="postalias.1.html">postalias(1)</a>, create/update alias database
       <a href="postconf.5.html">postconf(5)</a>, configuration parameters

       <a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview

       The Secure Mailer license must be  distributed  with  this

       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA

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