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<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
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<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<title> Postfix manual - aliases(5) </title>
</head> <body> <pre>
ALIASES(5)                                                          ALIASES(5)

<b>NAME</b>
       aliases - Postfix local alias database format

<b>SYNOPSIS</b>
       <b>newaliases</b>

<b>DESCRIPTION</b>
       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.

       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
       "REGULAR EXPRESSION TABLES".

       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 logical 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 insensitive.

       In addition, when an alias exists for <b>owner-</b><i>name</i>,  this  will  override
       the  envelope sender address, so that delivery diagnostics are directed
       to <b>owner-</b><i>name</i>, instead of the originator of the message  (for  details,
       see  <b><a href="postconf.5.html#owner_request_special">owner_request_special</a></b>,  <b><a href="postconf.5.html#expand_owner_alias">expand_owner_alias</a></b> and <b><a href="postconf.5.html#reset_owner_alias">reset_owner_alias</a></b>).
       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 <i>value</i> contains one or more of the following:

       <i>address</i>
              Mail is forwarded to <i>address</i>, which is compatible with  the  <a href="http://tools.ietf.org/html/rfc822">RFC</a>
              <a href="http://tools.ietf.org/html/rfc822">822</a> standard.

       <i>/file/name</i>
              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  limited  to  regular  files.
              For  example,  to  dispose  of  unwanted  mail,  deflect  it  to
              <b>/dev/null</b>.

       |<i>command</i>
              Mail is piped into <i>command</i>. Commands that contain special  char-
              acters,  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</b>
              <b>67"</b>  to simulate a "user unknown" error, and <b>"|exit 0"</b> to imple-
              ment an expensive black hole.

       <b>:include:</b><i>/file/name</i>
              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_com</a>-</b>
              <b><a href="postconf.5.html#allow_mail_to_commands">mands</a></b> and <b><a href="postconf.5.html#allow_mail_to_files">allow_mail_to_files</a></b> configuration parameters.

<b>ADDRESS EXTENSION</b>
       When  alias database search fails, and the recipient localpart 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 propagated to the result of table
       lookup.

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

<b>REGULAR EXPRESSION TABLES</b>
       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 <a href="regexp_table.5.html"><b>regexp_table</b>(5)</a>  or  <a href="pcre_table.5.html"><b>pcre_table</b>(5)</a>.
       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 <i>user+foo</i> is not broken up into <i>user</i> and <i>foo</i>.

       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 <b>$1</b>, <b>$2</b> etc. substring interpolation.

<b>SECURITY</b>
       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.

<b>CONFIGURATION PARAMETERS</b>
       The following <a href="postconf.5.html"><b>main.cf</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> (see 'postconf -d' output)</b>
              The alias databases for <a href="local.8.html"><b>local</b>(8)</a> delivery that are updated  with
              "<b>newaliases</b>" or with "<b>sendmail -bi</b>".

       <b><a href="postconf.5.html#alias_maps">alias_maps</a> (see 'postconf -d' output)</b>
              The alias databases that are used for <a href="local.8.html"><b>local</b>(8)</a> delivery.

       <b><a href="postconf.5.html#allow_mail_to_commands">allow_mail_to_commands</a> (alias, forward)</b>
              Restrict <a href="local.8.html"><b>local</b>(8)</a> mail delivery to external commands.

       <b><a href="postconf.5.html#allow_mail_to_files">allow_mail_to_files</a> (alias, forward)</b>
              Restrict <a href="local.8.html"><b>local</b>(8)</a> mail delivery to external files.

       <b><a href="postconf.5.html#expand_owner_alias">expand_owner_alias</a> (no)</b>
              When   delivering   to   an   alias   "<i>aliasname</i>"  that  has  an
              "owner-<i>aliasname</i>"  companion  alias,  set  the  envelope  sender
              address to the expansion of the "owner-<i>aliasname</i>" alias.

       <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> (canonical, virtual)</b>
              What  address  lookup  tables copy an address extension from the
              lookup key to the lookup result.

       <b><a href="postconf.5.html#owner_request_special">owner_request_special</a> (yes)</b>
              Enable special  treatment  for  owner-<i>listname</i>  entries  in  the
              <a href="aliases.5.html"><b>aliases</b>(5)</a>  file,  and  don't  split  owner-<i>listname</i>  and  <i>list-</i>
              <i>name</i>-request address localparts when the <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a>  is
              set to "-".

       <b><a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> (empty)</b>
              The  set  of  characters  that can separate a user name from its
              extension (example: user+foo), or a .forward file name from  its
              extension (example: .forward+foo).

       Available in Postfix version 2.3 and later:

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

<b>STANDARDS</b>
       <a href="http://tools.ietf.org/html/rfc822">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

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

<b>LICENSE</b>
       The Secure Mailer license must be distributed with this software.

<b>AUTHOR(S)</b>
       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

                                                                    ALIASES(5)
</pre> </body> </html>