Provided by: postfix_3.1.0-3ubuntu0.4_amd64 bug

NAME

       aliases - Postfix local alias database format

SYNOPSIS

       newaliases

DESCRIPTION

       The  aliases(5)  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(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
       "REGULAR EXPRESSION TABLES".

       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:

       •      An alias definition has the form

                   name: value1, value2, ...

       •      Empty  lines  and  whitespace-only  lines  are  ignored,  as  are lines whose first non-whitespace
              character is a `#'.

       •      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, 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 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
              limited 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
              simulate 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 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 lookup.

CASE FOLDING

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

REGULAR EXPRESSION TABLES

       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.

SECURITY

       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.

CONFIGURATION PARAMETERS

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

       alias_database
              List of alias databases that are updated by the newaliases(1) command.

       alias_maps
              List of alias databases queried by the local(8) delivery agent.

       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- companion alias, set the envelope sender address to
              the right-hand side of the owner alias, instead using of the left-hand side address.

       propagate_unmatched_extensions
              A  list of address rewriting or forwarding mechanisms that propagate an address extension from the
              original address to the result. Specify zero  or  more  of  canonical,  virtual,  alias,  forward,
              include, or generic.

       owner_request_special
              Give special treatment to owner-listname and listname-request addresses.

       recipient_delimiter
              Delimiter that separates recipients from address extensions.

       Available in Postfix version 2.3 and later:

       frozen_delivered_to
              Update  the  local(8)  delivery  agent's Delivered-To: address (see prepend_delivered_header) only
              once, at the start of a delivery; do not update the Delivered-To: address while expanding  aliases
              or .forward files.

STANDARDS

       RFC 822 (ARPA Internet Text Messages)

SEE ALSO

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

README FILES

       Use "postconf readme_directory" or "postconf html_directory" to locate this information.
       DATABASE_README, Postfix lookup table overview

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

       Wietse Venema
       Google, Inc.
       111 8th Avenue
       New York, NY 10011, USA

                                                                                                      ALIASES(5)