generic - Postfix generic table format


   postmap /etc/postfix/generic

   postmap -q "string" /etc/postfix/generic

   postmap -q - /etc/postfix/generic <inputfile


   The optional generic(5) table specifies an address mapping that applies
   when mail is delivered. This is the opposite of  canonical(5)  mapping,
   which applies when mail is received.

   Typically, one would use the generic(5) table on a system that does not
   have a  valid  Internet  domain  name  and  that  uses  something  like
   localdomain.local  instead.   The  generic(5) table is then used by the
   smtp(8) client to transform local mail addresses  into  valid  Internet
   mail  addresses  when mail has to be sent across the Internet.  See the
   EXAMPLE section at the end of this document.

   The generic(5) mapping affects  both  message  header  addresses  (i.e.
   addresses  that  appear inside messages) and message envelope addresses
   (for example, the addresses that are used in SMTP protocol commands).

   Normally, the generic(5) table is specified as a text file that  serves
   as input to the postmap(1) command.  The result, an indexed file in dbm
   or db format, is used for fast searching by the  mail  system.  Execute
   the  command  "postmap /etc/postfix/generic" to rebuild an indexed file
   after changing the corresponding text file.

   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,  or  lookups  can  be
   directed  to TCP-based server. In those case, the lookups are done in a
   slightly different way as described  below  under  "REGULAR  EXPRESSION


   The  search string is folded to lowercase before database lookup. As of
   Postfix 2.3, the search string is not case folded with  database  types
   such  as  regexp: or pcre: whose lookup fields can match both upper and
   lower case.


   The input format for the postmap(1) command is as follows:

   pattern result
          When  pattern  matches  a  mail  address,  replace  it  by   the
          corresponding result.

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

   multi-line text
          A logical line starts with  non-whitespace  text.  A  line  that
          starts with whitespace continues a logical line.


   With  lookups  from  indexed files such as DB or DBM, or from networked
   tables such as NIS, LDAP or SQL, patterns are tried  in  the  order  as
   listed below:

   user@domain address
          Replace  user@domain  by  address.  This  form  has  the highest

   user address
          Replace user@site by address when site is  equal  to  $myorigin,
          when  site  is listed in $mydestination, or when it is listed in
          $inet_interfaces or $proxy_interfaces.

   @domain address
          Replace other addresses in domain by address.  This form has the
          lowest precedence.


   The lookup result is subject to address rewriting:

   *      When  the  result  has the form @otherdomain, the result becomes
          the same user in otherdomain.

   *      When "append_at_myorigin=yes", append "@$myorigin" to  addresses
          without "@domain".

   *      When "append_dot_mydomain=yes", append ".$mydomain" to addresses
          without ".domain".


   When a mail address localpart contains the optional recipient delimiter
   (e.g.,  user+foo@domain),  the  lookup  order becomes: user+foo@domain,
   user@domain, user+foo, user, and @domain.

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


   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).

   Each pattern is a regular expression that  is  applied  to  the  entire
   address  being  looked  up.  Thus,  user@domain  mail addresses are not
   broken up into  their  user  and  @domain  constituent  parts,  nor  is
   user+foo broken up into user and foo.

   Patterns  are  applied  in the order as specified in the table, until a
   pattern is found that matches the search string.

   Results are the same as with indexed file lookups, with the  additional
   feature   that   parenthesized  substrings  from  the  pattern  can  be
   interpolated as $1, $2 and so on.


   This section describes how the table lookups change  when  lookups  are
   directed   to  a  TCP-based  server.  For  a  description  of  the  TCP
   client/server lookup protocol, see tcp_table(5).  This feature  is  not
   available up to and including Postfix version 2.4.

   Each  lookup operation uses the entire address once.  Thus, user@domain
   mail  addresses  are  not  broken  up  into  their  user  and   @domain
   constituent parts, nor is user+foo broken up into user and foo.

   Results are the same as with indexed file lookups.


   The  following shows a generic mapping with an indexed file.  When mail
   is sent to a remote host via SMTP, this replaces  his@localdomain.local
   by his ISP mail address, replaces her@localdomain.local by her ISP mail
   address, and replaces other local addresses by his ISP account, with an
   address extension of +local (this example assumes that the ISP supports
   "+" style address extensions).

       smtp_generic_maps = hash:/etc/postfix/generic

       his@localdomain.local   hisaccount@hisisp.example
       her@localdomain.local   heraccount@herisp.example
       @localdomain.local      hisaccount+local@hisisp.example

   Execute the command "postmap /etc/postfix/generic" whenever  the  table
   is  changed.   Instead of hash, some systems use dbm database files. To
   find out what tables your system supports  use  the  command  "postconf


   The table format does not understand quoting conventions.


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

          Address  mapping lookup table for envelope and header sender and
          recipient addresses while delivering mail via SMTP.

          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.

   Other parameters of interest:

          The  network  interface addresses that this system receives mail
          on.  You need to stop and  start  Postfix  when  this  parameter

          Other  interfaces that this machine receives mail on by way of a
          proxy agent or network address translator.

          List of domains that this mail system considers local.

          The domain that is appended to locally-posted mail.

          Give special treatment to owner-xxx and xxx-request addresses.


   postmap(1), Postfix lookup table manager
   postconf(5), configuration parameters
   smtp(8), Postfix SMTP client


   Use "postconf readme_directory" or "postconf html_directory" to  locate
   this information.
   ADDRESS_REWRITING_README, address rewriting guide
   DATABASE_README, Postfix lookup table overview
   STANDARD_CONFIGURATION_README, configuration examples


   The Secure Mailer license must be distributed with this software.


   A genericstable feature appears in the Sendmail MTA.

   This feature is available in Postfix 2.2 and later.


   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



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