Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (NetBSD-2.0)
Apropos / Subsearch:
optional field

VIRTUAL(5)                    File Formats Manual                   VIRTUAL(5)

       virtual - format of Postfix virtual alias table

       postmap /etc/postfix/virtual

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

       postmap -q - /etc/postfix/virtual <&lt;inputfile

       The  optional  virtual alias table specifies address aliasing for arbi-
       trary local or  non-local  recipient  addresses.  Virtual  aliasing  is
       recursive, and is done by the Postfix cleanup(8) daemon.

       The main applications of virtual aliasing are:

       o      To redirect mail for one address to one or more addresses.

       o      To  implement  virtual  alias  domains  where  all addresses are
              aliased to addresses in other domains.

              Virtual alias domains are not to be confused  with  the  virtual
              mailbox domains that are implemented with the Postfix virtual(8)
              mail delivery agent. With virtual mailbox domains, each  recipi-
              ent address can have its own mailbox.

       Virtual  aliasing  is applied only to recipient envelope addresses, and
       does not affect message headers.  Think Sendmail rule set  S0,  if  you
       like. Use canonical(5) mapping to rewrite header and envelope addresses
       in general.

       Normally, the virtual alias 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/virtual in order to rebuild
       the indexed file after changing the 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.  In  that  case,  the
       lookups are done in a slightly different way as described below.

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

       pattern result
              When  pattern  matches  a mail address, replace it by the corre-
              sponding 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, address, ...
              Mail for user@domain is redirected to address.   This  form  has
              the highest precedence.

       user address, address, ...
              Mail  for  user@site is redirected to address when site is equal
              to $myorigin, when site is listed in $mydestination, or when  it
              is listed in $inet_interfaces.

              This  functionality  overlaps  with  functionality  of the local
              aliases(5) database. The difference is that virtual mapping  can
              be applied to non-local addresses.

       @domain address, address, ...
              Mail for any user in domain is redirected to address.  This form
              has the lowest precedence.

       In all the above forms, when address has  the  form  @otherdomain,  the
       result  is  the  same  user  in  otherdomain.  This works for the first
       address in the expansion only.

       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.  An unmatched address  exten-
       sion (+foo) is propagated to the result of table lookup.

       Besides  virtual  aliases,  the virtual alias table can also be used to
       implement virtual alias domains.  With  a  virtual  alias  domain,  all
       recipient addresses are aliased to addresses in other domains.

       Virtual  alias  domains are not to be confused with the virtual mailbox
       domains that are implemented with the Postfix virtual(8) mail  delivery
       agent.  With  virtual  mailbox domains, each recipient address can have
       its own mailbox.

       With a virtual alias domain, the virtual domain has its own  user  name
       space.  Local (i.e. non-virtual) usernames are not visible in a virtual
       alias domain. In particular, local aliases(5) and local  mailing  lists
       are not visible as localname@virtual-alias.domain.

       Support for a virtual alias domain looks like:

           virtual_alias_maps = hash:/etc/postfix/virtual

           Note: some systems use dbm databases instead of hash.  See the out-
           put from postconf -m for available database types.

           virtual-alias.domain anything (right-hand content does not matter)
           postmaster@virtual-alias.domain      postmaster
           user1@virtual-alias.domain   address1
           user2@virtual-alias.domain   address2, address3

       The virtual-alias.domain anything entry is required for a virtual alias
       domain.  Without  this  entry,  mail  is  rejected  with  "relay access
       denied", or bounces with "mail loops back to myself".

       Do not specify virtual alias domain names in the main.cf  mydestination
       or relay_domains configuration parameters.

       With  a  virtual alias domain, the Postfix SMTP server accepts mail for
       known-user@virtual-alias.domain, and rejects mail for unknown-user@vir-
       tual-alias.domain as undeliverable.

       Instead  of  specifying  the  virtual  alias  domain  name via the vir-
       tual_alias_maps table, you may also specify it  via  the  main.cf  vir-
       tual_alias_domains configuration parameter.  This latter parameter uses
       the same syntax as the main.cf mydestination configuration parameter.

       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 bro-
       ken 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 interpo-
       lated as $1, $2 and so on.

       The table format does not understand quoting conventions.

       The following main.cf parameters are especially relevant to this topic.
       See the Postfix main.cf file for syntax details and for default values.
       Use the postfix reload command after a configuration change.

              List of virtual aliasing tables.

              List of virtual alias domains. This uses the same syntax as  the
              mydestination parameter.

       Other parameters of interest:

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

              List of domains that this mail system considers local.

              The  domain that is appended to any address that does not have a

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

       cleanup(8) canonicalize and enqueue mail
       postmap(1) create mapping table
       regexp_table(5) POSIX regular expression table format
       pcre_table(5) Perl Compatible Regular Expression table format

       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