# VIRTUAL(5)                                             VIRTUAL(5)
# 
# NAME
#        virtual - format of Postfix virtual alias table
# 
# SYNOPSIS
#        postmap /etc/postfix/virtual
# 
#        postmap -q "string" /etc/postfix/virtual
# 
#        postmap -q - /etc/postfix/virtual <inputfile
# 
# DESCRIPTION
#        The  optional virtual alias table specifies address alias-
#        ing for arbitrary 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   recipient
#               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) map-
#        ping 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 expres-
#        sions. In that case, the lookups are done  in  a  slightly
#        different way as described below.
# 
# TABLE FORMAT
#        The  format  of  the virtual table is as follows, mappings
#        being tried in the order as listed in this manual page:
# 
#        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  logi-
#               cal 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 @other-
#        domain, the result is the same user in otherdomain.   This
#        works for the first address in the expansion only.
# 
# ADDRESS EXTENSION
#        When a mail address localpart contains the optional recip-
#        ient delimiter (e.g., user+foo@domain), the  lookup  order
#        becomes: user+foo@domain, user@domain, user+foo, user, and
#        @domain.  An unmatched address extension (+foo) is  propa-
#        gated to the result of table lookup.
# 
# VIRTUAL ALIAS DOMAINS
#        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 vir-
#        tual 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:
# 
#        /etc/postfix/main.cf:
#            virtual_alias_maps = hash:/etc/postfix/virtual
# 
#            Note: some systems use dbm databases instead of  hash.
#            See the output from postconf -m for available database
#            types.
# 
#        /etc/postfix/virtual:
#            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@virtual-alias.domain   as
#        undeliverable.
# 
#        Instead  of  specifying  the virtual alias domain name via
#        the virtual_alias_maps table, you may also specify it  via
#        the main.cf virtual_alias_domains configuration parameter.
#        This latter parameter uses the same syntax as the  main.cf
#        mydestination configuration parameter.
# 
# 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).
# 
#        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.
# 
# BUGS
#        The table format does not understand quoting  conventions.
# 
# CONFIGURATION PARAMETERS
#        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.
# 
#        virtual_alias_maps
#               List of virtual aliasing tables.
# 
#        virtual_alias_domains
#               List of virtual alias domains. This uses  the  same
#               syntax as the mydestination parameter.
# 
#        Other parameters of interest:
# 
#        inet_interfaces
#               The  network  interface  addresses that this system
#               receives mail on.  You need to stop and start Post-
#               fix when this parameter changes.
# 
#        mydestination
#               List  of  domains  that  this mail system considers
#               local.
# 
#        myorigin
#               The domain that is appended  to  any  address  that
#               does not have a domain.
# 
#        owner_request_special
#               Give special treatment to owner-xxx and xxx-request
#               addresses.
# 
# SEE ALSO
#        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
# 
# 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
# 
#                                                        VIRTUAL(5)
