# VIRTUAL(5)                                                          VIRTUAL(5)
# 
# NAME
#        virtual - Postfix virtual alias table format
# 
# SYNOPSIS
#        postmap /etc/postfix/virtual
# 
#        postmap -q "string" /etc/postfix/virtual
# 
#        postmap -q - /etc/postfix/virtual <inputfile
# 
# DESCRIPTION
#        The  optional  virtual(5)  alias  table rewrites recipient
#        addresses for all local, all virtual, and all remote  mail
#        destinations.   This  is unlike the aliases(5) table which
#        is used only for local(8) delivery. This feature is imple-
#        mented  in  the  Postfix  cleanup(8) daemon before mail is
#        queued.
# 
#        Virtual aliasing is recursive; to terminate recursion  for
#        a specific address, alias that address to itself.
# 
#        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.  Use
#        canonical(5)  mapping  to  rewrite  header  and   envelope
#        addresses in general.
# 
#        Normally,  the  virtual(5)  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" 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  regu-
#        lar-expression  map  where  patterns  are given as regular
#        expressions, or lookups can be  directed  to  a  TCP-based
#        server.  In those case, the lookups are done in a slightly
#        different way as described below under "REGULAR EXPRESSION
#        TABLES" or "TCP-BASED TABLES".
# 
# CASE FOLDING
#        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.
# 
# TABLE FORMAT
#        The input format for the postmap(1) command is as follows:
# 
#        pattern address, address, ...
#               When  pattern matches a mail address, replace it by
#               the corresponding address.
# 
#        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.
# 
# TABLE SEARCH ORDER
#        With lookups from indexed files such as DB or DBM, or from
#        networked   tables   such   as  NIS,  LDAP  or  SQL,  each
#        user@domain query produces a sequence of query patterns as
#        described below.
# 
#        Each  query pattern is sent to each specified lookup table
#        before trying the next query pattern,  until  a  match  is
#        found.
# 
#        user@domain address, address, ...
#               Redirect  mail  for  user@domain  to address.  This
#               form has the highest precedence.
# 
#        user address, address, ...
#               Redirect mail for user@site to address when site is
#               equal  to $myorigin, when site is listed in $mydes-
#               tination, or when it is listed in  $inet_interfaces
#               or $proxy_interfaces.
# 
#               This  functionality overlaps with the functionality
#               of the local aliases(5) database. The difference is
#               that virtual(5) mapping can be applied to non-local
#               addresses.
# 
#        @domain address, address, ...
#               Redirect mail for other users in domain to address.
#               This form has the lowest precedence.
# 
#               Note:  @domain  is a wild-card. With this form, the
#               Postfix SMTP server accepts mail for any  recipient
#               in  domain,  regardless  of  whether that recipient
#               exists.  This may turn  your  mail  system  into  a
#               backscatter  source: Postfix first accepts mail for
#               non-existent recipients and then  tries  to  return
#               that  mail  as  "undeliverable" to the often forged
#               sender address.
# 
#               To avoid backscatter  with  mail  for  a  wild-card
#               domain, replace the wild-card mapping with explicit
#               1:1 mappings, or add a  reject_unverified_recipient
#               restriction for that domain:
# 
#                   smtpd_recipient_restrictions =
#                       ...
#                       reject_unauth_destination
#                       check_recipient_access
#                           inline:{example.com=reject_unverified_recipient}
#                   unverified_recipient_reject_code = 550
# 
#               In  the above example, Postfix may contact a remote
#               server if the recipient  is  aliased  to  a  remote
#               address.
# 
# RESULT ADDRESS REWRITING
#        The lookup result is subject to address rewriting:
# 
#        o      When  the  result  has  the  form @otherdomain, the
#               result becomes the same user in otherdomain.   This
#               works only for the first address in a multi-address
#               lookup result.
# 
#        o      When "append_at_myorigin=yes", append  "@$myorigin"
#               to addresses without "@domain".
# 
#        o      When "append_dot_mydomain=yes", append ".$mydomain"
#               to addresses without ".domain".
# 
# 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.
# 
#        The   propagate_unmatched_extensions   parameter  controls
#        whether an unmatched address extension  (+foo)  is  propa-
#        gated to the result of a 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  ta-
#        ble,  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, $2 and so on.
# 
# TCP-BASED TABLES
#        This section describes how the table lookups  change  when
#        lookups are directed to a TCP-based server. For a descrip-
#        tion of the TCP client/server lookup protocol, see tcp_ta-
#        ble(5).   This  feature  is  available  in Postfix 2.5 and
#        later.
# 
#        Each lookup operation uses the entire address once.  Thus,
#        user@domain  mail  addresses  are not broken up into their
#        user and @domain constituent parts, nor is user+foo broken
#        up into user and foo.
# 
#        Results are the same as with indexed file lookups.
# 
# BUGS
#        The  table format does not understand quoting conventions.
# 
# CONFIGURATION PARAMETERS
#        The following main.cf parameters are  especially  relevant
#        to  this  topic.  See  the Postfix main.cf file for syntax
#        details and for default values. Use the  "postfix  reload"
#        command after a configuration change.
# 
#        virtual_alias_maps ($virtual_maps)
#               Optional  lookup  tables  that  alias specific mail
#               addresses or  domains  to  other  local  or  remote
#               addresses.
# 
#        virtual_alias_domains ($virtual_alias_maps)
#               Postfix  is the final destination for the specified
#               list of virtual alias domains, that is, domains for
#               which  all  addresses  are  aliased to addresses in
#               other local or remote domains.
# 
#        propagate_unmatched_extensions (canonical, virtual)
#               What address lookup tables copy an  address  exten-
#               sion from the lookup key to the lookup result.
# 
#        Other parameters of interest:
# 
#        inet_interfaces (all)
#               The network interface addresses that this mail sys-
#               tem receives mail on.
# 
#        mydestination  ($myhostname,  localhost.$mydomain,  local-
#        host)
#               The list of domains  that  are  delivered  via  the
#               $local_transport mail delivery transport.
# 
#        myorigin ($myhostname)
#               The domain name that locally-posted mail appears to
#               come from, and that locally posted mail  is  deliv-
#               ered to.
# 
#        owner_request_special (yes)
#               Enable special treatment for owner-listname entries
#               in the aliases(5) file, and don't split owner-list-
#               name  and  listname-request address localparts when
#               the recipient_delimiter is set to "-".
# 
#        proxy_interfaces (empty)
#               The network interface addresses that this mail sys-
#               tem  receives  mail on by way of a proxy or network
#               address translation unit.
# 
# SEE ALSO
#        cleanup(8), canonicalize and enqueue mail
#        postmap(1), Postfix lookup table manager
#        postconf(5), configuration parameters
#        canonical(5), canonical address mapping
# 
# README FILES
#        Use "postconf readme_directory" or  "postconf  html_direc-
#        tory" to locate this information.
#        ADDRESS_REWRITING_README, address rewriting guide
#        DATABASE_README, Postfix lookup table overview
#        VIRTUAL_README, domain hosting guide
# 
# 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
# 
#                                                                     VIRTUAL(5)
