# CANONICAL(5)                                                      CANONICAL(5)
# 
# NAME
#        canonical - Postfix canonical table format
# 
# SYNOPSIS
#        postmap /etc/postfix/canonical
# 
#        postmap -q "string" /etc/postfix/canonical
# 
#        postmap -q - /etc/postfix/canonical <inputfile
# 
# DESCRIPTION
#        The  optional canonical(5) table specifies an address map-
#        ping for local and non-local  addresses.  The  mapping  is
#        used  by the cleanup(8) daemon, before mail is stored into
#        the queue.  The address mapping is recursive.
# 
#        Normally, the canonical(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/canonical"  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 expres-
#        sions,  or lookups can be directed to TCP-based server. In
#        those cases, the lookups are done in a slightly  different
#        way  as  described below under "REGULAR EXPRESSION TABLES"
#        or "TCP-BASED TABLES".
# 
#        By default the canonical(5) mapping affects  both  message
#        header  addresses  (i.e. addresses that appear inside mes-
#        sages) and message envelope addresses  (for  example,  the
#        addresses  that  are used in SMTP protocol commands). This
#        is controlled with the canonical_classes parameter.
# 
#        NOTE: Postfix versions 2.2 and later rewrite message head-
#        ers  from  remote  SMTP clients only if the client matches
#        the  local_header_rewrite_clients  parameter,  or  if  the
#        remote_header_rewrite_domain configuration parameter spec-
#        ifies a non-empty value. To get the behavior before  Post-
#        fix    2.2,    specify   "local_header_rewrite_clients   =
#        static:all".
# 
#        Typically, one would use the canonical(5) table to replace
#        login   names   by  Firstname.Lastname,  or  to  clean  up
#        addresses produced by legacy mail systems.
# 
#        The canonical(5) mapping is not to be confused  with  vir-
#        tual  alias  support or with local aliasing. To change the
#        destination but not the headers,  use  the  virtual(5)  or
#        aliases(5) map instead.
# 
# 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 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.
# 
# 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
#               Replace user@domain by address. This form  has  the
#               highest precedence.
# 
#               This  is  useful  to clean up addresses produced by
#               legacy mail systems.  It can also be used  to  pro-
#               duce  Firstname.Lastname  style  addresses, but see
#               below for a simpler solution.
# 
#        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
#               $proxy_interfaces.
# 
#               This  form  is  useful for replacing login names by
#               Firstname.Lastname.
# 
#        @domain address
#               Replace other addresses in domain by address.  This
#               form has the lowest precedence.
# 
#               Note:  @domain  is  a  wild-card. When this form is
#               applied to recipient addresses,  the  Postfix  SMTP
#               server  accepts  mail  for any recipient in domain,
#               regardless of whether that recipient exists.   This
#               may  turn  your  mail  system  into  a  backscatter
#               source: Postfix first accepts mail for non-existent
#               recipients  and  then  tries to return that mail as
#               "undeliverable" to the often forged sender address.
# 
# RESULT ADDRESS REWRITING
#        The lookup result is subject to address rewriting:
# 
#        o      When  the  result  has  the  form @otherdomain, the
#               result becomes the same user in otherdomain.
# 
#        o      When "append_at_myorigin=yes", append  "@$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 table 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).
# 
#        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 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.
# 
# BUGS
#        The  table format does not understand quoting conventions.
# 
# 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.
# 
#        canonical_classes
#               What addresses are  subject  to  canonical  address
#               mapping.
# 
#        canonical_maps
#               List of canonical mapping tables.
# 
#        recipient_canonical_maps
#               Address  mapping  lookup  table  for  envelope  and
#               header recipient addresses.
# 
#        sender_canonical_maps
#               Address  mapping  lookup  table  for  envelope  and
#               header sender addresses.
# 
#        propagate_unmatched_extensions
#               A  list  of  address rewriting or forwarding mecha-
#               nisms 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:
# 
#        inet_interfaces
#               The  network  interface  addresses that this system
#               receives mail on.  You need to stop and start Post-
#               fix when this parameter changes.
# 
#        local_header_rewrite_clients
#               Rewrite message header addresses in mail from these
#               clients and update incomplete  addresses  with  the
#               domain name in $myorigin or $mydomain; either don't
#               rewrite message headers from other clients at  all,
#               or  rewrite  message  headers and update incomplete
#               addresses  with  the  domain   specified   in   the
#               remote_header_rewrite_domain parameter.
# 
#        proxy_interfaces
#               Other interfaces that this machine receives mail on
#               by way of a proxy agent or network address transla-
#               tor.
# 
#        masquerade_classes
#               List  of  address  classes subject to masquerading:
#               zero or more of  envelope_sender,  envelope_recipi-
#               ent, header_sender, header_recipient.
# 
#        masquerade_domains
#               List  of  domains  that hide their subdomain struc-
#               ture.
# 
#        masquerade_exceptions
#               List of user names that are not subject to  address
#               masquerading.
# 
#        mydestination
#               List  of  domains  that  this mail system considers
#               local.
# 
#        myorigin
#               The domain that is appended to locally-posted mail.
# 
#        owner_request_special
#               Give special treatment to owner-xxx and xxx-request
#               addresses.
# 
#        remote_header_rewrite_domain
#               Don't rewrite message headers from  remote  clients
#               at all when this parameter is empty; otherwise, re-
#               write message  headers  and  append  the  specified
#               domain name to incomplete addresses.
# 
# SEE ALSO
#        cleanup(8), canonicalize and enqueue mail
#        postmap(1), Postfix lookup table manager
#        postconf(5), configuration parameters
#        virtual(5), virtual aliasing
# 
# README FILES
#        Use  "postconf  readme_directory" or "postconf html_direc-
#        tory" to locate this information.
#        DATABASE_README, Postfix lookup table overview
#        ADDRESS_REWRITING_README, address rewriting 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
# 
#                                                                   CANONICAL(5)
