# TRANSPORT(5)                                         TRANSPORT(5)
# 
# NAME
#        transport - format of Postfix transport table
# 
# SYNOPSIS
#        postmap /etc/postfix/transport
# 
#        postmap -q "string" /etc/postfix/transport
# 
#        postmap -q - /etc/postfix/transport <inputfile
# 
# DESCRIPTION
#        The  optional  transport  table  specifies  a mapping from
#        email addresses  to  message  delivery  transports  and/or
#        relay hosts. The mapping is used by the trivial-rewrite(8)
#        daemon.
# 
#        This mapping overrides the default routing that  is  built
#        into Postfix:
# 
#        mydestination
#               A  list of domains that is by default delivered via
#               $local_transport.
# 
#        virtual_mailbox_domains
#               A list of domains that is by default delivered  via
#               $virtual_transport.
# 
#        relay_domains
#               A  list of domains that is by default delivered via
#               $relay_transport.
# 
#        any other destination
#               Mail for any other destination is by default deliv-
#               ered via $default_transport.
# 
#        Normally,  the transport 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/transport  in  order  to rebuild the
#        indexed file after changing the transport table.
# 
#        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
#        that  case,  the  lookups are done in a slightly different
#        way as described below under "REGULAR  EXPRESSION  TABLES"
#        and "TCP-BASED TABLES".
# 
# TABLE FORMAT
#        The input format for the postmap(1) command is as follows:
# 
#        pattern result
#               When  pattern  matches  the  recipient  address  or
#               domain, use 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.
# 
#        The  pattern specifies an email address, a domain name, or
#        a domain name hierarchy, as described  in  section  "TABLE
#        LOOKUP".
# 
#        The  result  is of the form transport:nexthop.  The trans-
#        port field specifies a mail  delivery  transport  such  as
#        smtp  or  local. The nexthop field specifies where and how
#        to deliver mail. More details are given in section "RESULT
#        FORMAT".
# 
# TABLE LOOKUP
#        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+extension@domain transport:nexthop
#               Mail for user+extension@domain is delivered through
#               transport to nexthop.
# 
#        user@domain transport:nexthop
#               Mail for user@domain is delivered through transport
#               to nexthop.
# 
#        domain transport:nexthop
#               Mail  for  domain is delivered through transport to
#               nexthop.
# 
#        .domain transport:nexthop
#               Mail for  any  subdomain  of  domain  is  delivered
#               through  transport  to  nexthop.  This applies only
#               when the string transport_maps is not listed in the
#               parent_domain_matches_subdomains configuration set-
#               ting.  Otherwise, a domain name matches itself  and
#               its subdomains.
# 
#        Note 1: the special pattern * represents any address (i.e.
#        it functions as the wild-card pattern).
# 
#        Note 2:  the  null  recipient  address  is  looked  up  as
#        $empty_address_recipient@$myhostname (default: mailer-dae-
#        mon@hostname).
# 
# RESULT FORMAT
#        The transport field specifies the name of a mail  delivery
#        transport (the first name of a mail delivery service entry
#        in the Postfix master.cf file).
# 
#        The interpretation  of  the  nexthop  field  is  transport
#        dependent. In the case of SMTP, specify host:service for a
#        non-default server port, and use [host] or [host]:port  in
#        order  to  disable MX (mail exchanger) DNS lookups. The []
#        form is required when you specify an IP address instead of
#        a hostname.
# 
#        A  null  transport  and  null nexthop result means "do not
#        change": use the delivery transport and  nexthop  informa-
#        tion  that  would  be used when the entire transport table
#        did not exist.
# 
#        A non-null transport  field  with  a  null  nexthop  field
#        resets the nexthop information to the recipient domain.
# 
#        A  null  transport  field with non-null nexthop field does
#        not modify the transport information.
# 
# EXAMPLES
#        In order to deliver internal mail directly, while using  a
#        mail  relay  for  all other mail, specify a null entry for
#        internal destinations (do not change the  delivery  trans-
#        port  or  the  nexthop information) and specify a wildcard
#        for all other destinations.
# 
#             my.domain    :
#             .my.domain   :
#             *         smtp:outbound-relay.my.domain
# 
#        In order to send mail for foo.org and its  subdomains  via
#        the uucp transport to the UUCP host named foo:
# 
#             foo.org      uucp:foo
#             .foo.org     uucp:foo
# 
#        When  no  nexthop  host name is specified, the destination
#        domain name is used instead. For  example,  the  following
#        directs  mail for user@foo.org via the slow transport to a
#        mail exchanger for foo.org.  The slow transport  could  be
#        something  that  runs  at  most  one delivery process at a
#        time:
# 
#             foo.org      slow:
# 
#        When no transport is specified, Postfix uses the transport
#        that matches the address domain class (see TRANSPORT FIELD
#        discussion above).   The  following  sends  all  mail  for
#        foo.org and its subdomains to host gateway.foo.org:
# 
#             foo.org      :[gateway.foo.org]
#             .foo.org     :[gateway.foo.org]
# 
#        In  the  above  example,  the  []  are used to suppress MX
#        lookups.  The result would  likely  point  to  your  local
#        machine.
# 
#        In  the  case  of delivery via SMTP, one may specify host-
#        name:service instead of just a host:
# 
#             foo.org      smtp:bar.org:2025
# 
#        This directs mail for user@foo.org to  host  bar.org  port
#        2025.  Instead  of a numerical port a symbolic name may be
#        used. Specify [] around the hostname in order  to  disable
#        MX lookups.
# 
#        The error mailer can be used to bounce mail:
# 
#             .foo.org       error:mail for *.foo.org is not deliv-
#        erable
# 
#        This causes  all  mail  for  user@anything.foo.org  to  be
#        bounced.
# 
# 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,
#        some.domain.hierarchy is not looked up up via  its  parent
#        domains,  nor is user+foo@domain looked up as user@domain.
# 
#        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.
# 
# 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_table(5).
# 
#        Each  lookup  operation  uses the entire recipient address
#        once.  Thus, some.domain.hierarchy is not  looked  up  via
#        its  parent  domains,  nor is user+foo@domain looked up as
#        user@domain.
# 
#        Results are the same as with indexed file lookups.
# 
# 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.
# 
#        empty_address_recipient
#               The  address  that is looked up instead of the null
#               sender address.
# 
#        parent_domain_matches_subdomains
#               List of Postfix features that use  domain.tld  pat-
#               terns   to  match  sub.domain.tld  (as  opposed  to
#               requiring .domain.tld patterns).
# 
#        transport_maps
#               List of transport lookup tables.
# 
# SEE ALSO
#        postmap(1) create mapping table
#        trivial-rewrite(8) rewrite and resolve addresses
#        pcre_table(5) format of PCRE tables
#        regexp_table(5) format of POSIX regular expression tables
#        tcp_table(5) TCP client/server table lookup protocol
# 
# 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
# 
#                                                      TRANSPORT(5)
