# TRANSPORT(5)                                         TRANSPORT(5)
# 
# NAME
#        transport - Postfix transport table format
# 
# SYNOPSIS
#        postmap /usr/local/etc/postfix/transport
# 
#        postmap -q "string" /usr/local/etc/postfix/transport
# 
#        postmap -q - /usr/local/etc/postfix/transport <inputfile
# 
# DESCRIPTION
#        The  optional  transport(5) 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. This also includes  domains  that
#               match $inet_interfaces or $proxy_interfaces.
# 
#        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(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 /usr/local/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 and  specifies
#        how or where to deliver mail. This is described in section
#        "RESULT FORMAT".
# 
# TABLE SEARCH ORDER
#        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
#               Deliver  mail  for  user+extension@domain   through
#               transport to nexthop.
# 
#        user@domain transport:nexthop
#               Deliver  mail  for user@domain through transport to
#               nexthop.
# 
#        domain transport:nexthop
#               Deliver mail for domain through transport  to  nex-
#               thop.
# 
#        .domain transport:nexthop
#               Deliver  mail  for  any subdomain of domain through
#               transport to nexthop. This applies  only  when  the
#               string  transport_maps  is  not  listed in the par-
#               ent_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).
# 
#        Note  3:  user@domain  or  user+extension@domain lookup is
#        available in Postfix 2.0 and later.
# 
# RESULT FORMAT
#        The lookup result is of the form  transport:nexthop.   The
#        transport  field  specifies a mail delivery transport such
#        as smtp or local. The nexthop field  specifies  where  and
#        how to deliver mail.
# 
#        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  a  service  on  a
#        non-default  port  as  host:service,  and disable MX (mail
#        exchanger) DNS lookups with [host] or [host]:port. 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 example.com and its subdomains
#        via the uucp transport to the UUCP host named example:
# 
#             example.com      uucp:example
#             .example.com     uucp:example
# 
#        When no nexthop host name is  specified,  the  destination
#        domain  name  is  used instead. For example, the following
#        directs mail for user@example.com via the  slow  transport
#        to  a  mail exchanger for example.com.  The slow transport
#        could be configured to run at most one delivery process at
#        a time:
# 
#             example.com      slow:
# 
#        When no transport is specified, Postfix uses the transport
#        that matches the address  domain  class  (see  DESCRIPTION
#        above).   The following sends all mail for example.com and
#        its subdomains to host gateway.example.com:
# 
#             example.com      :[gateway.example.com]
#             .example.com     :[gateway.example.com]
# 
#        In the above example, the [] suppress  MX  lookups.   This
#        prevents  mail  routing loops when your machine is primary
#        MX host for example.com.
# 
#        In the case of delivery via SMTP, one  may  specify  host-
#        name:service instead of just a host:
# 
#             example.com      smtp:bar.example:2025
# 
#        This directs mail for user@example.com to host bar.example
#        port 2025. Instead of a numerical port a symbolic name may
#        be used. Specify [] around the hostname if MX lookups must
#        be disabled.
# 
#        The error mailer can be used to bounce mail:
# 
#             .example.com     error:mail for *.example.com is  not
#        deliverable
# 
#        This  causes  all mail for user@anything.example.com 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  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).  This feature is not  available  up  to  and
#        including Postfix version 2.2.
# 
#        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.
#        The  text  below  provides  only  a parameter summary. See
#        postconf(5) for more details including examples.
# 
#        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
#        trivial-rewrite(8), rewrite and resolve addresses
#        postconf(5), configuration parameters
#        postmap(1), Postfix lookup table manager
# 
# README FILES
#        Use  "postconf  readme_directory" or "postconf html_direc-
#        tory" to locate this information.
#        DATABASE_README, Postfix lookup table overview
#        FILTER_README, external content filter
# 
# 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)
