TRANSPORT(5)                                         TRANSPORT(5)


NAME
       transport - format of Postfix transport table

SYNOPSIS
       postmap /etc/postfix/transport

DESCRIPTION
       The  optional  transport  file  specifies  a  mapping from
       domain hierarchies to message delivery  transports  and/or
       relay hosts. The mapping is used by the trivial-rewrite(8)
       daemon.

       The file 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.  After  updating  this
       table, issue the postfix reload command to make the change
       visible.

       The format of the transport table is as follows:

       blanks and comments
              Blank lines are ignored,  as  are  lines  beginning
              with `#'.

       domain transport:nexthop
              Mail  for  domain,  and  any  subdomain thereof, is
              delivered through transport to nexthop.

              The interpretation of the nexthop field  is  trans-
              port  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  can  also  be
              used with IP addresses instead of hostnames.

EXAMPLES
       In order to send mail for user@foo.org via the uucp trans-
       port to the UUCP host named 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, the default transport is
       used, as specified via the default_transport configuration
       parameter.  The  following sends all mail for user@foo.org
       to host bar.org:



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TRANSPORT(5)                                         TRANSPORT(5)


            foo.org      :bar.org

       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 destination in order to dis-
       able MX 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.

       transport_maps
              List of transport lookup tables.

       Other parameters of interest:

       default_transport
              The  transport  to use when no transport is explic-
              itly specified.

       relayhost
              The default host to send to when no transport table
              entry matches.

SEE ALSO
       postmap(1) create mapping table
       trivial-rewrite(8) rewrite and resolve addresses

LICENSE
       See  the  Postfix  LICENSE, which must be distributed with
       this software.

AUTHOR(S)
       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA













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