# TRANSPORT(5)                                                      TRANSPORT(5)
# 
# NAME
#        transport - Postfix transport table format
# 
# SYNOPSIS
#        postmap /etc/postfix/transport
# 
#        postmap -q "string" /etc/postfix/transport
# 
#        postmap -q - /etc/postfix/transport <inputfile
# 
# DESCRIPTION
#        The  optional  transport(5) table specifies a mapping from
#        email addresses to message delivery transports  and  next-
#        hop  destinations.   Message  delivery  transports such as
#        local or smtp are defined in the master.cf file, and next-
#        hop  destinations are typically hosts or domain names. The
#        table is searched by the trivial-rewrite(8) daemon.
# 
#        This  mapping  overrides  the  default   transport:nexthop
#        selection that is built into Postfix:
# 
#        local_transport (default: local:$myhostname)
#               This  is  the default for final delivery to domains
#               listed with mydestination, and for [ipaddress] des-
#               tinations    that    match    $inet_interfaces   or
#               $proxy_interfaces. The default nexthop  destination
#               is the MTA hostname.
# 
#        virtual_transport (default: virtual:)
#               This  is  the default for final delivery to domains
#               listed with  virtual_mailbox_domains.  The  default
#               nexthop destination is the recipient domain.
# 
#        relay_transport (default: relay:)
#               This  is the default for remote delivery to domains
#               listed with relay_domains. In order  of  decreasing
#               precedence,  the  nexthop destination is taken from
#               relay_transport,   sender_dependent_relayhost_maps,
#               relayhost, or from the recipient domain.
# 
#        default_transport (default: smtp:)
#               This  is  the  default for remote delivery to other
#               destinations.  In order of  decreasing  precedence,
#               the    nexthop    destination    is    taken   from
#               default_transport, sender_dependent_relayhost_maps,
#               relayhost, or from the recipient domain.
# 
#        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  /etc/postfix/transport"  to  rebuild  an indexed
#        file after changing the corresponding 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
#        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 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.
# 
#        * transport:nexthop
#               The special pattern * represents any address  (i.e.
#               it  functions  as  the  wild-card  pattern,  and is
#               unique to Postfix transport tables).
# 
#        Note 1:  the  null  recipient  address  is  looked  up  as
#        $empty_address_recipient@$myhostname (default: mailer-dae-
#        mon@hostname).
# 
#        Note 2: 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 ta-
#        ble, until a pattern is  found  that  matches  the  search
#        string.
# 
#        The trivial-rewrite(8) server disallows regular expression
#        substitution of  $1  etc.  in  regular  expression  lookup
#        tables,  because  that could open a security hole (Postfix
#        version 2.3 and later).
# 
# 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  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
#        master(5), master.cf file format
#        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.
#        ADDRESS_REWRITING_README, address rewriting guide
#        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)
