postfix.ORG

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transport - Postfix transport table format  SYNOPSIS        postmap /etc/postfix/transport         postmap -q "string" /etc/postfix/transport         postmap -q - /etc/postfix/transport <inputfileDESCRIPTION        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]  destinations  that  match               $inet_interfaces or $proxy_interfaces. The default nexthop  des-               tination 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_depen-               dent_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        sender_dependent_default_transport_maps,               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  expressions,  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 logical 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 nex-               thop.         user@domain transport:nexthop               Deliver mail for user@domain through transport to nexthop.         domain transport:nexthop               Deliver mail for domain through transport to nexthop.         .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  parent_domain_matches_subdomains  configuration               setting.  Otherwise, a domain name matches itself and its subdo-               mains.         * 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-daemon@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  mas-        ter.cf file).         The  nexthop  field usually specifies one recipient domain or hostname.        In the case of the Postfix SMTP/LMTP client, the nexthop field may con-        tain  a  list  of nexthop destinations separated by comma or whitespace        (Postfix 3.5 and later).         The syntax of a nexthop destination is transport dependent.  With 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 field means "do not change": use the        delivery transport and nexthop information 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 transport or the nexthop information) and spec-        ify 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@exam-        ple.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.exam-        ple.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 or LMTP, one may specify host: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.         Deliveries via SMTP or LMTP support multiple destinations  (Postfix  >=        3.5):              example.com      smtp:bar.example, foo.example         This  tries  to  deliver  to  bar.example  before  trying to deliver to        foo.example.         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.         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  description  of  the  TCP        client/server lookup protocol, see tcp_table(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 (MAILER-DAEMON)               The recipient of mail addressed to the null address.         parent_domain_matches_subdomains (see 'postconf -d' output)               A  list of Postfix features where the pattern "example.com" also               matches subdomains  of  example.com,  instead  of  requiring  an               explicit ".example.com" pattern.         transport_maps (empty)               Optional  lookup  tables with mappings from recipient address to               (message delivery transport, next-hop destination).

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