Provided by: postfix_3.1.0-3ubuntu0.4_amd64 bug


       master - Postfix master process configuration file format


       The  Postfix  mail  system is implemented by small number of (mostly) client commands that
       are invoked by users, and by a larger number of services that run in the background.

       Postfix services are implemented by daemon processes. These run in  the  background  under
       control  of  the master(8) process.  The configuration file defines how a client
       program connects to a service, and what daemon program runs when a service  is  requested.
       Most  daemon  processes  are  short-lived  and terminate voluntarily after serving max_use
       clients, or after inactivity for max_idle or more units of time.

       All daemons specified here must speak a Postfix-internal protocol.  In  order  to  execute
       non-Postfix  software  use  the  local(8), pipe(8) or spawn(8) services, or run the server
       under control by inetd(8) or equivalent.

       After changing you must execute "postfix reload" to reload the configuration.


       The general format of the file is as follows:

       •      Empty lines and whitespace-only  lines  are  ignored,  as  are  lines  whose  first
              non-whitespace character is a `#'.

       •      A  logical line starts with non-whitespace text. A line that starts with whitespace
              continues a logical line.

       •      Each logical line defines a single Postfix service.  Each service is identified  by
              its name and type as described below.  When multiple lines specify the same service
              name and type, only the last one is remembered.  Otherwise, the order of
              service definitions does not matter.

       Each  logical  line consists of eight fields separated by whitespace.  These are described
       below in the order as they appear in the file.

       Where applicable a field of "-" requests that the built-in  default  value  be  used.  For
       boolean fields specify "y" or "n" to override the default value.

       Service name
              The service name syntax depends on the service type as described next.

       Service type
              Specify one of the following service types:

              inet   The service listens on a TCP/IP socket and is accessible via the network.

                     The  service  name  is specified as host:port, denoting the host and port on
                     which new connections should be accepted. The host part (and colon)  may  be
                     omitted.  Either host or port may be given in symbolic form (host or service
                     name) or in numeric form (IP address or port number).  Host information  may
                     be enclosed inside "[]"; this form is necessary only with IPv6 addresses.

                     Examples:  a  service named or ::1:smtp receives mail via the
                     loopback interface only; and a service named 10025  accepts  connections  on
                     TCP  port  10025  via  all  interfaces  configured  with the inet_interfaces

                     Note:  with  Postfix  version  2.2  and  later  specify  "inet_interfaces  =
                     loopback-only"  in,  instead  of  hard-coding  loopback  IP address
                     information in or in

              unix   The service listens on a UNIX-domain socket  and  is  accessible  for  local
                     clients only.

                     The  service  name  is  a  pathname  relative to the Postfix queue directory
                     (pathname controlled with the  queue_directory  configuration  parameter  in

                     On  Solaris  8 and earlier systems the unix type is implemented with streams

              fifo   The service listens on a FIFO (named  pipe)  and  is  accessible  for  local
                     clients only.

                     The  service  name  is  a  pathname  relative to the Postfix queue directory
                     (pathname controlled with the  queue_directory  configuration  parameter  in

              pass   The  service  listens  on  a  UNIX-domain socket, and is accessible to local
                     clients only. It receives one open connection (file descriptor passing)  per
                     connection request.

                     The  service  name  is  a  pathname  relative to the Postfix queue directory
                     (pathname controlled with the  queue_directory  configuration  parameter  in

                     On  Solaris  8 and earlier systems the pass type is implemented with streams

                     This feature is available as of Postfix version 2.5.

       Private (default: y)
              Whether or not access is restricted to  the  mail  system.   Internet  (type  inet)
              services can't be private.

       Unprivileged (default: y)
              Whether the service runs with root privileges or as the owner of the Postfix system
              (the owner name is controlled by  the  mail_owner  configuration  variable  in  the

              The local(8), pipe(8), spawn(8), and virtual(8) daemons require privileges.

       Chroot (default: Postfix >= 3.0: n, Postfix <3.0: y)
              Whether  or  not the service runs chrooted to the mail queue directory (pathname is
              controlled by the queue_directory configuration variable in the file).

              Chroot should not be used with the  local(8),  pipe(8),  spawn(8),  and  virtual(8)
              daemons.   Although  the proxymap(8) server can run chrooted, doing so defeats most
              of the purpose of having that service in the first place.

              The files in the examples/chroot-setup subdirectory of the Postfix  source  archive
              show  set  up  a  Postfix  chroot  environment  on  a  variety of systems. See also
              BASIC_CONFIGURATION_README for issues related to running daemons chrooted.

       Wake up time (default: 0)
              Automatically wake up the named service after the specified number of seconds.  The
              wake  up is implemented by connecting to the service and sending a wake up request.
              A ? at the end of the wake-up time field requests that no wake up  events  be  sent
              before the first time a service is used.  Specify 0 for no automatic wake up.

              The pickup(8), qmgr(8) and flush(8) daemons require a wake up timer.

       Process limit (default: $default_process_limit)
              The  maximum  number  of  processes  that  may execute this service simultaneously.
              Specify 0 for no process count limit.

              NOTE: Some Postfix services must be configured as  a  single-process  service  (for
              example,  qmgr(8))  and some services must be configured with no process limit (for
              example, cleanup(8)).  These limits must not be changed.

       Command name + arguments
              The command to be executed.  Characters that are special to the shell such  as  ">"
              or "|" have no special meaning here, and quotes cannot be used to protect arguments
              containing whitespace. To protect whitespace, use "{" and "}" as described below.

              The command  name  is  relative  to  the  Postfix  daemon  directory  (pathname  is
              controlled by the daemon_directory configuration variable).

              The  command  argument  syntax for specific commands is specified in the respective
              daemon manual page.

              The following command-line options have the same effect for all daemon programs:

              -D     Run  the  daemon  under  control  by  the   command   specified   with   the
                     debugger_command   variable   in   the  configuration  file.   See
                     DEBUG_README for hints and tips.

              -o { name = value } (long form, Postfix >= 3.0)

              -o name=value (short form)
                     Override the named configuration parameter. The parameter value  can
                     refer  to  other  parameters  as  $name  etc.,  just  like  in  See
                     postconf(5) for syntax.

                     NOTE 1: With the "long form" shown above, whitespace after "{", around  "=",
                     and  before  "}"  is  ignored,  and whitespace within the parameter value is

                     NOTE 2: with the "short form" shown above, do not specify whitespace  around
                     the  "="  or in parameter values. To specify a parameter value that contains
                     whitespace, use the long form described above,  or  use  commas  instead  of
                     spaces, or specify the value in Example:

                         submission inet .... smtpd
                             -o smtpd_xxx_yyy=$submission_xxx_yyy

                         submission_xxx_yyy = text with whitespace...

                     NOTE   3:   Over-zealous  use  of  parameter  overrides  makes  the  Postfix
                     configuration hard to understand and maintain.  At a certain point, it might
                     be easier to configure multiple instances of Postfix, instead of configuring
                     multiple personalities via

              -v     Increase the verbose logging level. Specify multiple -v options  to  make  a
                     Postfix daemon process increasingly verbose.

              Other command-line arguments
                     Specify  "{"  and  "}"  around  command  arguments  that  contain whitespace
                     (Postfix 3.0 and later). Whitespace after "{" and before "}" is ignored.


       master(8), process manager
       postconf(5), configuration parameters


       Use "postconf readme_directory" or "postconf html_directory" to locate this information.
       BASIC_CONFIGURATION_README, basic configuration
       DEBUG_README, Postfix debugging


       The Secure Mailer license must be distributed with this software.


       Initial version by
       Magnus Baeck
       Lund Institute of Technology

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

       Wietse Venema
       Google, Inc.
       111 8th Avenue
       New York, NY 10011, USA