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MASTER(5)		      File Formats Manual		     MASTER(5)

NAME
       master -	Postfix	master process configuration file format

DESCRIPTION
       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 master.cf  con-
       figuration file defines how a client program connects to	a service, and
       what daemon program runs	when a service is requested.  Most daemon pro-
       cesses  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	master.cf  you must execute "postfix reload" to	reload
       the configuration.

SYNTAX
       The general format of the master.cf file	is as follows:

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

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

       o      Each logical line	defines	a single Postfix service.   Each  ser-
	      vice  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 master.cf
	      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 master.cf
       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  127.0.0.1:smtp  or  ::1:smtp
		     receives mail via the loopback interface only; and	a ser-
		     vice named	10025 accepts connections on  TCP  port	 10025
		     via  all  interfaces  configured with the inet_interfaces
		     parameter.

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

	      unix   The service listens on a UNIX-domain socket and is	acces-
		     sible 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	main.cf).

		     On	Solaris	8 and earlier systems the unix type is	imple-
		     mented with streams sockets.

	      fifo   The  service listens on a FIFO (named pipe) and is	acces-
		     sible 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	main.cf).

	      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	main.cf).

		     On	 Solaris 8 and earlier systems the pass	type is	imple-
		     mented with streams sockets.

		     This feature is available as of Postfix version 2.5.

       Private (default: y)
	      Whether or not access is restricted to the mail system.	Inter-
	      net (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 main.cf file).

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

       Chroot (default:	y)
	      Whether or not the service  runs	chrooted  to  the  mail	 queue
	      directory	(pathname is controlled	by the queue_directory config-
	      uration variable in the main.cf 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 Post-
	      fix 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 num-
	      ber  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 auto-
	      matic 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	white-
	      space.

	      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 main.cf config-
		     uration file.  See	DEBUG_README for hints and tips.

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

		     NOTE  1:  do  not specify whitespace around the "=" or in
		     parameter values. To specify a parameter value that  con-
		     tains  whitespace,	use commas instead of spaces, or spec-
		     ify the value in main.cf. Example:

		     /usr/local/etc/postfix/master.cf:
			 submission inet .... smtpd
			     -o	smtpd_mumble=$submission_mumble

		     /usr/local/etc/postfix/main.cf
			 submission_mumble = text with whitespace...

		     NOTE 2: 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  mul-
		     tiple instances of	Postfix, instead of configuring	multi-
		     ple personalities via master.cf.

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

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

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

LICENSE
       The Secure Mailer license must be distributed with this software.

AUTHOR(S)
       Initial version by
       Magnus Baeck
       Lund Institute of Technology
       Sweden

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

								     MASTER(5)

NAME | DESCRIPTION | SYNTAX | SEE ALSO | README FILES | LICENSE | AUTHOR(S)

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