postfix-master/master.5.html

   1 <!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
   2         "http://www.w3.org/TR/html4/loose.dtd">
   3 <html> <head>
   4 <meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
   5 <title> Postfix manual - master(5) </title>
   6 </head> <body> <pre>
   7 MASTER(5)                                                            MASTER(5)
   8
   9 <b>NAME</b>
  10        master - Postfix master process configuration file format
  11
  12 <b>DESCRIPTION</b>
  13        The  Postfix mail system is implemented by small number of
  14        (mostly) client commands that are invoked by users, and by
  15        a larger number of services that run in the background.
  16
  17        Postfix  services  are  implemented  by  daemon processes.
  18        These run in the background under control of the <a href="master.8.html"><b>master</b>(8)</a>
  19        process.   The  <a href="master.5.html">master.cf</a> configuration file defines how a
  20        client program connects to a service, and what daemon pro-
  21        gram  runs  when a service is requested.  Most daemon pro-
  22        cesses are short-lived  and  terminate  voluntarily  after
  23        serving  <b><a href="postconf.5.html#max_use">max_use</a></b> clients, or after inactivity for <b><a href="postconf.5.html#max_idle">max_idle</a></b>
  24        or more units of time.
  25
  26        All daemons specified here must speak  a  Postfix-internal
  27        protocol. In order to execute non-Postfix software use the
  28        <a href="local.8.html"><b>local</b>(8)</a>, <a href="pipe.8.html"><b>pipe</b>(8)</a> or <a href="spawn.8.html"><b>spawn</b>(8)</a> services, or run the  server
  29        under control by <b>inetd</b>(8) or equivalent.
  30
  31        After changing <a href="master.5.html">master.cf</a> you must execute "<b>postfix reload</b>"
  32        to reload the configuration.
  33
  34 <b>SYNTAX</b>
  35        The general format of the <a href="master.5.html">master.cf</a> file is as follows:
  36
  37        <b>o</b>      Each logical line defines a single Postfix service.
  38               Each  service is identified by its name and type as
  39               described below.  When multiple lines  specify  the
  40               same  service  name  and type, only the last one is
  41               remembered.  Otherwise, the order of <a href="master.5.html">master.cf</a> ser-
  42               vice definitions does not matter.
  43
  44        <b>o</b>      Empty  lines and whitespace-only lines are ignored,
  45               as are lines whose first  non-whitespace  character
  46               is a `#'.
  47
  48        <b>o</b>      A  logical  line starts with non-whitespace text. A
  49               line that starts with whitespace continues a  logi-
  50               cal line.
  51
  52        Each  logical  line  consists of eight fields separated by
  53        whitespace.  These are described below  in  the  order  as
  54        they appear in the <a href="master.5.html">master.cf</a> file.
  55
  56        Where applicable a field of "-" requests that the built-in
  57        default value be used. For boolean fields specify  "y"  or
  58        "n" to override the default value.
  59
  60        <b>Service name</b>
  61               The service name syntax depends on the service type
  62               as described next.
  63
  64        <b>Service type</b>
  65               Specify one of the following service types:
  66
  67               <b>inet</b>   The service listens on a TCP/IP  socket  and
  68                      is accessible via the network.
  69
  70                      The  service name is specified as <i>host:port</i>,
  71                      denoting the host and port on which new con-
  72                      nections  should  be accepted. The host part
  73                      (and colon) may be omitted.  Either host  or
  74                      port  may be given in symbolic form (host or
  75                      service name) or in numeric form (IP address
  76                      or  port  number).   Host information may be
  77                      enclosed inside "[]", but this form  is  not
  78                      necessary.
  79
  80                      Examples:  a service named <b>127.0.0.1:smtp</b> or
  81                      <b>::1:smtp</b>  receives  mail  via  the  loopback
  82                      interface  only;  and  a service named <b>10025</b>
  83                      accepts connections on TCP  port  10025  via
  84                      all    interfaces    configured   with   the
  85                      <b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a></b> parameter.
  86
  87                      Note: with Postfix  version  2.2  and  later
  88                      specify "<b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = loopback-only</b>" in
  89                      <a href="postconf.5.html">main.cf</a>, instead of hard-coding loopback  IP
  90                      address   information  in  <a href="master.5.html">master.cf</a>  or  in
  91                      <a href="postconf.5.html">main.cf</a>.
  92
  93               <b>unix</b>   The service listens on a UNIX-domain  socket
  94                      and is accessible for local clients only.
  95
  96                      The  service  name is a pathname relative to
  97                      the Postfix queue directory  (pathname  con-
  98                      trolled  with the <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> configura-
  99                      tion parameter in <a href="postconf.5.html">main.cf</a>).
 100
 101                      On Solaris systems the <b>unix</b> type  is  imple-
 102                      mented with streams sockets.
 103
 104               <b>fifo</b>   The  service  listens on a FIFO (named pipe)
 105                      and is accessible for local clients only.
 106
 107                      The service name is a pathname  relative  to
 108                      the  Postfix  queue directory (pathname con-
 109                      trolled with the <b><a href="postconf.5.html#queue_directory">queue_directory</a></b>  configura-
 110                      tion parameter in <a href="postconf.5.html">main.cf</a>).
 111
 112               <b>pass</b>   The service listens on a UNIX-domain socket,
 113                      and is accessible to local clients only.  It
 114                      receives  one open connection (file descrip-
 115                      tor passing) per connection request.
 116
 117                      The service name is a pathname  relative  to
 118                      the  Postfix  queue directory (pathname con-
 119                      trolled with the <b><a href="postconf.5.html#queue_directory">queue_directory</a></b>  configura-
 120                      tion parameter in <a href="postconf.5.html">main.cf</a>).
 121
 122                      This feature is available as of Postfix ver-
 123                      sion 2.5.
 124
 125        <b>Private (default: y)</b>
 126               Whether or not access is  restricted  to  the  mail
 127               system.   Internet  (type  <b>inet</b>)  services can't be
 128               private.
 129
 130        <b>Unprivileged (default: y)</b>
 131               Whether the service runs with root privileges or as
 132               the  owner of the Postfix system (the owner name is
 133               controlled by the <b><a href="postconf.5.html#mail_owner">mail_owner</a></b> configuration variable
 134               in the <a href="postconf.5.html">main.cf</a> file).
 135
 136               The  <a href="local.8.html"><b>local</b>(8)</a>,  <a href="pipe.8.html"><b>pipe</b>(8)</a>,  <a href="spawn.8.html"><b>spawn</b>(8)</a>,  and <a href="virtual.8.html"><b>virtual</b>(8)</a>
 137               daemons require privileges.
 138
 139        <b>Chroot (default: y)</b>
 140               Whether or not the service  runs  chrooted  to  the
 141               mail queue directory (pathname is controlled by the
 142               <b><a href="postconf.5.html#queue_directory">queue_directory</a></b>  configuration  variable   in   the
 143               <a href="postconf.5.html">main.cf</a> file).
 144
 145               Chroot  should  not  be  used  with  the  <a href="local.8.html"><b>local</b>(8)</a>,
 146               <a href="pipe.8.html"><b>pipe</b>(8)</a>,   <a href="spawn.8.html"><b>spawn</b>(8)</a>,   and   <a href="virtual.8.html"><b>virtual</b>(8)</a>    daemons.
 147               Although  the  <a href="proxymap.8.html"><b>proxymap</b>(8)</a> server can run chrooted,
 148               doing so defeats most of the purpose of having that
 149               service in the first place.
 150
 151               The files in the examples/chroot-setup subdirectory
 152               of the Postfix source archive show set up a Postfix
 153               chroot  environment  on  a  variety of systems. See
 154               also <a href="BASIC_CONFIGURATION_README.html">BASIC_CONFIGURATION_README</a> for issues  related
 155               to running daemons chrooted.
 156
 157        <b>Wake up time (default: 0)</b>
 158               Automatically  wake  up the named service after the
 159               specified number of seconds. The wake up is  imple-
 160               mented  by  connecting to the service and sending a
 161               wake up request.  A ? at the  end  of  the  wake-up
 162               time  field requests that no wake up events be sent
 163               before the first time a service is used.  Specify 0
 164               for no automatic wake up.
 165
 166               The <a href="pickup.8.html"><b>pickup</b>(8)</a>, <a href="qmgr.8.html"><b>qmgr</b>(8)</a> and <a href="flush.8.html"><b>flush</b>(8)</a> daemons require
 167               a wake up timer.
 168
 169        <b>Process limit (default: $<a href="postconf.5.html#default_process_limit">default_process_limit</a>)</b>
 170               The maximum number of processes  that  may  execute
 171               this  service  simultaneously.  Specify  0  for  no
 172               process count limit.
 173
 174               NOTE: Some Postfix services must be configured as a
 175               single-process  service  (for example, <a href="qmgr.8.html"><b>qmgr</b>(8)</a>) and
 176               some services must be configured  with  no  process
 177               limit (for example, <a href="cleanup.8.html"><b>cleanup</b>(8)</a>).  These limits must
 178               not be changed.
 179
 180        <b>Command name + arguments</b>
 181               The command to be executed.   Characters  that  are
 182               special  to  the  shell  such as "&gt;" or "|" have no
 183               special meaning here, and quotes cannot be used  to
 184               protect arguments containing whitespace.
 185
 186               The  command name is relative to the Postfix daemon
 187               directory  (pathname  is  controlled  by  the  <b><a href="postconf.5.html#daemon_directory">dae</a>-</b>
 188               <b><a href="postconf.5.html#daemon_directory">mon_directory</a></b> configuration variable).
 189
 190               The  command  argument syntax for specific commands
 191               is specified in the respective daemon manual  page.
 192
 193               The  following  command-line  options have the same
 194               effect for all daemon programs:
 195
 196               <b>-D</b>     Run the daemon under control by the  command
 197                      specified with the <b><a href="postconf.5.html#debugger_command">debugger_command</a></b> variable
 198                      in  the  <a href="postconf.5.html">main.cf</a>  configuration  file.   See
 199                      <a href="DEBUG_README.html">DEBUG_README</a> for hints and tips.
 200
 201               <b>-o</b> <i>name</i>=<i>value</i>
 202                      Override  the  named  <a href="postconf.5.html">main.cf</a>  configuration
 203                      parameter. The parameter value can refer  to
 204                      other parameters as <i>$name</i> etc., just like in
 205                      <a href="postconf.5.html">main.cf</a>.  See <a href="postconf.5.html"><b>postconf</b>(5)</a> for syntax.
 206
 207                      NOTE 1: do not specify whitespace around the
 208                      "=".   In  parameter  values,  either  avoid
 209                      whitespace altogether, use commas instead of
 210                      spaces,   or  consider  overrides  like  "-o
 211                      name=$override_parameter"    with     $over-
 212                      ride_parameter set in <a href="postconf.5.html">main.cf</a>.
 213
 214                      NOTE  2: Over-zealous use of parameter over-
 215                      rides makes the Postfix  configuration  hard
 216                      to  understand  and  maintain.  At a certain
 217                      point, it might be easier to configure  mul-
 218                      tiple  instances of Postfix, instead of con-
 219                      figuring  multiple  personalities  via  mas-
 220                      ter.cf.
 221
 222               <b>-v</b>     Increase  the verbose logging level. Specify
 223                      multiple <b>-v</b> options to make a Postfix daemon
 224                      process increasingly verbose.
 225
 226 <b>SEE ALSO</b>
 227        <a href="master.8.html">master(8)</a>, process manager
 228        <a href="postconf.5.html">postconf(5)</a>, configuration parameters
 229
 230 <b>README FILES</b>
 231        <a href="BASIC_CONFIGURATION_README.html">BASIC_CONFIGURATION_README</a>, basic configuration
 232        <a href="DEBUG_README.html">DEBUG_README</a>, Postfix debugging
 233
 234 <b>LICENSE</b>
 235        The Secure Mailer license must be  distributed  with  this
 236        software.
 237
 238 <b>AUTHOR(S)</b>
 239        Initial version by
 240        Magnus Baeck
 241        Lund Institute of Technology
 242        Sweden
 243
 244        Wietse Venema
 245        IBM T.J. Watson Research
 246        P.O. Box 704
 247        Yorktown Heights, NY 10598, USA
 248
 249                                                                      MASTER(5)
 250 </pre> </body> </html>