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=utf-8"> 5<title> Postfix manual - master(5) </title> 6</head> <body> <pre> 7MASTER(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 (mostly) 14 client commands that are invoked by users, and by a larger number of 15 services that run in the background. 16 17 Postfix services are implemented by daemon processes. These run in the 18 background, started on-demand by the <a href="master.8.html"><b>master</b>(8)</a> process. The <a href="master.5.html">master.cf</a> 19 configuration file defines how a client program connects to a service, 20 and what daemon program runs when a service is requested. Most daemon 21 processes are short-lived and terminate voluntarily after serving 22 <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> or more units of 23 time. 24 25 All daemons specified here must speak a Postfix-internal protocol. In 26 order to execute non-Postfix software use the <a href="local.8.html"><b>local</b>(8)</a>, <a href="pipe.8.html"><b>pipe</b>(8)</a> or 27 <a href="spawn.8.html"><b>spawn</b>(8)</a> services, or execute the software with <b>inetd</b>(8) or equivalent. 28 29 After changing <a href="master.5.html">master.cf</a> you must execute "<b>postfix reload</b>" to reload 30 the configuration. 31 32<b>SYNTAX</b> 33 The general format of the <a href="master.5.html">master.cf</a> file is as follows: 34 35 <b>o</b> Empty lines and whitespace-only lines are ignored, as are lines 36 whose first non-whitespace character is a `#'. 37 38 <b>o</b> A logical line starts with non-whitespace text. A line that 39 starts with whitespace continues a logical line. 40 41 <b>o</b> Each logical line defines a single Postfix service. Each ser- 42 vice is identified by its name and type as described below. 43 When multiple lines specify the same service name and type, only 44 the last one is remembered. Otherwise, the order of <a href="master.5.html">master.cf</a> 45 service definitions does not matter. 46 47 Each logical line consists of eight fields separated by whitespace. 48 These are described below in the order as they appear in the <a href="master.5.html">master.cf</a> 49 file. 50 51 Where applicable a field of "-" requests that the built-in default 52 value be used. For boolean fields specify "y" or "n" to override the 53 default value. 54 55 <b>Service name</b> 56 The service name syntax depends on the service type as described 57 next. 58 59 <b>Service type</b> 60 Specify one of the following service types: 61 62 <b>inet</b> The service listens on a TCP/IP socket and is accessible 63 via the network. 64 65 The service name is specified as <i>host:port</i>, denoting the 66 host and port on which new connections should be 67 accepted. The host part (and colon) may be omitted. 68 Either host or port may be given in symbolic form (see 69 <b>hosts</b>(5) or <b>services</b>(5)) or in numeric form (IP address 70 or port number). Host information may be enclosed inside 71 "[]"; this form is necessary only with IPv6 addresses. 72 73 Examples: a service named <b>127.0.0.1:smtp</b> or <b>::1:smtp</b> 74 receives mail via the loopback interface only; and a ser- 75 vice named <b>10025</b> accepts connections on TCP port 10025 76 via all interfaces configured with the <b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a></b> 77 parameter. 78 79 Note: with Postfix version 2.2 and later specify 80 "<b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = loopback-only</b>" in <a href="postconf.5.html">main.cf</a>, instead of 81 hard-coding loopback IP address information in <a href="master.5.html">master.cf</a> 82 or in <a href="postconf.5.html">main.cf</a>. 83 84 <b>unix</b> The service listens on a UNIX-domain stream socket and is 85 accessible for local clients only. 86 87 The service name is a pathname relative to the Postfix 88 queue directory (pathname controlled with the 89 <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> configuration parameter in <a href="postconf.5.html">main.cf</a>). 90 91 On Solaris 8 and earlier systems the <b>unix</b> type is imple- 92 mented with streams sockets. 93 94 <b>unix-dgram</b> 95 The service listens on a UNIX-domain datagram socket and 96 is accessible for local clients only. 97 98 The service name is a pathname relative to the Postfix 99 queue directory (pathname controlled with the 100 <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> configuration parameter in <a href="postconf.5.html">main.cf</a>). 101 102 <b>fifo</b> (obsolete) 103 The service listens on a FIFO (named pipe) and is acces- 104 sible for local clients only. 105 106 The service name is a pathname relative to the Postfix 107 queue directory (pathname controlled with the 108 <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> configuration parameter in <a href="postconf.5.html">main.cf</a>). 109 110 <b>pass</b> The service listens on a UNIX-domain stream socket, and 111 is accessible to local clients only. It receives one open 112 connection (file descriptor passing) per connection 113 request. 114 115 The service name is a pathname relative to the Postfix 116 queue directory (pathname controlled with the 117 <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> configuration parameter in <a href="postconf.5.html">main.cf</a>). 118 119 On Solaris 8 and earlier systems the <b>pass</b> type is imple- 120 mented with streams sockets. 121 122 This feature is available as of Postfix version 2.5. 123 124 <b>Private (default: y)</b> 125 Whether a service is internal to Postfix (pathname starts with 126 <b>private/</b>), or exposed through Postfix command-line tools (path- 127 name starts with <b>public/</b>). Internet (type <b>inet</b>) services can't 128 be private. 129 130 <b>Unprivileged (default: y)</b> 131 Whether the service runs with root privileges or as the owner of 132 the Postfix system (the owner name is controlled by the 133 <b><a href="postconf.5.html#mail_owner">mail_owner</a></b> configuration variable in the <a href="postconf.5.html">main.cf</a> file). 134 135 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> daemons require 136 privileges. 137 138 <b>Chroot (default: Postfix</b> ><b>= 3.0: n, Postfix</b> < <b>3.0: y)</b> 139 Whether or not the service runs chrooted to the mail queue 140 directory (pathname is controlled by the <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> config- 141 uration variable in the <a href="postconf.5.html">main.cf</a> file). 142 143 Chroot should not be used with 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>, 144 and <a href="virtual.8.html"><b>virtual</b>(8)</a> daemons. Although the <a href="proxymap.8.html"><b>proxymap</b>(8)</a> server can run 145 chrooted, doing so defeats most of the purpose of having that 146 service in the first place. 147 148 The files in the examples/chroot-setup subdirectory of the Post- 149 fix source show how to set up a Postfix chroot environment on a 150 variety of systems. See also <a href="BASIC_CONFIGURATION_README.html">BASIC_CONFIGURATION_README</a> for 151 issues related to running daemons chrooted. 152 153 <b>Wake up time (default: 0)</b> 154 Automatically wake up the named service after the specified num- 155 ber of seconds. The wake up is implemented by connecting to the 156 service and sending a wake up request. A ? at the end of the 157 wake-up time field requests that no wake up events be sent 158 before the first time a service is used. Specify 0 for no auto- 159 matic wake up. 160 161 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 a wake up 162 timer. 163 164 <b>Process limit (default: $<a href="postconf.5.html#default_process_limit">default_process_limit</a>)</b> 165 The maximum number of processes that may execute this service 166 simultaneously. Specify 0 for no process count limit. 167 168 NOTE: Some Postfix services must be configured as a sin- 169 gle-process service (for example, <a href="qmgr.8.html"><b>qmgr</b>(8)</a>) and some services 170 must be configured with no process limit (for example, 171 <a href="cleanup.8.html"><b>cleanup</b>(8)</a>). These limits must not be changed. 172 173 <b>Command name + arguments</b> 174 The command to be executed. Characters that are special to the 175 shell such as ">" or "|" have no special meaning here, and 176 quotes cannot be used to protect arguments containing white- 177 space. To protect whitespace, use "{" and "}" as described 178 below. 179 180 The command name is relative to the Postfix daemon directory 181 (pathname is controlled by the <b><a href="postconf.5.html#daemon_directory">daemon_directory</a></b> configuration 182 variable). 183 184 The command argument syntax for specific commands is specified 185 in the respective daemon manual page. 186 187 The following command-line options have the same effect for all 188 daemon programs: 189 190 <b>-D</b> Run the daemon under control by the command specified 191 with the <b><a href="postconf.5.html#debugger_command">debugger_command</a></b> variable in the <a href="postconf.5.html">main.cf</a> config- 192 uration file. See <a href="DEBUG_README.html">DEBUG_README</a> for hints and tips. 193 194 <b>-o {</b> <i>name</i> = <i>value</i> <b>}</b> (long form, Postfix >= 3.0) 195 196 <b>-o</b> <i>name</i>=<i>value</i> (short form) 197 Override the named <a href="postconf.5.html">main.cf</a> configuration parameter. The 198 parameter value can refer to other parameters as <i>$name</i> 199 etc., just like in <a href="postconf.5.html">main.cf</a>. See <a href="postconf.5.html"><b>postconf</b>(5)</a> for syntax. 200 201 NOTE 1: With the "long form" shown above, whitespace 202 after "{", around "=", and before "}" is ignored, and 203 whitespace within the parameter value is preserved. 204 205 NOTE 2: with the "short form" shown above, do not specify 206 whitespace around the "=" or in parameter values. To 207 specify a parameter value that contains whitespace, use 208 the long form described above, or use commas instead of 209 spaces, or specify the value in <a href="postconf.5.html">main.cf</a>. Example: 210 211 /etc/postfix/<a href="master.5.html">master.cf</a>: 212 submission inet .... smtpd 213 -o smtpd_xxx_yyy=$submission_xxx_yyy 214 215 /etc/postfix/<a href="postconf.5.html">main.cf</a> 216 submission_xxx_yyy = text with whitespace... 217 218 NOTE 3: Over-zealous use of parameter overrides makes the 219 Postfix configuration hard to understand and maintain. 220 At a certain point, it might be easier to configure mul- 221 tiple instances of Postfix, instead of configuring multi- 222 ple personalities via <a href="master.5.html">master.cf</a>. 223 224 <b>-v</b> Increase the verbose logging level. Specify multiple <b>-v</b> 225 options to make a Postfix daemon process increasingly 226 verbose. 227 228 Other command-line arguments 229 Specify "{" and "}" around command arguments that contain 230 whitespace (Postfix 3.0 and later). Whitespace after "{" 231 and before "}" is ignored. 232 233<b>SEE ALSO</b> 234 <a href="master.8.html">master(8)</a>, process manager 235 <a href="postconf.5.html">postconf(5)</a>, configuration parameters 236 237<b>README FILES</b> 238 <a href="BASIC_CONFIGURATION_README.html">BASIC_CONFIGURATION_README</a>, basic configuration 239 <a href="DEBUG_README.html">DEBUG_README</a>, Postfix debugging 240 241<b>LICENSE</b> 242 The Secure Mailer license must be distributed with this software. 243 244<b>AUTHOR(S)</b> 245 Initial version by 246 Magnus Baeck 247 Lund Institute of Technology 248 Sweden 249 250 Wietse Venema 251 IBM T.J. Watson Research 252 P.O. Box 704 253 Yorktown Heights, NY 10598, USA 254 255 Wietse Venema 256 Google, Inc. 257 111 8th Avenue 258 New York, NY 10011, USA 259 260 MASTER(5) 261</pre> </body> </html> 262