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<link rel='stylesheet' type='text/css' href='postfix-doc.css'> 6<title> Postfix manual - master(5) </title> 7</head> <body> <pre> 8MASTER(5) MASTER(5) 9 10<b>NAME</b> 11 master - Postfix master process configuration file format 12 13<b>DESCRIPTION</b> 14 The Postfix mail system is implemented by small number of (mostly) 15 client commands that are invoked by users, and by a larger number of 16 services that run in the background. 17 18 Postfix services are implemented by daemon processes. These run in the 19 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> 20 configuration file defines how a client program connects to a service, 21 and what daemon program runs when a service is requested. Most daemon 22 processes are short-lived and terminate voluntarily after serving 23 <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 24 time. 25 26 All daemons specified here must speak a Postfix-internal protocol. In 27 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 28 <a href="spawn.8.html"><b>spawn</b>(8)</a> services, or execute the software with <b>inetd</b>(8) or equivalent. 29 30 After changing <a href="master.5.html">master.cf</a> you must execute "<b>postfix reload</b>" to reload 31 the configuration. 32 33<b>SYNTAX</b> 34 The general format of the <a href="master.5.html">master.cf</a> file is as follows: 35 36 <b>o</b> Empty lines and whitespace-only lines are ignored, as are lines 37 whose first non-whitespace character is a `#'. 38 39 <b>o</b> A logical line starts with non-whitespace text. A line that 40 starts with whitespace continues a logical line. 41 42 <b>o</b> Each logical line defines a single Postfix service. Each ser- 43 vice is identified by its name and type as described below. 44 When multiple lines specify the same service name and type, only 45 the last one is remembered. Otherwise, the order of <a href="master.5.html">master.cf</a> 46 service definitions does not matter. 47 48 Each logical line consists of eight fields separated by whitespace. 49 These are described below in the order as they appear in the <a href="master.5.html">master.cf</a> 50 file. 51 52 Where applicable a field of "-" requests that the built-in default 53 value be used. For boolean fields specify "y" or "n" to override the 54 default value. 55 56 <b>Service name</b> 57 The service name syntax depends on the service type as described 58 next. 59 60 <b>Service type</b> 61 Specify one of the following service types: 62 63 <b>inet</b> The service listens on a TCP/IP socket and is accessible 64 via the network. 65 66 The service name is specified as <i>host:port</i>, denoting the 67 host and port on which new connections should be 68 accepted. The host part (and colon) may be omitted. 69 Either host or port may be given in symbolic form (see 70 <b>hosts</b>(5) or <b>services</b>(5)) or in numeric form (IP address 71 or port number). Host information may be enclosed inside 72 "[]"; this form is necessary only with IPv6 addresses. 73 74 Examples: a service named <b>127.0.0.1:smtp</b> or <b>::1:smtp</b> 75 receives mail via the loopback interface only; and a ser- 76 vice named <b>10025</b> accepts connections on TCP port 10025 77 via all interfaces configured with the <b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a></b> 78 parameter. 79 80 Note: with Postfix version 2.2 and later specify 81 "<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 82 hard-coding loopback IP address information in <a href="master.5.html">master.cf</a> 83 or in <a href="postconf.5.html">main.cf</a>. 84 85 <b>unix</b> The service listens on a UNIX-domain stream socket and is 86 accessible for local clients only. 87 88 The service name is a pathname relative to the Postfix 89 queue directory (pathname controlled with the 90 <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> configuration parameter in <a href="postconf.5.html">main.cf</a>). 91 92 On Solaris 8 and earlier systems the <b>unix</b> type is imple- 93 mented with streams sockets. 94 95 <b>unix-dgram</b> 96 The service listens on a UNIX-domain datagram socket and 97 is accessible for local clients only. 98 99 The service name is a pathname relative to the Postfix 100 queue directory (pathname controlled with the 101 <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> configuration parameter in <a href="postconf.5.html">main.cf</a>). 102 103 <b>fifo</b> (obsolete) 104 The service listens on a FIFO (named pipe) and is acces- 105 sible for local clients only. 106 107 The service name is a pathname relative to the Postfix 108 queue directory (pathname controlled with the 109 <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> configuration parameter in <a href="postconf.5.html">main.cf</a>). 110 111 <b>pass</b> The service listens on a UNIX-domain stream socket, and 112 is accessible to local clients only. It receives one open 113 connection (file descriptor passing) per connection 114 request. 115 116 The service name is a pathname relative to the Postfix 117 queue directory (pathname controlled with the 118 <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> configuration parameter in <a href="postconf.5.html">main.cf</a>). 119 120 On Solaris 8 and earlier systems the <b>pass</b> type is imple- 121 mented with streams sockets. 122 123 This feature is available as of Postfix version 2.5. 124 125 <b>Private (default: y)</b> 126 Whether a service is internal to Postfix (pathname starts with 127 <b>private/</b>), or exposed through Postfix command-line tools (path- 128 name starts with <b>public/</b>). Internet (type <b>inet</b>) services can't 129 be private. 130 131 <b>Unprivileged (default: y)</b> 132 Whether the service runs with root privileges or as the owner of 133 the Postfix system (the owner name is controlled by the 134 <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). 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> daemons require 137 privileges. 138 139 <b>Chroot (default: Postfix</b> ><b>= 3.0: n, Postfix</b> < <b>3.0: y)</b> 140 Whether or not the service runs chrooted to the mail queue 141 directory (pathname is controlled by the <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> config- 142 uration variable in the <a href="postconf.5.html">main.cf</a> file). 143 144 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>, 145 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 146 chrooted, doing so defeats most of the purpose of having that 147 service in the first place. 148 149 The files in the examples/chroot-setup subdirectory of the Post- 150 fix source show how to set up a Postfix chroot environment on a 151 variety of systems. See also <a href="BASIC_CONFIGURATION_README.html">BASIC_CONFIGURATION_README</a> for 152 issues related to running daemons chrooted. 153 154 <b>Wake up time (default: 0)</b> 155 Automatically wake up the named service after the specified num- 156 ber of seconds. The wake up is implemented by connecting to the 157 service and sending a wake up request. A ? at the end of the 158 wake-up time field requests that no wake up events be sent 159 before the first time a service is used. Specify 0 for no auto- 160 matic wake up. 161 162 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 163 timer. 164 165 <b>Process limit (default: $<a href="postconf.5.html#default_process_limit">default_process_limit</a>)</b> 166 The maximum number of processes that may execute this service 167 simultaneously. Specify 0 for no process count limit. 168 169 NOTE: Some Postfix services must be configured as a sin- 170 gle-process service (for example, <a href="qmgr.8.html"><b>qmgr</b>(8)</a>) and some services 171 must be configured with no process limit (for example, 172 <a href="cleanup.8.html"><b>cleanup</b>(8)</a>). These limits must not be changed. 173 174 <b>Command name + arguments</b> 175 The command to be executed. Characters that are special to the 176 shell such as ">" or "|" have no special meaning here, and 177 quotes cannot be used to protect arguments containing white- 178 space. To protect whitespace, use "{" and "}" as described 179 below. 180 181 The command name is relative to the Postfix daemon directory 182 (pathname is controlled by the <b><a href="postconf.5.html#daemon_directory">daemon_directory</a></b> configuration 183 variable). 184 185 The command argument syntax for specific commands is specified 186 in the respective daemon manual page. 187 188 The following command-line options have the same effect for all 189 daemon programs: 190 191 <b>-D</b> Run the daemon under control by the command specified 192 with the <b><a href="postconf.5.html#debugger_command">debugger_command</a></b> variable in the <a href="postconf.5.html">main.cf</a> config- 193 uration file. See <a href="DEBUG_README.html">DEBUG_README</a> for hints and tips. 194 195 <b>-o {</b> <i>name</i> = <i>value</i> <b>}</b> (long form, Postfix >= 3.0) 196 197 <b>-o</b> <i>name</i>=<i>value</i> (short form) 198 Override the named <a href="postconf.5.html">main.cf</a> configuration parameter. The 199 parameter value can refer to other parameters as <i>$name</i> 200 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. 201 202 NOTE 1: With the "long form" shown above, whitespace 203 after "{", around "=", and before "}" is ignored, and 204 whitespace within the parameter value is preserved. 205 206 NOTE 2: with the "short form" shown above, do not specify 207 whitespace around the "=" or in parameter values. To 208 specify a parameter value that contains whitespace, use 209 the long form described above, or use commas instead of 210 spaces, or specify the value in <a href="postconf.5.html">main.cf</a>. Example: 211 212 /etc/postfix/<a href="master.5.html">master.cf</a>: 213 submission inet .... smtpd 214 -o smtpd_xxx_yyy=$submission_xxx_yyy 215 216 /etc/postfix/<a href="postconf.5.html">main.cf</a> 217 submission_xxx_yyy = text with whitespace... 218 219 NOTE 3: Over-zealous use of parameter overrides makes the 220 Postfix configuration hard to understand and maintain. 221 At a certain point, it might be easier to configure mul- 222 tiple instances of Postfix, instead of configuring multi- 223 ple personalities via <a href="master.5.html">master.cf</a>. 224 225 <b>-v</b> Increase the verbose logging level. Specify multiple <b>-v</b> 226 options to make a Postfix daemon process increasingly 227 verbose. 228 229 Other command-line arguments 230 Specify "{" and "}" around command arguments that contain 231 whitespace (Postfix 3.0 and later). Whitespace after "{" 232 and before "}" is ignored. 233 234<b>SEE ALSO</b> 235 <a href="master.8.html">master(8)</a>, process manager 236 <a href="postconf.5.html">postconf(5)</a>, configuration parameters 237 238<b>README FILES</b> 239 <a href="BASIC_CONFIGURATION_README.html">BASIC_CONFIGURATION_README</a>, basic configuration 240 <a href="DEBUG_README.html">DEBUG_README</a>, Postfix debugging 241 242<b>LICENSE</b> 243 The Secure Mailer license must be distributed with this software. 244 245<b>AUTHOR(S)</b> 246 Initial version by 247 Magnus Baeck 248 Lund Institute of Technology 249 Sweden 250 251 Wietse Venema 252 IBM T.J. Watson Research 253 P.O. Box 704 254 Yorktown Heights, NY 10598, USA 255 256 Wietse Venema 257 Google, Inc. 258 111 8th Avenue 259 New York, NY 10011, USA 260 261 MASTER(5) 262</pre> </body> </html> 263