Manual browser: master(5)
|MASTER(5)||File Formats Manual||MASTER(5)|
NAMEmaster - 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.
After changing master.cf you must execute "postfix reload" to reload the configuration.
The general format of the master.cf 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 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.
- Service name
- The service name syntax depends on the service type as described next.
- Service type
- Specify one of the following service types:
The service listens on a TCP/IP socket and is accessible via the network.
The service listens on a UNIX-domain socket and is accessible for local clients only.
The service listens on a FIFO (named pipe) and is accessible for local clients only.
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.
- 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 main.cf file).
- Chroot (default: y)
Whether or not the service runs chrooted to the mail queue directory (pathname is controlled by the queue_directory configuration variable in the main.cf file).
- 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.
- Process limit (default: $default_process_limit)
The maximum number of processes that may execute this service simultaneously. Specify 0 for no process count limit.
- 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.
- Run the daemon under control by the command specified with the debugger_command variable in the main.cf configuration 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.
submission inet .... smtpd
submission_mumble = text with whitespace...
- Increase the verbose logging level. Specify multiple -v options to make a Postfix daemon process increasingly verbose.
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
Lund Institute of Technology
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA