an effective anti-spam with milter - milter manager


milter-test-client — milter side milter protocol implemented program


milter-test-client - milter side milter protocol implemented program


milter-test-client [ option ... ]


milter-test-client is a milter that just shows received data from MTA. It also shows macros received from MTA, it can be used for confirming MTA's milter configuration.

Postfix's source archive includes similar tool. It's src/milter/test-milter.c. It seems that it's used for testing Postfix's milter implementation. But test-milter doesn't show macros. If you have a milter that doesn't work as you expect and uses macro, milter-test-client is useful tool for looking into the problems.



Shows available options and exits.


Specifies a socket that accepts connections from MTA. SPEC should be formatted as one of the followings:

  • unix:PATH

  • inet:PORT

  • inet:PORT@HOST

  • inet:PORT@[ADDRESS]

  • inet6:POST

  • inet6:PORT@HOST

  • inet6:PORT@[ADDRESS]


  • unix:/tmp/milter-test-client.sock

  • inet:10025

  • inet:10025@localhost

  • inet:10025@[]

  • inet6:10025

  • inet6:10025@localhost

  • inet6:10025@[::1]


Specifies log output items. You can specify multiple items by separating items with "|" like "error|warning|message".

See Log list - Level for available levels.


Specifies log output path. If you don't specify this option, log output is the standard output. You can use "-" to output to the standard output.


Logs verbosely.

"--log-level=all" option has the same effect.


Logs Syslog too.


Doesn't show any information received from MTA.


Reports memory usage each milter session finished.

When MILTER_MEMORY_PROFILE environment variable is set to 'yes', details are reported.


% MILTER_MEMORY_PROFILE=yes milter-test-client -s inet:10025


Runs as daemon process.


Runs as USER's process. root privilege is needed.


Runs as GROUP's process. root privilege is needed.


Changes UNIX domain socket group to GROUP when "unix:PATH" format SPEC is used.


Runs N_WORKERS processes to process mails. Available value is between 0 and 1000. If it is 0, no worker processes will be used.

NOTE: This item is an experimental feature.


Uses BACKEND as event loop backend. Available values are glib or libev . If you use glib backend, please refer to the following note.

NOTE: For the sake of improving milter-manager performance per process, event-driven model based architecture pattern is choosed in this software. If this feature is implemented by glib, it is expressed as a callback. Note that glib's callback registration upper limit makes the limitation of the number of communications. This limitations exist against glib backend only.


Uses SIZE as send packets buffer size on end-of-message. Buffered packets are sent when buffer size is rather than SIZE bytes. Buffering is disabled when SIZE is 0.

The default is 0KB. It means packet buffering is disabled by default.


Shows version and exits.


The exit status is 0 if milter starts to listen and non 0 otherwise. milter-test-client can't start to listen when connection spec is invalid format or other connection specific problems. e.g. the port number is already used, permission isn't granted for create UNIX domain socket and so on.


The following example runs a milter which listens at 10025 port and waits a connection from MTA.

% milter-test-client -s inet:10025