mtpolicyd - the mtpolicyd executable
version 1.11
mtpolicyd is a policy daemon for postfix access delegation.
It can be configured to accept connections on several ports from a postfix mta. For each port a VirtualHost can be configured and for each VirtualHost serveral Plugins can be configured.
mtpolicyd - a modular policy daemon for postfix
In postfix main.cf:
smtpd_recipient_restrictions = check_policy_service inet:127.0.0.1:12345
In mtpolicyd.conf:
# listen on port 12345 (multiple ports can be seperated by ',') port="127.0.0.1:12345" # defined host for this port <VirtualHost 12345> name=example_vhost <Plugin spamhaus_bl> module="RBL" domain="sbl.spamhaus.org" mode=reject </Plugin>
This check will execute a simple RBL lookup against dbl.spamhaus.org. </VirtualHost>
mtpolicyd [-h|--help] [-c|--config=<file>] [-f|--foreground] [-l|--loglevel=<level>] [-d|--dump_vhosts]
Show available command line options.
Specifiy the path to the configuration file.
Do not fork to background and log to stdout.
Overwrite the log level specified in the configuration with the specified level.
Parse VirtualHosts configuration, print it to stdout and exit.
The configuration file is implementend with Config::General which allows apache style configuration files.
mtpolicyd accepts global configuration parameters in the style:
key=value
Comments begin with '#'.
VirtualHosts must be configured with VirtualHost sections:
<VirtualHost <portnumber>> name=<name of the vhost> </VirtualHost>
Each VirtualHost should contain at least on Plugin.
<VirtualHost <portnumber>> name=<name of the vhost> <Plugin <name of check> > module = "<name of plugin>" # plugin options key=value </Plugin> </VirtualHost>
For individual plugin configuration options see the man page of the plugin:
Mail::MtPolicyd::Plugin::<name of plugin>
user id to run as
group id to run as
location of the pid file
Verbosity of logging: 0=>'err', 1=>'warning', 2=>'notice', 3=>'info', 4=>'debug'
ip address to bind to.
comma separated list of ports to listen on.
The minimum number of client processes to start.
The minimum number of client processes that should hanging around idle and wait for new connections.
If the number of free processes is below this threshold mtpolicyd will start to create new child processes.
The maximum number of idle processes.
If the number of idle processes is over this threshold mtpolicyd will start to shutdown child processes.
The absolut maximum number of child processes to start.
Number of requests after that mtpolicyd closes the connection or no limit if set to zero.
Should be the same value as smtpd_policy_service_reuse_count_limit (postfix >2.12) in postfix/smtpd configuration.
Maximum total time for one request.
Connection string for the database in perl-DBI format. See DBI.
db_dsn="dbi:mysql:mail"
Name of database user.
Password of database user.
A comma seperated list of memcached servers used for session tracking.
memcached_servers="127.0.0.1:11211"
Use a namespace for storing sessions in memcached
Expire time for memcached entries.
Time to wait before retry to acquire lock on a session object.
Will be increased with every try. (50,100,150,...)
Number of maximum retries for acquiring a session lock.
After this timeout the lock will destroy itself.
mtpolicyd uses a session managemend based on memcached.
mtpolicy will generate a session for each mail passed to it and store it within memcached. The attached session information will be available to all following plugins across child processes, virtual hosts and ports.
Plugins will use this session information to cache lookup etc. across multiple requests for the same mail. Postfix will send a query for each recipient and for each configured check_policy_service call.
The policy daemon will process all plugins in the order they appear in the configuration file. It will stop as soon as a plugin returns an action and will return this action to the MTA.
Most plugins can be configured to not return an action if the performed check matched.
For example the RBL module could be set to passive mode and instead a score could be applied to the request:
<Plugin spamhaus> module = "RBL" mode = "passive" domain="zen.spamhaus.org" score=5 </Plugin>
Check the documentation of the plugin for certain score/mode parameters. Plugin may provide more than one mode/score parameters if the do several checks.
Now if you configure more than one RBL check the score will add up. Later an action can be taken based on the score. The ScoreAction plugin will return an action based on the score and the AddScoreHeader plugin will prepend the score as a header to the mail:
<Plugin ScoreReject> module = "ScoreAction" threshold = 15 action = "reject sender ip %IP% is blocked (score=%SCORE%%SCORE_DETAIL%)" </Plugin> <Plugin ScoreTag> module = "AddScoreHeader" spam_score=5 </Plugin>
If you configure a database this database connection will be available to plugins. For example the SqlList plugin can be used to implement a black or white list based on an SQL query. Or the SqlUserConfig plugin could be used to query a database for additional configuration options.
db_dsn=DBI:mysql:mtpolicyd db_user=user db_password=password
Markus Benning <ich@markusbenning.de>
This software is Copyright (c) 2014 by Markus Benning <ich@markusbenning.de>.
This is free software, licensed under:
The GNU General Public License, Version 2, June 1991
To install Mail::MtPolicyd, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Mail::MtPolicyd
CPAN shell
perl -MCPAN -e shell install Mail::MtPolicyd
For more information on module installation, please visit the detailed CPAN module installation guide.