References

• Home site: https://rspamd.com

Description

Rspamd is a complex spam filter that allows to estimate messages by a number of rules including regular expression, statistical analysis and custom services, such as URL black lists. Each message is analysed by rspamd and got a spam score.

According to this spam score and user’s settings rspamd recommends to apply an action for this message to MTA, for example to pass, to reject or to add spam header. Rspamd has own unique features among spam filters:

• event driven architecture allowing to process many messages at a time;
• flexible syntax of rules allowing to write rules in lua language;
• a lot of plugins and rules shipped with rspamd distribution;
• highly optimized mail processing;
• advanced statistic;

All these features allow rspamd to process messages fast and demonstrate a suitable spam filtering.

Installation

Rspamd runs on a Unix like operational systems. FreeBSD users can use ports collection (mail/rspamd) for rspamd installation. Ubuntu users can use launchpad PPA:

https://launchpad.net/~vsevolod-n/+archive/rspamd

Users of other OSes should use sources to build and install rspamd. Alternatively you could check the OpenSUSE build system for packages suitable for your environment:

http://software.opensuse.org/download.html?project=home%3Acebka&package=rspamd

There are packages for debian and CentOS/RHEL distribution. Debian users could use debuild utility to create the binary packages of rspamd. CentOS/RHEL users could use spec file and other RedHat specific stuff from centos folder. The users of other systems could try to adopt some package or just to build from sources.

Build requirements

Rspamd requires several 3-rd party software to build and run:

• libevent - asynchronous event library
• glib - common purposes library
• gmime - mime parser
• lua - extendable scripting language
• cmake - advanced software build system

You can either install them from sources or (recommended) install using package manager of your system.

Build process

To build rspamd from the sources please follow these steps:

1. Clone rspamd repository:

$ git clone --recurse-submodules https://github.com/vstakhov/rspamd.git

1. Install all dependencies and create a build directory:

$ mkdir rspamd.build

1. From rspamd build directory run cmake with specifying the path to the source directory, for example:

$ cmake ../rspamd

1. After configure process has finished you can build rspamd using make:

$ make
# make install

After installation binaries, rules, plugins and a sample configuration will be installed in the target directories (prefixed by /usr/local by default).

Further Actions

You can improve the quality of rspamd filtering by learning its statistical module. The easiest way to do it is to use rspamc client (you can setup a custom email alias to pipe messages to rspamc)

$ rspamc -P 'q1' learn_spam [ file1 [file2 [...]]]
$ rspamc -P 'q1' learn_ham [ file1 [file2 [...]]]

Note: you should consider to change default controller’s password q1 to a more secure one specified in the controller section of configuration.

Also a system administrator might want to customize rule’s weights or actions thresholds. This can be done easily by editing metrics.conf configuration file.

For writing new rules you can examine the main rspamd documentation and lua api guide and reference.