High-performance spam filtering system
Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules including regular expressions, statistical analysis and custom services such as URL black lists. Each message is analysed by Rspamd and given a spam score.
According to this spam score and the user's settings Rspamd recommends an action for the MTA to apply to the message, for example, to pass, reject or add a header. Rspamd is designed to process hundreds of messages per second simultaneously and has a number of features available.
Rspamd is used by many email systems that are sensitive to the scanning rate and resources consumed for spam analysis.
The project is distributed under the terms of permissive Apache2 license and is written in C programming language using event-driven model. Plugins and advanced rules for rspamd are written in Lua programming language (optionally with LuaJIT compiler).