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. Some flavours are available, depending on the machine architecture: no_luajit Disable luajit, available on all architectures (unflavoured) Enable luajit, available on amd64/i386 hyperscan Use Intel's hyperscan library, available on amd64, requires certain CPU features.