This is an old revision of the document!

clapf is an open source email content filter application. It includes a statistical (inverse chi-square) antispam module, and an interface to several anti-virus products, a web ui (including a spam quarantine) written in PHP.

It supports virtual users, URL blacklists, whitelists, LDAP directories, policy groups, minefield and many more.

clapf can be used as an after queue content filter with Postfix (including as an appliance) and Exim.

clapf also can work as an appliance before Exchange or virtually any SMTP server.

To subscribe send a mail to, or view the archive. Please take a look at the mailing list guidelines.