Apache SpamAssassin 3.1.0 has been released. It represents a major update, the Apache Foundation says, and acts as a mail filter that uses advanced statistical and heuristic tests to identify spam.

Some features of SpamAssassin, according to Apache:

* Wide-spectrum. SpamAssassin uses a wide variety of local and network tests to identify spam signatures. This makes it harder for spammers to identify one aspect which they can craft their messages to work around.

* Free software. It is distributed under the same terms and conditions as other popular open-source software packages such as the Apache web server.

* Easy to extend. Anti-spam tests and configuration are stored in plain text, making it easy to configure and add new rules.

* Flexible. SpamAssassin encapsulates its logic in a well-designed, abstract API so it can be integrated anywhere in the email stream. The Mail:SpamAssassin classes can be used on a wide variety of email systems including procmail, sendmail, Postfix, qmail and many others.

* Easy Configuration. SpamAssassin requires very little configuration; you do not need to continually update it with details of your mail accounts, mailing list memberships, etc. Once classified, site and user-specific policies can then be applied against spam. Policies can be applied on both mail servers and later using the user's own mail user-agent application.