SpamAssassin is a mail filter which attempts to identify spam using a variety of mechanisms including text analysis, Bayesian filtering, DNS blocklists, and collaborative filtering databases. It is designed to be called from a user’s .procmail or .forward file, but can also be integrated into a Mail Transport Agent (MTA).
SpamAssassin uses a wide range of heuristic tests on mail headers and body text to identify “spam”, also known as unsolicited commercial email.
Once identified, the mail can then be optionally tagged as spam for later filtering using the user’s own mail user-agent application.
SpamAssassin typically differentiates successfully between spam and non-spam in between 95% and 100% of cases, depending on what kind of mail is received and training of its Bayesian filter. Specifically, SpamAssassin has been shown to produce around 1.5% false negatives (spam that was missed) and around 0.06% false positives (ham incorrectly marked as spam).
SpamAssassin also includes plugins to support reporting spam messages automatically or manually to collaborative filtering databases such as Pyzor, DCC, and Vipul’s Razor.
SpamAssassin is a project of the Apache Software Foundation (ASF).
Features include:
- Wide-spectrum: SpamAssassin uses a wide variety of local and network tests to identify spam signatures.
- 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.
Website: spamassassin.apache.org
Support: FAQ
Developer: Apache Software Foundation
License: Apache License 2.0
SpamAssassin is written in C and Perl. Learn C with our recommended free books and free tutorials. Learn Perl with our recommended free books and free tutorials.
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