Introduction to SpamAssassin

What is spam?

“Spam” is unsolicited commercial email, formally known as UCE, but better-known as spam.

SpamAssassin is a spam-detection program that uses several advanced techniques to detect and filter potential email spam. SpamAssassin can be integrated into the mail server to automatically filter all spam for a domain and uses rules, or “tests,” to determine what is spam and what is not.

As each email is tested, it is scored according the rules. Email is considered to be spam if it scores above a configurable set point. Each user can configure SpamAssassin’s threshold for determining if an email is spam, suspicious, or not spam.

Rules are not the only method of spam detection, however: SpamAssassin also supports network-based filtering such as DNS-based blacklists, URI-based blacklists, hash algorithms, and checksum-based filters. SpamAssassin can also “learn” what is spam and what is not spam by using a Bayesian filter, but this requires the user to mark messages as spam or not-spam.

SpamAssassin in cPanel

cPanel installations typically come with SpamAssassin. In cPanel, SpamAssassin is in the Mail section:

SpamAssassin is enabled by default, with a pre-configured score setting of “5,” which is configurable by the domain owner. Higher settings will let more email through; lower settings will mark more email as spam. Individual users should keep the default setting while Internet Service Providers (ISPs) should consider a more conservative setting of 8 or 10.

Additional configuration

Additional configuration settings are available: simply click the Configure SpamAssassin button:

In the “Configure SpamAssassin” screen, you can enter blacklist entries (mail from undesired addresses that may not be marked as spam), whitelist entries (mail from desired addresses that may be marked as spam), and individual score entries (assigns scores to any given test).