BackupsSpam Assassin. Serious Spam Filtering
Spam Assassin
SpamAssassin is a mature, widely-deployed open source project that serves as a mail filter to identify Spam. SpamAssassin uses a variety of mechanisms including header and text analysis, Bayesian filtering, DNS blocklists, and collaborative filtering databases. SpamAssassin runs on a server, and filters spam before it reaches your mailbox.
Advantages
SpamAssassin's practical multi-technique approach, modularity, and extensibility continue to give it an advantage over other anti-spam systems. Due to these advantages, SpamAssassin is widely used in all aspects of email management. You can readily find SpamAssassin in use in both email clients and servers, on many different operating systems, filtering incoming as well as outgoing email, and implementing a very broad range of policy actions. These installations include service providers, businesses, not-for-profit and educational organizations, and end-user systems. SpamAssassin also forms the basis for numerous commercial anti-spam products available on the market today.
How It Works
This flexible and powerful set of Perl programs, unlike older spam filtering approaches, uses the combined score from multiple types of checks to determine if a given message is spam.
Its primary features are:
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Header tests
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Body phrase tests. For more information, see
SpamAssassinRules
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Bayesian filtering (BayesFaq)
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Automatic address whitelist/blacklist (AutoWhitelist)
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Manual address whitelist/blacklist (ManualWhitelist)
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Collaborative spam identification databases (DCC, Pyzor, Razor2); See
NetworkTests.
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DNS Blocklists, also known as "RBLs" or "Realtime Blackhole Lists". See
DnsBlocklists
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Character sets and locales
Even though any one of these tests might, by themselves, mis-identify a Ham or Spam, their combined score is terribly difficult to fool.
