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- Header tests
- Body phrase tests. For more information, see SpamAssassinRules.
- Bayesian filtering (BayesFaq)
- Automatic address whitelist/blacklist (AutoWhitelist)
- Automatic sender reputation system (TxRep)
- Manual address whitelist/blacklist (ManualWhitelist)
- Collaborative spam identification databases (DCC, Pyzor, Razor2); See UsingNetworkTests.
- DNS Blocklists, also known as "RBLs" or "Realtime Blackhole Lists". See DnsBlocklists
- Character sets and locales
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