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Collaborative spam identification databases (HashSharingSystem)
SpamAssassin includes support for three different Hash-based Network Tests, which compare fingerprints for received messages against shared lists of previously-seen spam messages.
- The Razor database http://razor.sourceforge.net by Vipul Ved Prakash and Jordan Ritter allow Unix clients to work out of the same database used by the commercial customers of the Cloudmark system. See UsingRazor for help on using Razor.
- Pyzor, a completely free database and software system, written by Frank Tobin. http://pyzor.sourceforge.net
- DCC, the Distributed Checksum Clearinghouse http://www.rhyolite.com/anti-spam/dcc/ . See UsingDcc for help with DCC issues.
Razor and Pyzor, in the past, have intermittently had outages that can result in timeouts and a higher system load. Set the razor_timeout and pyzor_timeout values to a low value, if you're worried about this.
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