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.
What ports does Razor use?: NetTestFirewallIssues
I get errors about unblessed references from Razor: RazorUnblessedRefs
How do I report a spam to Razor?: ReportingToRazor
How do I report a whole mailbox full of spam to Razor? SpamAssassin only handles single mail messages: ReportingMboxesToRazor
I get 'bad file descriptor' errors with amavisd-new and Razor2: RazorBadFileDesc
How can I tell if SpamAssassin is using Razor?: RazorHowToTell
I upgraded to 2.6x and get "razor2 check skipped": RazorInsecureDependency
Razor2 check fails with Can't locate object method "new": RazorCantLocateNew