Improving mail filter performance

Overview E-mail that flows into the server goes through several phases of filtering before final delivery, including: DNSBL lookups on handshake Deep protocol inspection DomainKeys/SPF validation SpamAssassin filtering Whitelist management Hash-sharing systems (DCC & Razor) Token-based regex matching Markup filtering Bayesian filtering All steps in the filtering process are automated, except for Bayesian filtering that works by…