Spam Filtering with ze-filter

Short term behaviour (rate limits)

Medium term behaviour (rate limits)

Greylisting

Greylisting server

Pattern Matching (REGEX)

URLBL filtering

Heuristic filter (Oracle)

Bayesian Filtering - a statistical filter.

Defining actions - what to do with that score…

MUA filtering - how end users can explore headers added by ze-filter.

Reputation - Realtime Black/White Lists

Recipient Access - Recipient access is useful both for detecting dictionary attacks and to, e.g., limit access to some addresses only to some known networks.

Bad Sender MX - Checking sender MX allows you to reject messages from people to who you can't answer.