Table of Contents

Spam Filtering with ze-filter

Behaviour filtering

  1. Short term behaviour (rate limits)
  2. Medium term behaviour (rate limits)
  3. Greylisting
  4. Greylisting server

Content filtering

  1. Pattern Matching (REGEX)
  2. URLBL filtering
  3. Heuristic filter (Oracle)
  4. Bayesian Filtering - a statistical filter.
  5. Defining actions - what to do with that score…
  6. MUA filtering - how end users can explore headers added by ze-filter.

Miscelaneous Features

  1. Reputation - Realtime Black/White Lists
  2. 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.
  3. Bad Sender MX - Checking sender MX allows you to reject messages from people to who you can't answer.