Spam Filtering Software Tools

Spam filtering tools and technologies are available in many forms. Some commercial server side spam filters, Spam Assassin will compare each incoming email against a set of rules. Each rule contributes a little more to the overall decision as to whether or not an email is spam.

RBL Filtering - RBL or Realtime Black List is typical done on the server. When an email comes into your server, the sending IP address is checked against a list of known spammers IP addresses. Read more about RBL Filtering

SpamAssassin Filter - An open source spam filter is a big piece of the over all puzzle of spam filtering. As a major component in your spam blocking strategy, it's important to understand how a SpamAssassin filter works.

Bayesian Filtering - This filtering method looks at an incoming email and develops an inferential statistics to develop probability score. Probability that an incoming email is spam or not spam. This is a very popular technology for client side spam filtering due to its adaptability. A Bayesian filter can 'learn' from its mistakes in theoretically improve.

There are some very important rules to follow regarding the learning process for a good bayesian database. And as part of a comprehensive anti spam strategy. You can learn more about Bayesian filtering

Spam blacklist and whitelist - Maintaining an address blacklist can be a real waste of time except for proper circumstances. Address blacklisting is a simple means of blocking unwanted emails from sources that will not honor their unsubscribe procedures. While whitelisting is used to prevent false positives. Read all about the proper and inappropriate uses for an address blacklist / whitelist.