Personal Antispam is the ultimate spam-fighting tool for Mac OS X. Personal Antispam analyzes your incoming e-mail, determining which messages are spam and which are valid messages, and does so in several ways: by checking a whitelist and blacklist of addresses, examining message headers, content or layout, analyzing URLs in messages, and much more.
Unlike the spam filters provided with e-mail programs such as Apple Mail, Microsoft Entourage or Microsoft Outlook, Personal Antispam is intelligent. When you first install Personal Antispam, its performance is similar to that of the filters included with e-mail programs. But as you use it more and more, having the program learn from your spam and from your legitimate e-mail, Personal Antispam outperforms any spam filter available for Mac.
Personal Antispam uses a set of plug-ins to provide the most powerful spam filter available. Personal Antispam uses the following techniques to filter spam:
Lexical filtering (also known as Bayesian analysis),
Whitelist and blacklist filters,
URL filters, using a database of known spam URLs,
Personal Antispam also looks for specific types of headers and layout used in HTML messages, which are most often used for spam, allowing the program to not only search for content, but also for the subtle ways that spammers craft their messages.
Spam techniques are constantly changing, and Personal Antispam offers regular updates to its filters to fight new types of spam as they appear, and to update its database of spam URLs.