Why is the spam filter not quarantining as much spam?

The new spam filter may not seem to be quarantining as much spam because it has more aggressive checks, and handles spam in a different way, than our previous filter, Postini.

During the filtering process, Postini would quarantine any messages that it thought was spam, even blatant spam messages. Because of this, most users are used to sifting through several hundred spam messages daily. Our new spam filter, Barracuda, handles spam differently, in both what checks it uses to determine a message is spam and how it handles messages that are blatant spam or messages that are real and just have spam qualities.

Because spam is handled more aggressively, you will see fewer messages in your quarantine, but only because there is no need to sift through the heavy volume of blatant spam messages.