SpamAssassin: SpamAssassin checks your incoming mail against a variety of rules and assigns a spam score. The higher the score, the more likely it is that this email is spam. This option is recommended, as it can help block the few spams that the SpamCop blacklist won't block. Start with a score of 5 and adjust up or down as needed. A lower score will catch more spam, but will catch a few more legit emails.
The selectable limits are: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15