SpamAssassin allows the user and system administrator to improve detection of spam using a number of techniques. Whitelists aid in preventing false-positives. SpamAssassin's auto-whitelist will prevent an occasional spam-like email from an otherwise spam-free correspondent from being filtered as spam.
The spam threshold of whitelists can be altered to reduce false-positive or false-negative emails, and individual rule scores can be altered to prevent incorrect classifications. Character sets and languages can be used to filter out spam from other countries or regions.