You can change how Spam Assassin deals with spam. The following options are available:
required_hits - The number of e-mails received before a certain e-mail is considered spam.
rewrite_subject - Alter the subject line of spam e-mail. Enter 1 to enable or 0 to disable.
subject_tag - Text added to the subject line of spam e-mails. rewrite_subject must be enabled for this to work.
blacklist_from - Enter an e-mail address that you always want classified as spam. The asterix symbol (*) can be used as a wildcard.
whitelist_from - Enter an e-mail address that you never want classified as spam. The asterix symbol (*) can be used as a wildcard.
Click on the Spam Assassin link in the Mail area.
Click on the Configure Spam Assassin button.
Change the settings as required.
Click on the Save button.