SpamAssassin is a free tool for mailservers to identify SPAM. It has a several parameters it checks (forged headers, HTML only content, blacklisted hosts, improper mail relays, etc) and assigns a score for every parameter. If the total score is greater than the threshold, it is marked as spam and either tagged, moved to a separate mailbox or deleted. I started using SpamAssassin in April of 2005 and it has caught thousands of messages. I know this isn’t large, but it made my inbox manageable.
Originally I set the threshold at 5 however this still lead to several messages a day. So I kept reducing the score, by 0.1 till I stopped at 4.5 and I only had 1 spam message every 3-4 days. I was completely satisified even though an occasional non-spam did get improperly marked (usually an SMS from a cell phone).
As of June 15, SpamAssassin has failed me. I am getting dozens of junk mail passing into my inbox daily. I am seeing scores of 3, 0 and even -0.7. Either the spammers got smart or the scores are not properly being assigned. I am using the latest version SpamAssassin 3.1.3 and I haven’t changed any options.
I may have to investigate further with my hosting provider. But I am curious if anyone else seen this?