hi ,
I have set up a Mailserver with Postfix+MailScanner+SpamAssassin+Cyrus. Everything went fine for the first 4 months till recently when Bayes started showing some unusual behaviour.
For a same kind of mail Bayes is giving a variable score. Say i recieved a mail for which Bayes_90 gave a score of 2.101, 3 hours later when the same kind of mail appeared again it was Bayes_60 score with 1.592 and then in the next one hour for the same mail it got a negative value. This has really started making me sweat, Many of the spam messages get detected in one instance and are left undetected in other. I suspected my sa-learn mechanism to be behind this variable score as for the given mails Bayes might have got some more number of HAM tokens during feedback. But the kind of feedback mechansim i have implemented in not reading from any inbox folder but works like this any mails to [EMAIL PROTECTED] is fed to the sa-learn using a perl wrapper script. When i checked my logs for a possible HAM feedback during the time period, I didnt find a single entry for HAM feedback which left me in more dilemma.
My next suspect is the Bayes DB expiry. I have read in many documentation that we need expire and rebuild the Bayes DB for old tokens to save disk space from being eaten up. But since i had a lot of hard drive space i decided not to expire the database and now my database size is 39 M. I feel tht perhaps the database has grown too large in size to be effectively parsed. But still I am in confused state. Is this the reason of the abnormal behaviour of Bayes ? Is there any other reason other than disk space why we need to expire and rebuild the database ? Guys please help me out. Atleast let me know what probably could be the reason of this abnormal scoring of Bayes.
regards Rakesh
