Dan, Saturday, October 5, 2002 you wrote: DP> 70%? I believe the spam filter that comes free with Mac OS 10.2 DP> does that well by itself, though I haven't tested it for FPs yet.
The original poster, Keith Purtell, (subject "Newbie question about baseline") was wondering about the volume of trapped messages he was finding in his hold directory. He reported about 200 users, 250 messages normally in his spam directory on a daily basis, but 1000 on a particular Monday. We host only a little more than 200 users in 40 or so domains. In September our mail server handled 37,763 messages of which 17,153 (47%) were trapped as spam. But we inspect these messages prior to deleting and found 174 were not spam and which were passed on to the intended recipients. So for our 200 users on a daily basis we are deleting about 566 messages on average while passing a few more than that. Our known false positive rate is about 1%. The number of spam messages per user has definitely increased during the last few months. And it seems to be continuing to increase. However, I am not certain it is increasing more than e-mail usage in general which is definitely increasing. E-mail users are sending and receiving more e-mail. Some SPAM still makes it through to our users. We estimate for heavier volume users this ranges from 0 to 5 messages per day but about 1 message per day on average. We think this is pretty good. Most of our users also think it is pretty good although a few believe that even 1 spam message indicates total system failure. We have users that receive from hundreds of messages per day down to 1 or 2 messages per week. So how someone feels about spam that makes it through our system to them is a bit proportional to the volume of mail they handle as well as their own psychology. The spam that does make it through usually has failed no tests at all on the server. Desktop filters are so different and so individualized that I think it would be hard to conclude much about them in general. For instance with the Bat! that I use I can write various kinds of filters including programs. I can filter for words, regular expressions, and known/unknown senders based on my address book. If I used the latter (which I don't) I could easily mark more than 70% of my messages as spam. However, almost 100% of that would be false. And "false positives" are the problem with all filtering systems in my experience. It is quite easy to mark a large percentage of mail as spam. What's hard is reducing the false positive rate. I would not expect the MAC system to be different. In our system it was employing SNIFFER as part of our weighting system that provided us the greatest benefit in reducing false positives. Before SNIFFER we were in the 3% to 4% range and after SNIFFER we've been able to reduce that to 1%. So we believe the great benefit of SNIFFER for us has been in reducing false positives. This is especially important for us since we do inspect spam messages before deleting. SNIFFER's false positives remain in the subscribed lists but we've managed to improve that with Scott's negative weighting. On weekends our SPAM rate increases to 60% and sometimes greater and our false positive rate falls to .2% or lower. Total volume usually decreases though. Terry Fritts --- [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)] --- This E-mail came from the Declude.JunkMail mailing list. To unsubscribe, just send an E-mail to [EMAIL PROTECTED], and type "unsubscribe Declude.JunkMail". The archives can be found at http://www.mail-archive.com.
