Ten Minutes to a
Cleaner Mailbox"> The actual installation process took about 10 minutes. The most difficult part was remembering where the SMTP protocol settings live so I could turn the filtering on. Basically, IMF works by looking at incoming messages and, using techniques Microsoft isnt willing to fully disclose, assigned a numeric rating to each. These ratings reflect a confidence level in whether a particular message is spam and correspond to filter settings in IMF. The server filters themselves work in two ways: The first is the gateway filter, which can delete or reject messages before they are ever sent to users mailboxes. The second determines whether a message is sent to the users inbox or "junk mail" folder.It is probably best to set the gateway filter to a relatively low level and then have it reject or trash those messages most likely to be spam. The remaining messages would be filtered at a level that balances false positives with the amount of spam that clears the filter and ends up in users inboxes. Right now, I have my gateway filter set to do nothing, while the mailbox filter was made tighter after the default setting allowed too much spam into my inbox. Lowering the threshold to 6 seems to have solved that problem. Before going further, I should mention that my e-mail address has appeared in print and on Web sites on many occasions and if there is a spam list Im not onsometimes several timesId be pretty surprised. Some days I receive more than 2,000 spam messages. So far, out of more than 400 messages processed, four spam messages have been delivered to my mailbox, a pretty impressive catch rate. On the other side, I have had a somewhat larger number of false positives, but only from two senders and all mailing list messages that could easily be mistaken for spam. Adding the senders to my "safe sender" list or my contact list ought to solve this problem. This tallies up to an amazing 1 percent failure rate and just enough false positives to keep me from setting the filtering level any tighter until Ive had a chance to watch things for a while longer. My guess is the astoundingly low failure rate is a bit unusual. The Outlook 2003 filters were letting about 5 percent of the spam through, with only occasional false positives. Even at that level, I was very pleased with the filters ability to solve my spam problems. Again, your mileage will vary and so will everyones as the battle between Microsoft and spammers ebbs and flows, the bad guys finding new ways to get around the filters and the good guys creating new filters. Meanwhile, watch my coursey.eweek.com Blog and I will report on my experiences with IMF over the next few weeks.
The default number setting for both the gateway and mailbox filter is eight. Oddly, a lower number equates to more filtering while a higher number equals less. Lowering the number catches more spam, but also increases the likelihood of false positives.