AntiSpam: Up Close and Personal:
"A feature of Norton AntiSpam is its log of statistics. Here are my spam statistics since I began using the software on September 25, 2003, through Sunday November 9, 2003. Let's call that 44 days."

• E-mail scanned: 14,737 messages


• Average (over the 44 days): 335 per day


• Sent e-mail: 781 messages


• Valid e-mail: 6,023 messages(40.87%)


• Mail correctly identified: 5,996 messages (99.55%)


• >Spam: 8,714 messages (59.13%)


• Spam correctly identified: 8,103 messages (92.99%)

The most stunning number in this list is the sheer quantity of mail I receive. Something is clearly wrong with me—I must make a note to get myself an actual life (actually, a lot of it is security mailing lists that I don't read thoroughly). Maybe this weekend.

Still, it looks like I had 27 false positives (0.45% of valid mail), and that sounds like what I remember from my use of the product. NAS counts false positives when I manually scan the Spam folder in Outlook and mark non-spam messages with the "This is not Spam" button. Conversely, when I mark a message in the Inbox with the "This is Spam" button, it gets tracked as a false negative. The difference between the "Spam" and "Spam correctly identified" results totaled 611 messages or a hair over 7 percent of spam.

Now, I'm pretty happy with the ability of the product to find spam and reaching 93 percent is pretty good. At the same time, my instincts are that the 0.45 percent figure for false positives seems like a small number.

But those 27 false positives over 43 days may be non-trivial. This figure tells me I still should check the Spam folder periodically, and even relatively often, because if I don't I'll be intimidated by the amount of mail in it.

I was also struck by the fact that the statistics page reported that the last Antispam update was released on 8/29/2003. If they can go a month and a half without an update (and yes, I do run LiveUpdate frequently), Symantec can't be following the spam business the way they follow the virus business.…

One more bit of perspective on the amount of spam I receive. It's actually a lot more than that 59 percent figure presented by Norton. Some of my e-mail accounts are already filtered at the servers. Note the difference in the handling of three addresses of mine that are filtered through FrontBridge's server-based spam filtering. In the last month, that product found 523 spam messages and only one of them was a false positive.

Perhaps the answer is to switch to Outlook 2003. The numbers showed that it had not a single false positive, although it found far less spam. Oh well, the products get better, but the decisions we have to make continue to get harder.

http://www.eweek.com/article2/0,4149,1378794,00.asp?kc=EWNWS111103DTX1K0000599