Just a couple of corrections to two of the posts in this thread:
I simply have some problems with /this/ current incarnation of a best practice, and I was querying whether it had applicability outside of the SORBS/Trend Micro world.
I think you are mixing/confusing SORBS and MAPS. MAPS was bought by Trend and is run as a service based on subscription fees. SORBS is whatever it is. If you don't like SORBS, that's great, but don't tar Trend with that brush.
2) Your reply to Dave's post is not useful. It's not even useful if you consider it pure hyperbole for effect. There are many ways to reduce spam, the "single most effective" does not stop even 50%.
Actually, that's not true. I don't want to get into an argument about "single most effective," but I can guarantee that using a good reputation service will block more than 50% of the incoming spam to your network. The leading ones normally hit the 80% range. In fact, many of the popular anti-spam appliances are completely miserable at the content filter end which is applied post-reputation service; without reputation filtering, they wouldn't be worth using. (My information is based on monthly testing of anti-spam appliances we have conducted for the past 5 years. For example, this month we are looking at 43 different appliances and 25 reputation sevices) jms -- Joel M Snyder, 1404 East Lind Road, Tucson, AZ, 85719 Senior Partner, Opus One Phone: +1 520 324 0494 jms@Opus1.COM http://www.opus1.com/jms