First, I apologize if this has been asked over and over, or is common knowledge to everyone but me, but what is the point of meaningless spam? Who is sending it, and why? I'm talking about messages for something like "ultimate online pharmaceutical" (I get a lot of those) that come from spoofed addresses and have urls that go nowhere. No, I don't click the link, but I have done an nslookup, and every time I do it's a phony domain that can't get resolved.

The reason why I ask this is that this is the only spam I get (except for the occasional phish). My company has been looking at several different email servers, and currently we are evaluating exchange. There are a lot of spam filters out there that exchange supports, but it seems like the first line of defense for a lot of these is address blocking or ip blocking, which is useless when it's always a spoofed address, and always from a different ip. I know that Bayesian is supposed to be the way to go, but these spammers have come up with at least a hundred different ways to spell "vli agra," so it seems like that wouldn't help much either. Oh, and I didn't mention that not all of these are even advertisements for phony companies. Some of them just have excerpts from Lord of the Rings!

This leads to my second question - are there any drawbacks to using reverse dns? I have only seen one email system - Communigate - that has this feature, and it seems to be very effective. But why do other commercial email systems not support this, and why don't you see this as the first suggestion for blocking spam? Does it tie up system resources more than other filters would? It seems like it would be pretty nice to have spam dropped before it can even make it to the server.

I just a thought - and I mean this totally sarcastically - maybe it's the antispam companies that are responsible for all this junk spam?