Server Side Anti-Spam Technology

has anyone here had any experiance with mail server anti-spam software/filtering?

I am interested in the reverse verification technology. I have seen a few compans that try to sell individual licenses. I am looking more for a total server package. In other words, all domains on a single server. I dont know if this is possible or not

If anyone has any links/thought on this, I am open to suggestions.

I personally don't use server-side filtering because I'm afraid it might filter out some important e-mail sent to me. I use a client-side filter called POPFile that filters while it downloads your e-mail and seperates them into folders. If there is a mistake in filtering you 'correct' it and it 'learns'

My server uses spam-arrest, and it has been very good to me until now.

http://www.mirror.ac.uk/sites/spama....org/index.html

SpamAssassin seems to be pretty good as well. It (like many such programs, including PopFile) just adds spam headers to emails, giving them a spam rating. You can then set up filters on the client-side to interpret the headers and file mail as needed. You can also set it up to reject too-large attachments, etc. I'm not sure about deployment across domains, but since it plugs into the mail server itself and mail servers typically can listen for mail on multiple domains, I don't imagine it'd be a problem.

yeah I went ahead with spam assassin. it is running good at the moment.

I was really hoping to get into the reverse address verification stuff, but jeez it is expensive.

I believe SpamAssassin'll do that, won't it? Doesn't it do a reverse DNS lookup and kill mail it can't do a reverse lookup on?