do you use anti-spam services?

[SoopaStar]

http://www.declude.com/junkmail/support/ip4r.htm

My company uses Syamntec Antivirus for SMTP Gateways and it provides some basic anti-spam services. We can specify up to 3 DNSRBL lists to help block spam. The link above lists a bunch of these, and I was wodnering if anyone uses any of them or if anyone has an opinion on them?
I have four of these servers setup and we used to use the relays.osirusoft DNSRBL, but they unfortuately stopped their serivces.
any reccomendations? We are running the Solaris version of the software. Our mail servers are running an older netscape enterprise mail software that is hard to find another antispam software for.

Paul

[AzKidd69]

not sure if they support your softwarwe but check out http://www.cloudmark.com they have an enterprise level solution that instead of DNSRBL's it uses checksums of emails and the users block spam.. I personally have NEVER had a legitimate email blocked by it BUT I do have a few spams a day that slip thru BUT nothing like what it catches I am using the home based version of it tho (outlook plug-in basically)...