I am seeking your help and advise. We are currently upgrading our virus gateway and within the product there is some added functionality to help us manage spam. Now, this new functionality involves using DNSBL's (Black lists), I have never been a real fan of black lists as they tend to be somewhat aggressive in their blocking techniques, leading to false positives.

My question, for those of you that are currently using one or more black lists, how would you rate the list your using? Do you get false positives, if so how many? Does using a black list appear to slow down your mail processing?

Your comments & advise is appreciated.