I still love using DNSBL as part of a score-based approach. Add Bayesian filtering, spf/dkim scoring, a greylist, and postfix options like RDNS checks. I see a

I still love using DNSBL as part of a score-based approach. Add Bayesian filtering, spf/dkim scoring, a greylist, and postfix options like RDNS checks. I see a few spam a week, have never seen a false positive. I think greylisting made the biggest difference after sane-sender checks.