UPDATE: See the latest DNSBL Safety Report for current recommendations.
SpamTips.org occasionally looks at the results of Spamassassin’s nightly masscheck at RuleQA in order to analyze the performance and safety of add-on DNSBL’s. It is vitally important to know how a DNSBL is performing before deciding if it is a good idea to use it. Many of the below DNSBL’s were tested because they indicated strong performance in other comparisons. Our analysis demonstrates that raw detection numbers can be misleading, as ham safety ratings and overlaps with other rules must be taken into consideration.
Today’s report examines Hostkarma, SpamEatingMonkey, Tiopan, UCEProtect, Mailspike, and Nix Spam and Lashback UBL. Recommended scores below are what I personally use in production.