Herb Martin wrote on Sat, 24 Sep 2005 07:17:06 -0500: > You RISK getting false positives with ANY RBL
Of course, yes. One better speaks of a "cost-value ratio" (with cost being "false positives" for your clients and value being the rejected spam and viruses). In this respect the combined Spamhaus list is probably the best. Only a few other RBLs can substantially add to that and still come close to the "cost". It should also be clear that most of the "false positives" aren't FP's by the RBLs definition but by the effect they have on your mail/users. > If you use Greylisting which offers virtually zero false > positives IN CONJUNCTION with quality RBLs like Spamhaus > rbl+xbl then you can eliminate false positives and still > benefit from blocking on such RBLs -- even less reliable > RBLs will work for this. Not sure how you combine that. AFAIR, greylisting is tempfailing the first SMTP delivery attempt, correct? Do you check the IP with RBLs and then tempfail it? So, you don't tempfail *every* connection attempt like "traditional" greylisting does? Kai -- Kai Schätzl, Berlin, Germany Get your web at Conactive Internet Services: http://www.conactive.com IE-Center: http://ie5.de & http://msie.winware.org
