Kai Schaetzl wrote: > Matt Kettler wrote on Mon, 12 Dec 2005 17:12:50 -0500: > > >>There's all different degrees of trust and more ways to go about it than we >>can >>count here :) > > > I think simpler. Either I trust it or not, so either I use it or not. :-) > > Kai >
Personally, I have yet to find a single RBL that's sufficiently accurate and FP free for me to begin to consider it for use as an MTA layer rejection criteria. But I consider using a RBL for MTA block an act of extreme trust. FWIW I'd require at least 5 nines of S/O to consider using an RBL as a block. Ideally I want it's FP rate to be on on the same order of magnitude as mail loss due to hardware failure on a reasonably redundant server (note: I'm talking probability of unrecoverable data loss, not percentage of uptime). The only RBL close to that accurate in the SA testing is XBL. No RBL is 99.999% accurate, Even XBL is only 99.994% (which rounds to a S/O of 1.000 in SA's STATISTICS-set1.txt, but if you re-extrapolate the raw numbers it is 272715 spam hits, 14 nonspam hits, or S/O 0.99994 which is still only 4 nines, not 5)
