On 11/29/2012 18:54, David F. Skoll wrote:
[My gut instinct says that a reasonable greylisting interval is too short for most DNSBLs to react. Pyzor/Razor/DCC may be somewhat more adept at reacting quickly.]
Something trap-driven like NIX is a candidate. No, it's not safe enough to reject based on it's output, but it was worth use in a scoring system. Invalument too responds reasonably quickly, enough that it sometimes tripped during the greylist period.
The other trick is how you define reasonable. A reasonable greylist period for greylisting all mail is about 3 seconds, otherwise you'll have users screaming. However, if you only greylist questionable stuff to start with (rDNS failures, mismatches, etc, SPF fails, borderline-spammy stuff, DUL hits), you can get away with much longer times since most of it is crap anyway but a greylist period can help let the odd gem through.
-- Dave Warren http://www.hireahit.com/ http://ca.linkedin.com/in/davejwarren
