Dmitri V. Ivanov put forth on 10/22/2010 11:01 AM:
On Fri, Oct 22, 2010 at 05:58:46AM -0500, Stan Hoeppner wrote:
It was donated to me, and by default the community, by an anonymous poster to the spam-l mailing list, quite some time ago. We were having a discussion about blocking dynamic/generic rDNS hosts. Many of us were using really coarse regexes that others felt would catch alot of ham sources instead of just broadband/dynamic bots.
Some of my friends prefer way to put dynamic hosts (and hosts which don't provide real domainname/IP literal with HELO/EHLO) into graylisting. This way gives some failover to mistakes within list of dynamic hosts and there is no conflict with large mail systems which sends outbond mail from different hosts (they moustly have reverse DNS records not matching lists).
Sorry for offtopic.
I think most of us that use something like this pcre also use greylisting. I use super selective Postgrey, well after all other checks, as a safety net of sorts.
-- Stan