Re: question on ptr rr

There are quite a few sites (including the freebsd.org mailserver, and, on a case by case basis, even AOL) that do refuse mail from IPs without rDNS, but turning on a "must have rDNS or you can't email us" setting will definitely result in a non trivial amount of false positives.

but, i suspect that more and more of the world will go that way, maybe slowly. so how does one judge when a site which hosts public lists can do so without causing serious discomfort for folk? is there some objective measure, or do we all just shoot in the dark? randy