Comment Selective greylist (Score 1) 301
The way I handle this is I greylist any email that comes in if:
1) it has no reverse dns
2) or the reverse dns matches certain patterns that indicate dynamic ip's
The rest comes in undelayed and is exposed to further checks. Note that it's ludicrous to require forward and reverse dns to resolve to the same thing. In today's age of hosting multiple domains in one server/cluster, it's just not reasonable to have PTR records defined that way.