Those of you who run your own email servers -- do any of you run it from a residential connection with dynamic ip address? Or do you pay extra for a static ip address/host using a VPS?
Depending on your upstream provider, though, it ranges from difficult to impossible to get the reverse DNS for "your" static IP addresses set to something reasonable. Maybe for a business account they would do it...but for a home connection, forget it. Trouble tickets asking for reverse DNS updates will be ignored.