Mostly good but increasingly frustrating.
- It was a mixture of SpamAssassin, Greylisting, Blackhole DNS, and adhering to SPF instructions from other domains.
- Unfortunately I've had to abandon Greylisting due to the growing number of organisations that don't understand temporary delivery failures (usually Enterprise software that's delivering email directly to targets on the Internet) *and* who use a different (machine generated) sender or machine address for each delivery attempt.
- SPF is a joke. Too many organisations either have "we don't care what we do" SPF declarations or else declare