> Which means each server has an individual greylisting database, and mail
> could potentially (worst case) be bounced three times before getting
> through. Has anyone solved this problem already?
..
http://sqlgrey.sourceforge.net/
We have postfix+sqlgrey deployed across several mail hosts. It would be nice to have a replicated postgres behind it but otherwise it does the job very nicely. Also seen here: Similar dramatic reduction in inbound crap and recent increase in abuse of relays behind legit whitelisted hosts.
Cheers,
Mark.