I know people have been bugging me for a while to try and cleanup spam on NERP. I'm still re-building the backup MX server, which did some work catching and greylist filtering a bunch of the junk. I finally found some time and enabled greylist filtering. This slows down mail delivery slightly as the filter learns which host triplets are capable of properly queuing. So far it seems to be working. Please let me know if there are problems, or if you would like whitelist entries added.