Jeroen Geilman put forth on 10/21/2010 4:33 PM: > Yup. > > reject_unknown_client_hostname is fine for MXen and large providers, but > it will hurt simple relaying with many false positives.
There are thousands upon thousands of web forum servers that will fall victim to reject_unknown_client_hostname due to DNS mismatches when attempting to send thread reply notifications and the like. I've tried using this setting on multiple occasions over the past 5 years and it simply causes way too many ham rejections. The last time I tried it was rejecting replies from the Hotmail abuse servers after I'd sent some spam reports. There are simply too many legitimate players around the world who still don't setup proper DNS, due to ignorance, laziness, etc. There are plenty of anti spam methods available that can get you to blocking 99%+ of your inbound spam load without resorting to this test that blocks much ham. -- Stan
