Hi all, I've been having discussions with a customer of mine behind what is the best way to handle NDR and Backscatter spam. We're under the impression that :blackhole: will not return anything to the potentially faked from address and thus would help the NDR and backscatter problem. But, from what I read, many people suggest that :fail: is the right (or better) way to handle this. Would someone be able to explain how or why :fail: would be better, since it does generate a failure or bounce message? Thanks!