As we all know, MX records have a priority number, and mail senders are supposed to try the highest priority/lowest number servers first, then fall back to the lower priority.
I understand why secondary MX made sense in the 1980s, when the net was flakier, there was a lot of dialup, and there were hosts that only connected for a few hours or even a few minutes a day. But now, in 2020, is there a point to secondary servers? Mail servers are online all the time, and if they fail for a few minutes or hours, the client servers will queue and retry when they come back. Secondary servers are a famous source of spam leaks, since they generally don't know the set of valid mailboxes and often don't keep their filtering in sync? What purpose do they serve now? R's, John PS: I understand the point of multiple MX with the same priority for load balancing. The question is what's the point of a high priorty server that's always up, and a lower priority server that's, I dunno, probably always up, too. _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
