One of our customers has outsourced their mail to an IT services firm which apparently uses some kind of process to ensure "verification" and that the message is legit.
Our message fail on the error: "550-Verification failed for user XXX. 550-Previous (cached) verification failure 550 sender verify failed 550-verification failed for XXX
I called their outsource provider and they refused to say anything other than: "Call Microsoft and tell them your your email is not verified".
I asked if they are talking about SPF records, or DNS. They guy had no idea and just kept repeating the instructions to call microsoft or my ISP.
Any IDEA WHAT THIS IS ALL ABOUT?
We use exchange 2007 but use Mail Marshal in the DMZ to receive mail from the outside world, and ultimately to route exchange mail to the outside world.