Re: Hard to Resolve.
This issue came to light for us when we changes mail relays.
Mailboxes on our exchange servers appear to be unaffected.
Email from some application servers however, is.
One tool which isn't mentioned in the article is "Smart Network Data Services" : https://postmaster.live.com/snds
This is interesting data to see but not actually useful in rectifying the problem.
One application server sends two types of email,
-One goes to the Junk folder.
-The other is silently deleted.
We have logged a support call with that supplier to try to find out more.
Still working on the problem!
Biting the hand that feeds IT
