Over the last few weeks I am no longer receiving acknowledgement for emails that I have submitted via MCST. I am running Outlook 2016 (x64), I understand it's not supported but did work in the past and according to Exchange the submission left our server.
The return emails don’t appear to be caught by our gateway filter nor MSME. Is it possible my email address was blacklisted?
I was planning to raise a ticket however MCST is not a selectable product.