I set up a new domain and a new Exchange 2016 server and noticed that no email is being delivered to any mailboxes. Whether from one user to the other on the exchange server, or whether external email is being sent in, all email is going to the Poison Queue. Why, and how can I stop this behavior?
Some steps I have taken:
- tested the domain at MXToolbox.com (comes up clean)
- tested the domain at https://testconnectivity.microsoft.com
and all tests come up clean
- tested from iPhone too, same result. Messages show up in "Sent" but nothing is being delivered.
- enabled logging on the send and receive connectors, then examined the logs. I see no errors.