I have an Ex2013 CU 20. This machine works fine, but I want to mirgrate to Ex 2016. So I installed an Ex 2016 on a new Windows 2016.
Now there is a queue on the new server named "briefkasten". There are a few incoming mails in it an the state is repeat. "briefkasten" is a mailbox database on the Ex2013. Obviously the Ex2016 is trying to deliver Mails to a database on the ex2013 server.
There is a error message:
05.06.2018 12:22:23 - Server at briefkasten returned '451 4.4.0 DNS query failed. The error was: SMTPSEND.DNS.NonExistentDomain; nonexistent domain briefkasten -> DnsDomainDoesNotExist: InfoDomainNonexistent'
I guess Ex2016 is trying to resolve "briefkasten", but it is not a server!
How to fix this? Which information do you need?