i'm from germany and try to explain my exchange problem.
First i will tell you some about my environment.
2x DC running on W2K16
2x Exchange 2016 running on W2K16 in a DAG
I want use our Proxmox Mailgateway as smarthost.
When I enter the IP of the smarthost, everything is fine.
But i want use the FQDN because this name will be used soon in about 20 exchange servers.
There will be an error in exchange queue:
26.02.2018 15:01:27 - Server at mailrelay.mydomain.int returned '451 4.4.0 DNS query failed. The error was: SMTPSEND.DNS.NonExistentDomain; nonexistent domain mailrelay.mydomain.int -> DnsDomainDoesNotExist: InfoDomainNonexistent'
In cmd console on exchange and dc i can use nslookup and the result is ok.
Why can't the exchange resolve the FQDN when i use them as sent connector?
Where can I look for errors execpt the event log?
I hope you can help me :-)