Hi guys
In our organization we have an Exchange Server 2013 CU6 with both server roles CAS and Mailbox installed (absolutely fresh deployment). Users from AD have successfully been assigned mailboxes. The authoritative domain of the server is set correctly to our local domain. The DNS MX record to the Exchange-host exists and works well (tested with nslookup and setting q=MX). For testing purposes all the receive connectors allow connections from anonymous users.
I've tried to send an SMTP mail via telnet connecting to CAS via port 25. The connection is established and the sender and receiver are accepted by the server but when I submit the message (line containing only a single a full stop) I get the error:
451 4.7.0 Temporary server error. Please try again later. PRX2
I have sent the same massage to the Transport Service on the Mailbox Server via port 2525 and the message was accepted, but it was not delivered to the mailbox of the recipient. Instead it just got stuck in a queue named "Mailbox Database ...". Its status is "Ready".
I have restarted all possible services and rebooted the system but that did not help. Do you have any idea what could be the matter? Thank you!
Cheers Dimitri