Hi
We have a shared smtp namespace, where a thirdparty cloud service is responsible to route the emails to the correct location using routing tables.
Therefore the accepted domain is set to non authoritative.
Problem:
There was an error in the routing table, and emails where sent to the wrong server. Because this server didn't know these addresses he sent them back to the cloud service. The cloud service, of course, used the wrong routing table and sent the emails back to
the wrong exchange server --> Loop.
After some attempts the exchange server detected the loop, and deferred the message. One day later the wrong routing table was corrected. Now all these mails are vanished and the sender didn't receive NDRs.
1. question: What happened with these emails?
Normally the cloud service detects mailloops and send NDRs after 7 retries. But it seems, that the exchange server detected it earlier, but because the domain is non authoritative, no NDRs were sent.
2. question: Is it possible to configure the mailloop detection in Exchange?
The goal is that Exchange detects a mailloops only after lets say 8 attempts, so that the cloud service can send NDRs.
Regards
Peter
