We have recently setup a Shared SMTP Namespace as an Internal relay domain with another AD site.
If any emails cannot be delivered to their site, they are routed here for delivery. if the mails cannot be delivered locally, then it is my understanding that a flag is added to the message header to prevent a loop.
In our case, it appears these mails are moved to the poison message queue. Can anyone shed any light on why this happens?
Thanks in advance