Running Exchange 2007 SP2. We have multiple AD sites, each with their own Hub Transport servers and mailbox servers.
At the moment, if someone emails email@example.com (i.e. a invalid address within my domain), the sender is sent an NDR.
Does anyone know where it's set what sort of NDR's are sent back to the sender?
Our Security team wants us to look into sending NDR's for some sort of message rejection and not for others. I understand there can be several reasons a message is bounced back - mailbox too full, invalid address etc.