We ahve a very baffling mail routing problem at the moment, whereby internet mail comes in to server A, destined for a user on server B. Both servers are clustered and in the same NNN. Some messages route fine, but others simply sit in the mailbox on server A. We have tried mail connection doc between the servers without success, but what is even stranger is that if your force a route from the server console, the messages transfer fine. ‘tell router show stats’ also recognises that these messages are pending for server B. They just won’t route on their own. Internal (NRPC) messages route fine. Very strange. Any help would be greatly appreciated.