We appear to be having a bit of an issue with our Exchange 2000 server. All of a sudden messages are not going form our exchange server to our relay server. They are sitting in microsoft Exchange queue under "unreachable destination".
If the server is rebooted then this allows for the messages to go through. but it appears to stop again at a random period of time later. There appears to be nothing changed on either the Exchange system or the relay server in the DMZ.
Anyone else experienced this or have any ideas of what i can do to try and fix it?