Managing Exchange Server 2007 is easy but sometimes you still encounter new problem. I've got one today so I'm sharing this to everyone.

Creating a new mailbox in Exchange 2007. I got this error: "An Exchange 2007 server on which an address list service is active cannot be found"

Resolution:
Go to Control Panel, Services.
Check your Exchange Server System Attendant service.
Check the status, this should be Started. If not, just double click then start the service.

This should fix this issue.