There are no items in any of the event logs or other indications on either server to diagnose what went wrong or where the error occurred or what the error was. I found a similar article where another used had the same problem, but I am unable to find that URL for reference.
I was escalated a call today from one of my team members whom had found a user whom had left the company and then rejoined.
Due to our Mailbox retention policy we still had the old mailbox within the store (with the AD Account Disabled and hidden from the Global Address List) – therefore their account had been re-enabled, unhidden and after the usual period of replication the mailbox sprang to life in the store.
So, I made the decision to upgrade my domain from Windows 2003 SP2 to Windows 2008 R2.
So, I installed a new server, joined it to the domain and promoted it to a domain controller.
So, my next venture will be to install Microsoft Exchange 2010 on a Windows 2008 R2 server and pull out my old Exchange 2003 server.