Let me start by saying this is the weirdest issue I have ran into that I have not been able to resolve without taking drastic measures.

Synopsis of the issue:

A single user calls stating that the mailboxes that she has full access to are no longer showing up and free/busy searches are no longer working and in testing OOF is not working either. As a part of troubleshooting the issue I delete and attempt to recreate the users mail profile (No Dice acts like auto discover fails or the mailbox cannot be found) , run a test of autodiscover from the Outlook client it failes with the error code of 0x800C8203. Additionally I test Autodiscover via the test-outlookwebservices cmdlet it test fine but when the cmdlet is run adding the -Identity option with the users email address I get the following error Autodiscover returned the error: 603:The Active Directory user wasn't found. After a quick google search I was able to find a somewhat simple yet painful fix of deleting the AD account and reconnecting the mailbox, at this point I was willing to try anything. So I disconnected the mailbox from the user, deleted the AD account then recreate the AD and reconnect the mailbox and like magic everything was working as it should.

Should any one reading this post know of a better solution the killing the AD account please feel free to leave a comment below with the fix.

-Till next time