We needed to recover an item deleted on an SBS 2011 server with Exchange 2010 SP1.
When we opened ExFolders for Exchange SP1 we ended up with an error:
An error occurred while trying to establish a connection to the Exchange server.
Exception: The Active Directory user was not found.
A search for the error turned up the following:
The fix was to delete the CN=Servers container using ADSIEdit.msc:
First we closed ExFolders then performed the above edit.
We then opened ExFolders and were then able to recover the deleted item the user had accidentally removed in Outlook.
Note that this SBS 2011 was a migration from SBS 2003 R2.
Microsoft Small Business Specialists
Co-Author: SBS 2008 Blueprint Book