When you perform an Active Directory search by using the Lightweight Directory Access Protocol (LDAP) in a Microsoft Exchange Server 2010 environment, the search does not work as expected.
To resolve this issue, install Exchange Server 2010 Service Pack 3 (SP3) on Exchange Server 2010 servers. For more information about Exchange Server 2010 SP3, click the following article number to view the article in the Microsoft Knowledge Base:
2808208 Description of Exchange Server 2010 Service Pack 3
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.