When this issue occurs, you may experience a connectivity issue. Additionally, the following events are logged in the Application Log:
Event id 4999:
Event id 1000:
Event id 7301:Event id 7036:
This is a known issue in Microsoft Exchange 2010 Information Store.
To fix this issue, install Update Rollup 11 for 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.