Assume that you apply Update Rollup 4 for Exchange Server 2010 Service Pack 2 (SP2) in a Microsoft Exchange Server 2010 environment. When you search for email messages in a Microsoft Outlook 2010 or Outlook 2013 mailbox in online mode, you receive the following message:
Your search returned a large number of results. Narrow your search, or click here to view all results
Then, when you click the message, only one search result is returned.
To resolve this issue, install the following update rollup:
2756485 Description of Update Rollup 4 Version 2 for Exchange Server 2010 Service Pack 2
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.