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:
Then, when you click the message, only one search result is returned.
To resolve this issue, install the following update rollup:
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.