After you apply either Update Rollup 3 or Update Rollup 4 for Microsoft Exchange Server 2010 Service Pack 3, you experience one of the following symptoms.
You open a folder in Microsoft Outlook in online mode. On the View tab in the Arrangement group, you select Categories. After you make this change, you cannot see any new email messages in the folder.
You select Public Folder in Outlook in cached mode. On the View tab in the Arrangement group, you select Categories. After you make this change, you cannot see any immediate updates of your actions. For example, you cannot see any follow-up flags that you assigned to an email message.
This problem occurs when the system processes table notifications for messages that involve multivalued properties, such as Categories. The system detects an inconsistency in the columns between the server state and the client state. Then it stops processing more table view notifications.
To resolve this issue, install the following update rollup:
2936871 Update Rollup 6 for Exchange Server 2010 Service Pack 3
To work around this problem when you sort messages by categories, you can update the folder view when you select a different folder view, such as Date (Conversations), and then return to the Categories view.
To work around this problem when it occurs only in online-mode in the Outlook client, you can use Outlook in cached mode. Or, if it is possible, you can use OWA to make the change to the folder view.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.