Article ID: 978777 - View products that this article applies to.
Consider the following scenario:
The set of folders could not be opened.
The information store could not be opened.
Additionally, you receive the following error message when you send an e-mail message by using Outlook 2003:
Unable to display the folder. The information store could not be opened.
Task 'Microsoft Exchange Server - Sending' reported error (0x800C8100): 'Unknown Error 0x800c8100'
The issue that is described in the "Symptoms" section occurs when your primary mailbox is hosted on an Exchange Server 2007 Service Pack 2 (SP2) server.
To resolve this problem, install the following update rollup:
(https://support.microsoft.com/kb/972076/ )Description of Update Rollup 2 for Exchange Server 2007 Service Pack 2
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 978777 - Last Review: May 15, 2010 - Revision: 2.0