When Microsoft Outlook Web App processes a certain pattern of text data in a Microsoft Exchange Server 2010 environment, a stack overflow exception occurs. Therefore, Outlook Web App crashes.
This issue occurs because the Exchange server recursively processes a certain text pattern.
To resolve this issue, install the following update rollup:
2866475 Description of Update Rollup 2 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.