After you apply Update Rollup 5 for Microsoft Exchange Server 2010 Service Pack 3 (SP3) in your environment, you cannot install S/MIME controls in Outlook Web App through Internet Explorer 11. Additionally, the S/MIME option is not displayed on the Options page in Outlook Web App.
This issue occurs because Outlook Web App does not recognize Internet Explorer 11 as a browser that supports S/MIME controls.
To work around this issue, use Internet Explorer 11 in compatibility mode to access Outlook Web App. To do this, press F10 to display the menu bar, and then on the Tools menu in Internet Explorer 11, click Compatibility View settings. Then, add the Outlook Web App site to the list of sites to be viewed in compatibility view.
- When you use this workaround to access Outlook Web App, you receive the following error message the first time that you do this:To use S/MIME you must have Internet Explorer 7 or a later version. For more information, contact your Help desk.
To work around this issue, close Internet Explorer 11, reopen the page in compatibility mode, and then the S/MIME option will work as expected.
- When you use this workaround, Internet Explorer 11 saves your Compatibility View settings for the website. Every time that you access the Outlook Web App site, Compatibility View will be used. To turn off Compatibility View for a website, click the Compatibility View icon for that website. You can also add or remove specific websites from Compatibility View without accessing each website.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about loading Outlook Web App Premium in Internet Explorer 11, go to the following website:
Article ID: 2978645 - Last Review: Aug 26, 2014 - Revision: 1
Exchange Server 2010 Service Pack 3, Exchange Server 2010 Enterprise, Exchange Server 2010 Standard