Q: Smart Card S/MIME with Exchange 2013 I have an Exchange 2013 environment that I'm trying to implement S/MIME with smart cards.  To the best of my knowledge, and the little help I have received on TechNet, I have configured my Exchange server correctly.  I have installed the S/MIME controls on a Windows computer, I am able to log into OWA with a smart card, but when I try to sign an email or tell OWA which certificate to choose for digital signatures, nothing happens.
Has anyone successfully signed or encrypted an email using a smart card with OWA 2013, or have any ideas about what might be causing this problem?

A: I found the problem.  First, the Signing cert was missing Email Protection EKU.  Second, the emails need to be sent as plain text.  I have yet to find the document that states the users emails must be sent as plain text for this to work in a browser, so if somebody comes across it, please enlighten me.
