How do I install/use the new Certificate on my Android phone/email?

How do I install/use the new Certificate on my Android phone/email? It is working great on my Windows box. I have emailed it to myself on my phone and followed the default install options. But my Android email system wants me to create a private and public key. As I understand it those are already in the cert. I cannot find a way to make the Android email use the cert I already have.

Just to clarify - the cert IS installed via the Settings/OS. But I cannot find a way to use it in email.