EMail encryption

[SkepticScott]

However, it requires a slight change to how someone uses Outlook

Uggh, Outlook, the security hole of choice of crackers everywhere.

have an e-mail "profile" saved on the cloud with settings, preferences, and saved keys, and sync them up with your e-mail client of choice when you install or reinstall the client software.

You are adding a requirement to trust the groups that have implemented the "cloud". As Bruce Schneier wrote, "There are two types of encryption: one that will prevent your sister from reading your diary and one that will prevent your government." If you're going to encrypt anything, you'd better be trying for the second type.