Not technically. You'd just have to apply encryption at a higher level
Send email bodies encrypted to base64 along with a public key fingerprint, then receiver's client would decrypt if it had the private key for that fingerprint
But this isn't compelling enough to get a network effect to topple in-browser gmail
Send email bodies encrypted to base64 along with a public key fingerprint, then receiver's client would decrypt if it had the private key for that fingerprint
But this isn't compelling enough to get a network effect to topple in-browser gmail