Dark Mail Technical Alliance
I don't think email encryption will ever be more widespread than it is today. People simply don't care, and even those few that can be convinced to use it will invariably do something that invalidates the whole exercise like bring their key to a public library, use it on their phone, resend the entire conversation in plain text accidentally, lose the key and generate a new one with you having no way to verify that it's not actually mitm, etc. All of this has happened to me.