Return the privacy to day-to-day email communication and make it as popular as possible. Make it de-facto standard. Private conversations are not for everybody and encryption makes the body of your private email unreadable on its transit for any third party. Even if the message created for you is not encrypted (for any reason), we'll make this job for you, so your whole Inbox will be readable by you and by you only (unless your private key(s) are compromised).
There is no reason to re-invent the bicycle regarding encryption standards, OpenPGP (Pretty Good Privacy) makes its job really well and with proper key size its (still) unbreakable. Unfortunately, PGP key management solutions from their very beginning till today are still tools developed 'by geeks and for geeks'. Our mission is to revamp it as 'by geeks, but for people'.