Just as a side note, I am using the Session app right now for secure short messages. Probably the most secure out there right now.
For email, I use Tutanota. Tutanota to Tutanota user, it is 100% secure and encrypted. For Tutanota to user without a Tutanota account, the non-Tutanota can open the msg with a predetermined and agreed on password. Boy o' boy, that was a mouthful.
Rule number one, unless you use a OTP encryption it ain't encrypted no matter what encrypted app you use. The only thing you are doing is making more work for "them". Which I am happy to do no-matter how time consuming it is.