I have started using PGP to encrypt/sign my email. It's relatively easy to set up and use. I have successfully set up my wife and mother with it for both email

I have started using PGP to encrypt/sign my email. It's relatively easy to set up and use. I have successfully set up my wife and mother with it for both email and xmpp, and am working on convincing my dad and brother to do the same. Take a look at Enigmail for Thunderbird and Psi for xmpp. Both work quite well and are reasonable to set up and use.