Please see the other comments to find lots of real world examples of people sending unencrypted e-mail via their ISP without knowing about it. These are the aud

Please see the other comments to find lots of real world examples of people sending unencrypted e-mail via their ISP without knowing about it. These are the audience for these kinds of ideas, not people that already have PGP installed. I don't see where you got that idea from?