If you need email encryption but PGP is too heavy for you, that the idea of Ciphermail.
This is a simple software by me. Free to use and distribute. Report the bug to me, I will be appreciate it.
Just copy the text below (including the header and footer) and decrypt it (the password is: password). You will get a welcome message.
-----BEGIN CIPHERMAIL MESSAGE-----
-----END CIPHERMAIL MESSAGE-----