Sending emails it is just like sending postcards, anyone who comes across them can read the content, if you find it too hard to use encryption software like PGP/GnuPG, you can resort to encrypt messages online on a website and send the encrypted text, or post it to Usenet, for the intended recipient to retrieve.
Online services to encrypt messages
Lockbin: A free service for sending private email message and files, the service has an integrated online form and you can send the encrypted email from their own website, messages are encrypted in the server using AES256bit and TLS encryption in transit.
Crypo: It contains multiple encryption algorithms, hashing methods and password generators, one of the most complete websites to encrypt data online with many options and well designed. Messages can be password protected and decrypted using the same form.
All of the free online encryption services above are free and do not require you to install any extra software in your computer, just an internet connection.
You may also use a compression program like PeaZip, 7Zip or BCArchive to send your encrypted message or file to someone without encryption software installed and with little knowledge of computers, this is very easy to use and free, just add a password when you compress the .txt file, your recipient will only have to enter a password to read it and it will not overwhelm them if they are not too computer savvy.