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.
ProtectedText: All encryption is done in your browser with JavaScript, the password is never sent to the server, and just in case you don´t trust the website, the source code used to encrypt is open source. There is no registration, logging or tracking and an easy to remember URL to access the encrypted note is available.
Cypher Dog: This is mostly a paid product, decryption works for free but after two weeks trial you must pay to encrypt messages. It can be used in your desktop computer, smartphone or browser installing an extension, it is a scalable and business friendly solution for encryption.
Encrypt-Online: An easy to use form allows you encrypt any text message password protecting it, data is encrypted in the browser with JavaScript, you can choose in between the algorithms AES256 bit in CBC mode or 3DES, they are both uncrackable. There is a single advertising banner in the website that finances its operation.
SecureStuff: This website allows you to encrypt files and text, operation is very easy, there are two windows, enter the text in one of them and you will see the encrypted text in the other window where you can copy and paste it transmitting the decryption password to the recipient by secure means such as a phone call.
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, simply 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.