For this free service, Steganos uses an encryption standard AES 256 Bit. To use this service, you required a free account with them. (Steganos is known for its security products for quite some times now).
Just create an account, type in a new text or insert an existing text by pasting it into the text field, choose a password and click on "Start Steganos FreeCrypt". Your encrypted text will appear immediately. Now the encrypted text can be sent out via email.