Keeping the contents of Email messages private is a very important practice in E-commerce, especially if the Email messages could contain personal information such as credit card numbers for your customers. While using secure protocols to check and send Email messages helps protect this information, the best protection is to encrypt the Email message itself.
There are two excellent tools for encrypting the contents of your Email messages. Pretty Good Privacy (PGP) is a well known and frequently used tool for encrypting Email messages. PGP Formmail is designed to use PGP when sending Email messages from Web based forms. GNU Privacy Guard (GnuPG) is an open source and free alternative to PGP.