Enigmail is an extension for the mail client of
Mozilla, Netscape 7.x, and Mozilla Thunderbird that allows users to access the authentication and encryption features provided by the popular GnuPG software. It can encrypt/sign mail when sending, decrypt/authenticate received mail, and import/export public keys. It supports both the inline PGP format and the PGP/MIME format, which can be used to encrypt attachments, and is cross-platform, although binaries are supplied only for a limited number of platforms. Enigmail uses inter-process communication to execute GPG to carry out encryption/authentication.
