A plugin for MozillaMail that provides support for GPG/PGP signing/verification and encryption/decryption.
See http://enigmail.mozdev.org/ for downloadable .xpi files. (Note - the plugin needs to be compiled with the same major version of gcc as your mozilla - RedHat 9 and other recent distributions use gcc 3, older ones use gcc 2).
4 pages link to EnigMail:
lib/main.php:944: Notice: PageInfo: Cannot find action page
lib/main.php:839: Notice: PageInfo: Unknown action
lib/plugin/WlugLicense.php:99: Warning: Invalid argument supplied for foreach()