GPG Mail
because your privacy is valuable...
The PGP plugin for Apple Mail.

Installation instructions

  1. You need these files

  2. Installing the packagesFirst install the GnuPG package and then the GPGMail package.

  3. Generating a keyAt the moment you need to do this in Terminal.app (Applications/Utilities/Terminal.app).
    Please see Doku on gnupg.org.