"To use it, you'll first need to install GPG (also probably
available as a package for your distro), then the Enigmail plugin
(download it from the web site, then use the Tools-Addons menu and
click Install to find and install
"The next time you compose a message, click the OpenPGP button
to be asked if you wish to configure OpenPGP support for this
account identity, with various options available to set your
defaults."
