Enabling PGP encryption on Mac OS X Sierra
brew install gnupg
Optional - Install GpgTools GUI
brew cask install gpgtools
Then open the GPG preference pane and enable beta builds to get the latest MacOSx Sierra-compatible release for Mac. Once installed you can manage keys using a GUI ‘GPG Keychain’.
The GUI should reduce trips to the command line.
My public key can be found here - once copied to your clipboard you can either add it to your keychain from the command line or if you have gpgtools installed, the helper service should suggest to add it to the keychain. Now any email sent to me will have a padlock symbol on the right of the subject field to indicate that it can be encrypted.1