The folks here at Dissidentstoolbox.com are users of ProtonMail. After the discovery this year that Yahoo was assisting the NSA in scanning their email database and that the NSA had “obtain[ed] communications that are processed by major technology companies like Google, Apple, Microsoft, and Yahoo,” we decided to move to an email provider that is encrypted and (because they are based in Switzerland) beyond the reach of United States Government subpoena power. According to their website, ProtonMail is a group of “scientists, engineers, and developers drawn together by a shared vision of protecting civil liberties online. This is why we created ProtonMail, an easy to use secure email service with built-in end-to-end encryption and state of the art security features. Our goal is to build an internet that respects privacy and is secure against cyberattacks.”
If you wish to securely communicate with someone and do not wish to mess with learning public/private key pair technologies, then you should both get ProtonMail accounts (it’s free!) and get at it. I have it on my desktop, portable machine, and smartphone.
Encryption Plug-Ins for Email Clients
In the past we have used GPG with Apple Mail using the free plug-in GPGMail. This client requires that both sender and receiver have GPG installed and have generated public and private keys. We’ll cover that very soon and provide links.
I have used the Enigmail Add-on in Thunderbird. It works just perfectly. Also requires sender and receiver to have GPG public and private keys.