Though social media has reduced the need of sending emails but still for almost all professional reasons we send emails. Our emails are the online letters and contain useful information hence the information must be protected. In this article, we'll discuss how we can send encrypted emails in Linux
First, you must have an email client installed. There are many free and open source email clients available and you can install any one of them. I have written an article on free and open source email clients for Linux.
You have many options to choose an email client, but for this article, I’m going to use Thunderbird.
If you have ready your email client, we can start. We’re going to use enigmail to encrypt the emails. Enigmail is a security add-on for Thunderbird and Icedove to encrypt and digitally sign email. You can install it through the add-ons manager of thunderbird.
First, search enigmail in the add-ons manager.
Then click install.
Now wait until the installation is done.
You will see a message like this, then you must restart Thunderbird -
Then you must follow few steps to configure enigmail after installing it, you can check “The Enigmail Handbook” at - Enigmail Documentation
Also, you will need GnuPG, but it isn’t a problem because GPG is available for most Linux distros. When Enigmail is configuring, it generates keys using GPG, you should read the GPG documentation to understand the GPG encryption. Also, you must create a revocation certificate, please don’t forget it.
GnuPG mini-Howto: GPG Mini Howto
After that, you can write an email and encrypt it.
When you use GPG to encrypt, it uses a pair of keys. One is the private key and one is the public key. You must share your public key to allow the other people decrypt your emails or files, so you can send your public key to the receiver or upload it to a key server. You can do it through the key manager of enigmail, also you can see other options of GPG in the key manager.
Thunderbird isn’t the unique client that supports GPG, you can use other email clients, but the most important thing is that you should know the way GPG works.
You can use other alternatives like:
Evolution (Gnome): https://fedoraproject.org/wiki/Using_GPG_with_Evolution
You can use the email client that you prefer, but you must check the support for GnuPG and the support for your Linux distribution. I used Thunderbird for this tutorial because is most popular and easy to use. Also, it can be installed on any operating system including Linux, if you prefer other clients, please read the correspondent documentation before any action.