How to encrypt email with PGP & Enigmail

Table of Contents

Thunderbird or Mailvelope or standalone?

Your first choice is between using encryption with Thunderbird as a standalone email client, or installing Mailvelope as a plugin for Firefox or Chrome to use with webmail such as Gmail or Yahoo mail. If you're only accustomed to using webmail, then configuring and learning Thunderbird may be extra up-front work, and you may prefer to just install the Mailvelope plugin. But once you get it all set up, encryption is more transparent and easier to use in Thunderbird.

Mailvelope

This guide does not yet cover Mailvelope installation. You can watch a short video tutorial or visit the Mailvelope website for more information.

GPG4USB

Another option is a standalone utility called GPG4USB. Though it requires copy and pasting to encrypt and decrypt messages, it's easier to set up and can be used on any computer via a portable USB drive. Go straight to the project page, or read a tutorial.

Thunderbird

Thunderbird Prerequisites

Before configuring encryption, you must install:

  1. Thunderbird: If you already have it installed, make sure it's the latest version by going to Help->About Thunderbird. Configure Thunderbird with one or more of your mail accounts - it should provide an easy wizard. If you have any trouble, visit Mozilla's guide to manual configuration.
  2. GPG (GNU Privacy Guard)
    • Windows: download and install the latest version. Any of the variants will work; "Vanilla" is the smallest. The default settings should be fine.
    • Mac OSX: download and install the latest version. The default settings should be fine.
    • Linux: install gnupg2 from your package manager.
  3. Enigmail: In Thunderbird, go to Tools->Add-ons. In the "Search all add-ons" box at upper right, search for Enigmail. If you don't see it, make sure the "Search" filter is set to "Available Add-ons", not "My Add-Ons". Install Enigmail. After restarting Thunderbird, you'll be prompted to configure Enigmail. See the next section.

Configure Enigmail for Thunderbird

Our following quick guide should get you up and running. For more details, you can read the Enigmail Handbook.

  1. After first installing the Enigmail Add-on and restarting Thunderbird, you'll get an option to configure Enigmail by clicking "Start setup now." Or, at any time after installing the Enigmail plugin, you can start Thunderbird and go to Enigmail->Setup Wizard.
  2. Pick "I prefer a standard configuration".
  3. Select the email account you want as your primary user - you can add others later.
  4. Generate a new key using the default options - be sure to use a strong passphrase, and be sure to remember it. Your key will be useless if you forget your passphrase.
  5. The key generation may take 10 minutes, or possibly even longer.
  6. When done generating the new key, it will offer you the option of creating your revocation certificate, which will allow you to mark your key as withdrawn in case you lose it or it is compromised in the future. Fill in the passphrase you just created, then save the file in a place you can access it even if you lose your computer, such as a USB drive stored somewhere else. Make sure no potential adversaries can access the file.
  7. Click "OK", "Next" and "Finish"
  8. To share your public key so that other people can easily download it and send encrypted messages to you:
    • In Thunderbird, go to Enigmail->Key Management.
    • Right-click on your key and pick "Upload public keys to keyserver"
  9. Important: to back up your private and public keys, to be able to read your encrypted email even if you lose your computer or hard drive data:
    • In Thunderbird, go to Enigmail->Key Management.
    • Right-click on your key and pick "Export Keys to File."
    • Pick "Export Secret Keys"
    • Save the file in a place you can access it even if you lose your computer, such as a USB drive stored somewhere else. Make sure no potential adversaries can access the file.

Now you can let people know you have encryption set up. They can download your key from the keyserver, or when you compose an email you can click "Attach My Public Key":

Reading Encrypted Emails

If someone sends you an email encrypted with your public key, when you open it in Thunderbird you will be prompted for your private key password. Once you enter it, you can read the email as usual.

You can tell Thunderbird to remember your password so you don't have to enter it every time:

  • In Thunderbird, go to Enigmail->Preferences
  • Set "Remember passphrase for ### minutes of idle time". For example, setting 120 will mean you're prompted if you read or send an encrypted email after 2 hours of not using encryption. (If you restart Thunderbird or your computer, you will have to enter the passphrase again.)

Encrypting Email

To send encrypted messages to someone else who has set up encryption, you must first import his or her public key. Once you have imported the key, you can compose a new email to the recipient, and it should be automatically encrypted.

Importing Keys

You only need to import each contact's key once. You can import in different ways, depending on how the contact has shared the key:

1. From a public keyserver

If the person has uploaded his or her key to a public keyserver:

  • In Thunderbird, go to Enigmail->Key Management
  • Go to Keyserver->Search For Keys
  • Enter the name or email address of someone you know who has encryption set up. and click OK.
    • If the system returns multiple keys for the same email address, it may be because the person lost the private key or forgot the passphrase, so had to generate a new keypair. But you should be especially careful to verify with the person that you download the correct key in case one or more of the keys is a fake.
  • Highlight the key you want, then click OK to import it.

2. From an email attachment

If the person sent you a key as an email attachment:

  • Save the received key to a temporary location
  • In Thunderbird, go to Enigmail->Key Management
  • Go to File->Import Key From File
  • Browse to the key and select it for importing

Verifying a Key

It is important to make sure you have the correct public key for people. An adversary could attempt to send you fake keys, to to trick you into sending emails the adversary can intercept and read. So, after you import someone's public key, you should verify it:

  • Have a conversation with the person ― ideally by phone or in person. If you're confident in setting it up, you could also use a secure online channel (an email exchange would not yet be secure, since you haven't verified the key!)
  • Both of you: in Thunderbird, go to Enigmail->Key Management
  • Both of you: double-click the person's key.
  • Read the Fingerprint value and make sure it's the same for both of you.
  • Once you're satisfied, you can sign the key to vouch that the key matches the owner:
    • In the window where you verified the Fingerprint, click "Select Action"
    • Choose "Sign Key"
      • Check "I have done very careful checking" if you know for sure the person is who he or she claims - for example, you have known the person well for years, or have checked a government ID.
      • Check "I have done casual checking" if you aren't sure of the person's identity
      • Click "OK"
  • Send the signed key to the owner:
    • Compose a new email to the owner
    • Go to Enigmail->Attach Public Key
    • Choose the person's key
    • Click "send"
    • Send the email
  • If the owner wants to make the signing information public, to build the web of trust, he or she should:
    • Save the received key to a temporary location
    • In Thunderbird, go to Enigmail->Key Management
    • Go to File->Import Key From File
    • Browse to the key and select it for importing
    • Once the key is imported locally, highlight his or her key and go to Keyserver->Upload public keys.

Setting Trust Levels

Optionally, you can set the degree to which you trust the other person to carefully verify Fingerprints and identities. This information is only stored locally; no one else will see what level of trust you have set. This is used by Enigmail to judge how much it should trust keys from strangers: if several people you trust have vouced for the strangers' keys, Enigmail will trust them.

  • In Thunderbird, go to Enigmail->Key Management
  • Double-click the person's key.
  • Click "Select action"
  • Pick "Set owner trust"
  • Set the trust level and click "OK"

Adding Identities

If you want to associate more than one email account with your keypair:

  • In Thunderbird, go to Enigmail->Key Management
  • Right-click your key and pick "Manage User IDs"
  • For each email address you want to add, click Add
    • fill in the identity name (your name, or perhaps an organization associated with the account)
    • fill in the email address
    • Click "OK"
  • Upload your public key to the keyserver
FaLang translation system by Faboba
Email icon
Subscribe
Get our latest news with email alerts from our International Newsletter, Blog, News Service, and individual chapters.

Subscribe

"DGR is our last, best hope."
-Dillon Thomson

”We need people from all walks of life doing all kinds of things to support this movement and perpetuate the mentality and actions of resistance.”
-Sam Leah

“The most pressing problem facing the world is the iron heel of civilization on the neck of human and non-human communities.”
-Max Wilbert

“I love the land where I live, where thick mists drift between trees and rocks and rain drips from moss and flows down mountainsides.”
-Max Wilbert

“Every kind of resource extraction is an act of domination and control and is a statement that says the way of life we have created for ourselves—the shiny, fast moving, plastic way of life—is more important than life itself.“
-Sam Leah

”If you are terrorized or mesmerized, you are not alive. Rejoin the living, join the resistance.”
-Jennifer Murnan

“DGR understands that resistance is not a monoculture and that everyone and every kind of action is needed.“
-Sam Leah

”Our allegiance lies with the real world, with real human beings and real forests, and we will fight to protect them.”
-Max Wilbert

"I don't think it is violence to defend that which you love."
-Saba Malik

“I love recognizing the ways in which wildness, no matter how thoroughly civilized a place may be, is constantly working and toiling. I love thinking about civilization falling away as that wild force eats through it.”
-Dillon Thomson

Meet DGR's Staff

Sun, Sep 26 2021
The IPCC Report: Key Findings and Radical Implications
This article originally appeared in Climate & Capitalism. Editor’s note: DGR has always argued that civilizations are inherently destructive and environmental destruction and degradation has been ongoing for millenia. Climate change is only another [...]

Continue Reading

Sat, Sep 25 2021
How to give the land back
This article originally appeared in Shareable. Featured image: A Wiyot man tends a fire in preparation of a candlelight vigil remembrance ceremony. Credit: Nick Adams By Aaron Fernando It’s common to feel a deep sense of injustice for what happened in [...]

Continue Reading

Fri, Sep 24 2021
2020 Was Deadliest-Ever Year for Environmental Defenders: Report
This article originally appeared in Common Dreams. Editor’s note: As it was last year and the year before that. The resistance grows stronger to late stage capitalism. The land destroyers are becoming more and more desperate as their power slips away. [...]

Continue Reading

Thu, Sep 23 2021
Standing Rock is Everywhere: The Indigenous Heart of the Climate Change Fight
This article originally appeared in Resilience. Editor’s note: In order for the planet to survive, we must act in its defense. We can not rely on governments or corporations to do it. This is why Deep Green Resistance is organizing actions to confront [...]

Continue Reading

Wed, Sep 22 2021
The Girls and the Grasses: A Celebration and Fundraiser for the Ecofeminist Movement
Global warming. Biodiversity collapse. Rampant inequality, war, and sexual abuse. The problems we face today are overwhelming and getting worse. Eco-feminism has answers. From the philosophy of domination to the practicalities of overpopulation, there are [...]

Continue Reading

Tue, Sep 21 2021
What are reforms?
Editor’s note: “this quote of James Connolly who was an Irish Republican around the early 1900s, active around the 1900s in the independence movement in Ireland, and James Conolly said revolution is never practical until the hour the revolution [...]

Continue Reading

Mon, Sep 20 2021
Totalitarianism of Today
“A really efficient totalitarian state would be one in which the all-powerful executive of political bosses and their army of managers control a population of slaves who do not have to be coerced, because they love their servitude.” – Aldous Huxley [...]

Continue Reading

Sun, Sep 19 2021
Robbing the Soil, 2: ‘Systematic theft of communal property’
This article originally appeared in Climate & Capitalism. It is part 2 of a series, read part 1 here. Featured image: Tenants harvest the landlord’s grain “The expropriation of the mass of the people from the soil forms the basis of the capitalist [...]

Continue Reading

Sat, Sep 18 2021
Robbing the Soil, 1: Commons and classes before capitalism
This article originally appeared in Climate & Capitalism. Featured image: Harvesting grain in the 1400s Editor’s note: We are no Marxists, but we find it important to look at history from the perspective of the usual people, the peasants, and the [...]

Continue Reading

Fri, Sep 17 2021
Beavers are back: here’s what this might mean for the UK’s wild spaces
This article originally appeared in The Conversation. Editor’s note: “That repair should be the main goal of the environmental movement. Unlike the Neverland of the Tilters’ solutions, we have the technology for prairie and forest restoration, [...]

Continue Reading

See All Stories