Sending Encrypted Emails and Importing PGP Keys in Mozilla Thunderbird

OpenPGP encryption allows you to securely exchange email messages by encrypting their contents so that only the intended recipient can read them.

Before encrypted communication can take place, both parties must exchange their public keys.

Contents

• Sharing Your Public Key
• Sending an Encrypted Email
• Importing a PGP Key

Sharing Your Public Key

Before someone can send you encrypted messages, they need your public key.

To send your public key using Mozilla Thunderbird:

1. Open Thunderbird.
2. Create a new email message.
3. From the menu, select:

Security → OpenPGP → Attach My Public Key

4. Address the message to the person you want to communicate with.
5. Send the message.

The recipient will receive your public key as an attachment and can import it into their email client.

Important

When sending your public key, do not enable the option:

Digitally Sign This Message

The purpose of this message is only to distribute your public key.

Sending an Encrypted Email

Once your recipient has imported your public key and you have imported theirs, you can begin exchanging encrypted messages.

To send an encrypted email:

1. Create a new message in Thunderbird.
2. Click:

Security

3. Enable:

Digitally Sign This Message

4. Thunderbird will automatically detect that encryption is available for the recipient.
5. Compose and send your message.

When encryption is active, Thunderbird displays a confirmation indicator showing that the message will be encrypted before transmission.

Only recipients with the corresponding private key will be able to read the message.

Importing a PGP Key

When someone sends you their public key, it typically arrives as an email attachment.

To import the key:

1. Open the email containing the public key attachment.
2. Click the attached key file.
3. Select:

Import OpenPGP Key

4. Thunderbird will analyze the file and display information about the key.
5. Review the details if desired.
6. Click:

Import

to add the key to your keyring.

Once imported successfully, Thunderbird can use the key to:

• Encrypt messages sent to that recipient.
• Verify digital signatures created by that recipient.

How OpenPGP Works

OpenPGP uses two keys:

Public Key

The public key is shared with other people and allows them to:

• Encrypt messages sent to you.
• Verify your digital signatures.

Private Key

The private key remains on your device and should never be shared.

It is used to:

• Decrypt messages sent to you.
• Create digital signatures.

Anyone who obtains your private key may be able to read your encrypted messages and impersonate you.

Best Practices

• Always protect your private key with a strong password.
• Never send your private key to anyone.
• Verify key fingerprints before exchanging sensitive information.
• Keep backups of your OpenPGP keys in a secure location.
• Remove outdated or unused keys when appropriate.

Summary

OpenPGP encryption in Mozilla Thunderbird allows you to exchange secure email messages using public-key cryptography.

The process consists of:

1. Sharing your public key with your contacts.
2. Importing their public keys.
3. Sending encrypted and digitally signed messages.

When configured correctly, OpenPGP helps protect email communications from unauthorized access and verifies the authenticity of message senders.