Importing and Using your Email or Personal Authentication certificate with Mozilla Thunderbird on a PC



Importing your Certificate into Mozilla Thunderbird:

  1. Open Thunderbird and then click 'Tools' > 'Options' > 'Advanced'.

  2. Click the 'Certificates' tab

    Optional - select Ask me every time under When a server requests my personal certificate.

    Doing this alerts you to the fact that a server has requested identity confirmation and enables you to select your Comodo Personal Authentication Certificate.

  3. Click the 'View Certificates' button.

  4. In the certificate manager interface, make sure the 'Your Certificates' tab is selected and click 'Import'.

  5. Navigate to the location of your PKCS12 certificate file and enter any necessary passwords.

    Once complete the certificate will appear and you will be able to digitally sign and encrypt e-mails.

  6. Click 'OK'.

That's it. You have successfully imported your Comodo Personal Authentication certificate into Mozilla Thunderbird.

Signing and Encrypting Mails

  • Signing an email ensures the recipient knows the email has come from you and informs them that it has not been modified in transit.

  • Encrypting an email ensures that only the recipient can read the email content and attachments.

Note: In order to encrypt mail, you must first have your recipient's email certificate in your certificate store. To obtain their certificate, you need to get your contact to send you a signed email. Upon receipt of the signed mail, their certificate will be automatically imported into your certificate store and you will be able to sign/encrypt mail to that person.

Assign the certificate

  1. Open Thunderbird then click 'Tools' > Account Settings'.

  2. In the Account Settings dialog box, select 'Security'.

  3. Click 'Select' beside the text box in the 'Digital Signing' area and select your Comodo Personal Authentication certificate from the list.

  4. Follow the same process for the 'Encryption' section, selecting the same certificate

  5. Click OK in the Account Settings interface to confirm your choice

Signing and encrypting individual mails

To sign an individual mail:

  1. Compose your email and attach files as usual.

  2. Click Security and choose Digitally Sign This Message.

  3. Click the Send.

To encrypt an individual mail:

  1. Compose your email and attach files as usual.

  2. Ensure you have your contacts' email certificate and you have assigned the certificate to their entry in your contacts area.

  3. Click Security and choose Encrypt This Message.

  4. Click the Send.

Signing and Encrypting all mails by default:

  1. Open Thunderbird then click 'Tools' > 'Account Settings'.

  2. In Account Settings, select 'Security'.

  3. Select the appropriate options in the 'Digital Signing' and 'Default Encryption Settings...' areas to sign and/or encrypt your mails by default.

  4. As a rule of thumb, many users choose to digitally sign by default but only encrypt when sending a message which requires confidentiality.

  5. Click 'OK'.

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