Installing Your S/MIME Certificate into Thunderbird

From this point on the instructions will assume that you have applied for, been granted, and have downloaded a certificate file (client-certificate.p12). Be sure to back up the file from Firefox in order to be able to import it into Thunderbird (no. 6 below). In Firefox, under Tools > to Options > Advanced > Encryption tab > View Certificates > Highlight the most recent Trusted Device > Click Backup > Click OK.

  1. Open Thunderbird
  2. From within Thunderbird select Options from the Tools menu (or Preferences from the Thunderbird menu if you are using Mac OS X)
    NOTE: If you have already configured a master password in Thunderbird, skip to Step 5.
  3. Click the Privacy tab; click the Passwords sub-tab; click Change Master Passwordbutton
  4. Enter the password, confirm it, and click the OK button.
    NOTE: Use the password quality meter to ensure that this is a good quality.
  5. Click the Advanced tab; click the Certificates sub-tab; click View Certificatesbutton
  6. Under the your certificates tab click the Import button
    NOTE: If you have certificates that have expired DO NOT delete them. If you do you will not be able to view messages that were encrypted using them.
  7. Browse and locate the certificate bundle file (.p12 file).
  8. When prompted, enter your master password and click the OK button
  9. At the next password prompt, enter the password you chose in step 13 of the request process and click the OK button.
  10. You will be presented with a notice that your certificate has been successfully restored. Click the OK button to close the window then click the OK buttons on the two remaining windows.
  11. You should now delete the .p12 file from your computer.