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Using Thunderbird with GPG


  1. GPG (GNU Privacy Guard) from Windows, Mac OS, or UNIX
  2. Enigmail to allow signing, encrypting, and decrypting within Thunderbird:
    1. Download Enigmail:
      (Firefox users: control-click and choose "Save link as...") and verify the signature.
    2. Launch Thunderbird 2.0 and navigate to Tools -> Add-ons; click the "Install..." button. Select the file you downloaded, and restart Thunderbird.


  • When you select a message in Thunderbird for the first time, you'll be prompted to use the OpenPGP Setup Wizard to configure OpenPGP.
  • The Wizard will configure the following by default:
    • All messages will be PGP-signed.
    • Messages will be PGP-encrypted only for selected recipients.
    • Email to be composed in plain text (for improved compatibility).
  • After completing the OpenPGP Setup Wizard, OpenPGP may report the error: " gpg command line and output:,/usr/local/bin/gpg --charset utf8 --batch --no-tty --status-fd 2 -d,gpg: invalid armor header: >\n,gpg: invalid armor header: >\n


  • By default, all messages will be PGP-signed. That default can be changed under Tools -> Account Settings. Expand the section for your account, select OpenPGP Security, and change Message Composition Default Options as desired.
  • To encrypt a message, in the Compose window, pull down the OpenPGP menu and select "Encrypt Message"..
  • If a message is signed but you don't have the key, you will be prompted to download it from a keyserver. However, both keyservers tested failed (the query hung).
  • Before using a key you've downloaded, you should (at minimum) contact the recipient by phone or in person to verify that the specific key ID you found actually belongs to them. In the search results window, the key ID is the first item in the description, beginning with 0x and a series of 8 hexadecimal characters.


  • Testing was done in January 2009 with Thunderbird

Last updated: Thursday, April 9, 2009

Information Systems and Computing
University of Pennsylvania
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