4.1 Extensions - HorlogeSkynet/thunderbird-user.js GitHub Wiki

Extension Source Main Purpose Notes
Cardbook Source Access radicale instance for contacts Thunderbird v102+ got a new address book with vCard support
Header Tools Lite Home Used to edit References to have correct Message-ID to maintain threading on mailing lists when not subscribed. Unmaintained and incompatible with Thunderbird 68.0+, however there is an alternative solution.
Lightning Source Calendars Thunderbird v78+ integrates Lightning
Markdown Here Source Write pretty HTML emails sometimes
Enigmail Source PGP Thunderbird v78+ includes built-in encryption
DKIM Verifier Source Verify DKIM signatures

Alternative solution

Borrowed from MozillaZine: Custom headers. Archive link 1, 2. Just in case it disappears.

  1. Check the value of: mail.identity.idX.useremail to determine which index number refers to your email account. ie Edit → Preferences → Advanced → General → Config Editor
  2. Set user_pref("mail.identity.id1.headers", "References, InReplyTo"); to create the custom headers.
  3. Change the custom headers, you could use a user.js for this.
  4. Set the values for References, you can use as many References as you like, just make sure they are separated with a new-line character and a space ie: \n . user_pref("mail.identity.id1.header.References", "References: <[email protected]>\n <[email protected]>");
  5. Set the In-Reply-To: ie user_pref("mail.identity.id1.header.InReplyTo", "In-Reply-To: <[email protected]>");
  6. Restart Thunderbird and send your email.
  7. Comment out the above set options in your user.js with /* */. Go back into about:config ie (Edit → Preferences → Advanced → General → Config Editor) and rightclick on the keys mail.identity.id1.headers, mail.identity.id1.header.References and mail.identity.id1.header.InReplyTo and click Reset. Do not set these values to anything else in a user.js, because it will interfere with Thunderbird's normal behavior when you click Reply on an email.

Installing extensions from AMO (ATN)

To allow smooth extensions install from AMO (https://addons.thunderbird.net/) with thunderbird user.js, you'll need to :

  • re-enable JavaScript (9230, javascript.enabled) ;
  • re-enable mozAddonManager API (4503, privacy.resistFingerprinting.block_mozAddonManager) ;
  • disable RFP, at least for addons.thunderbird.net (4505, privacy.resistFingerprinting.exemptedDomains).

If you are not configured this way, Thunderbird will download extensions as .XCF archives instead of properly installing them.
If you don't miss AMO integration, you can always download extensions before manually opening them using Add-ons and Themes > Manage Your Extensions (cog wheel) > Install Add-on From File....