Add-ons extend Thunderbird’s functionality, making it the one of the most extensible mail clients available.
Add-ons are third-party creations that in some cases have contained insecure or even malicious code, so install only those from sources you trust. Additionally, too many add-ons or even a single poorly written one can bring Thunderbird to its knees, so promptly uninstall any you do not need.
The canonical method to search for add-ons is from within Thunderbird (Menu Button – Add-ons – Get Add-ons). I find Thunderbird’s built-in web browser to be clumsy and the built-in search to provide poor results, so I prefer browsing the collection from a web browser. After finding what I want, I open it in Thunderbird’s built-in browser, entering its name into the “Search all add-ons” field at the top of the viewport. Once open in Thunderbird’s browser, press the “Add to Thunderbird” button.
I currently use:
- Automatic Dictionary Switching
- Contact Tabs
- Display Quota
- FireTray (Linux only)
- Send Later
- Show InOut
Address book synchronization add-ons are considered separately.
I’ve stopped using:
- Display Contact Photo works but isn’t something I need.
- Select Address Book Text works great, but the Contact Tabs add-on makes it unnecessary.
- TrackerBird was bundled with Thunderbird on openSUSE 12.3. I find no documentation, and a web search finds only problems that were solved by disabling it, so I decided to be proactive and shut it down.
These notes refer to Thunderbird 31.2 on Linux and were last updated 22 November 2014.