La liste des extensions que je trouve intéressantes et que je teste
Keep your favorite Extensions synced with all your computers.
Adds a summary of mail accounts and folders to replace the account central pane and the empty folder preview
Zoom in, zoom out, and reset zoom with one toolbar button. Works in the Compose window too.
When filing messages, a search box will show up allowing you to quickly enter the folder name you want to move to. The long description has info on how to use the extension
If no search term is entered, a list of recent folders will show up instead.
This add-on provides a follow-up email feature for Thunderbird.
BugzillaJS adds a number of features to Mozilla's Bugzilla. Keyboard shortcuts, quick file box, inline image/github previews, relative timestamps, gravatars and more. (All features are optional; contains almost all features Bugzilla Tweaks has)
Selects an identity based on the recipients list when sending an email
Multiple Addon Deactivator (M.A.D) is an addon that can (de)activate one, many or each addon at the same time
This extension adds some basic missing features about folders.
Move mails to their conversation folder. Navigate to folder with new keyboard shortcuts.
Email Bookmarks are here ! ... eMark your important emails.
Do you have an email that will need to revisit/attend later on ? Would you like to keep it handy and get it with a simple click ? Bookmark your important emails with the eMarks addon.
Fixes the Signature Stacking bug for Forwards/Replies.
Categorize combines advanced bookmarking and search with easy tab-management. It's a fresh approach! Say adios to confusing never-ending tags and complicated folders. Categorize organizes your web sites much faster and lets you access them in a snap.