Up & Coming Extensions
This 15KB restartless add-on will add a "File" -> "Restart" menu item and a ctrl/cmd + alt + r hotkey to restart Firefox or Seamonkey.
Return Receipt Toolbar Button Requires Restart
Allow you to add a Return Receipt button to mail compose window toolbar.
Lightning Month Tabs Requires Restart
This addon adds month tabs into Lightning calendar month view
SmilieInserter Plus Requires Restart
Insert smilies in messages.
OutlookAlike BETA Requires Restart
Makes Thunderbird looking like Outlook.
Mnenhy Requires Restart
The primary goal of the Mnenhy project is to make some enhancements to SeaMonkey MailNews/Thunderbird, since there're still plenty of comfort functions missing if compared to Netscape 4.x and other mail and news clients.
Folder Filters Button Requires Restart
Just a very simple add-on that adds a toolbar button to execute the "Run Filters on Folders" from Tools menu.
Free/Busy Requires Restart
Publish free/busy calendar file (*.ifb) via ftp or to a file. View other people's free/busy info in meeting organizer window. Integrate Thunderbird and Outlook calendars without Exchange server.
Google Tasks Sync Requires Restart
Manage your tasks from Thunderbird, even while offline.
Track your shipment Requires Restart
Link to tracking sites. (mainly Japanese companies)
Muttator Requires Restart
Make Thunderbird behave like Vim
Account Colors Requires Restart
Associates user-defined colors with accounts and identities. Applies these colors to accounts, identities, folders, message list, message headers and compose headers. Users will always know which accounts/identities they are working with.
Exit Button Thunderbird Requires Restart
Adds a toolbar button to exit Thunderbird. Go to View menu, Toolbars, Customize... and drag the icon where you want...
Looks up the definition of words on a Web page.
Zombie Keys (Multilanguage Keyboard) Requires Restart
Enter accents, diacritics, diaeresis, umlauts, ligatures etc. with keyboards of various countries (us,uk,ie,fr,it,ru,de,sv) - via easy to remember shortcuts or menu. Also supports all textboxes of the application (such as search, filters).
Bird Import Requires Restart
The extension allows to import e-mail messages from The Bat! mail client into Thunderbird.
LocalFolder Requires Restart
Add as many local folders as you want to (like outlook PST).
NB. It doesn't import PST files.
OpenSearch Requires Restart
OpenSearch is a Mozilla Messaging addon that will allow you to search the web from within Thunderbird.
Email signature for Thunderbird - WiseStamp Requires Restart
Switch Thunderbird email signatures. Supports Gmail, Yahoo, AOL & Outlook webmails. Youtube, Facebook, Twitter icons & more