Most Popular Extensions
Confirm-Address Requires Restart
Confirm E-mail address before sending mail
Allows you to use your Exchange email accounts that use Outlook Web Access (OWA) with Thunderbird
ImportExportTools NG Requires Restart Featured
Adds tools to import/export messages and folders (NextGen)
Stationery Requires Restart
Extension to mimic Outlook Express Stationery.
Allow you to use HTML files as templates for mail. Also allow custom template in replies or forwarded mail!
QuickFolders (Tabbed Folders) Requires Restart Featured
The "Swiss army knife" of folders. Turn your favorites into tabs - open folders and subfolders, move mails without scrolling around or searching. powerful + easy.
See new mail at a glance after automatic filtering - supports quickFilters addon!
Thunderbird Conversations Requires Restart
This addon provides a conversation view for Thunderbird, grouping messages together and allowing you to reply "inline" thus providing a more efficient workflow.
ThunderPEC Requires Restart
ThunderPEC semplifica la gestione della Posta Elettronica Certificata (PEC) e delle comunicazioni PCT e FatturaPA in Thunderbird.
Lightning Calendar Tabs Requires Restart
Displays tabs which allows quick navigation between time periods in Lightning calendar. All views of calendar are supported. Color of tab texts can be adjusted.
XNote++ Requires Restart
Persistent sticky notes for Thunderbird associated to mails.
This is a port to Thunderbird >= 3 based on XNote 2.1.0 ( https://addons.mozilla.org/en-US/thunderbird/addon/3093 ) with bugfixes and additional features.
MinimizeToTray Reanimated Requires Restart
MinimizeToTray Reanimated is an application mainly dedicated to Thunderbird to allow its minimization in the systray in one click. It is the update of MinimizeToTray Revived, which is not maintained anymore since the recent versions of Thunderbird.
Add-on has now been discontinued, see below.
Adds the Google Calendar web interface in a new Thunderbird tab. Creating and viewing events works like in a browser (Firefox, Chrome, ...)
Fixed version (no 90 day timer till silent failure) of the popular "Theme Font & Size Changer for Thunderbird" addon
Flex Confirm Mail Requires Restart
Confirm mail address and attachments based on flexible rules.
Check and Send Requires Restart
Check the message contents and addresses before you send the message...
LookOut Requires Restart
LookOut is a plugin which allows Thunderbird to interface with Microsoft's mail tools by decoding metadata and attachments encapsulated/embedded in a TNEF encoded attachment (aka winmail.dat).
ExQuilla for Exchange Requires Restart Featured
Thunderbird email accounts connecting to Microsoft Exchange Web Services.
LightningButton Requires Restart
Toolbar-Buttons for Lightning; advances the feature to get rid of the tabbar.
Auto Resize Image Requires Restart
Resizer for inline and attachment images (JPEG, PNG, BMP and GIF image formats).
All platforms are supported (Windows, Linux and Macintosh).
Provider for Exchange ActiveSync Requires Restart
Add sync support for Exchange ActiveSync (EAS v2.5 & v14.0) accounts to TbSync