Most Popular Extensions

Subscribe

Confirm-Address Requires Restart

Confirm E-mail address before sending mail

Rated 5 out of 5 stars (55)
28,491 users

DOM Inspector Requires Restart

DOM Inspector is a tool that can be used to inspect and edit the live DOM of any web document or XUL application. The DOM can be navigated using a two-paned window displaying a variety of different views on the document and all nodes within.

Rated 5 out of 5 stars (77)
26,766 users

Owl for Exchange

Allows you to use your Exchange email accounts that use Outlook Web Access (OWA) with Thunderbird

Rated 4 out of 5 stars (33)
25,453 users

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!

Rated 5 out of 5 stars (137)
23,260 users

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!

Rated 4 out of 5 stars (138)
23,147 users

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.

Rated 4 out of 5 stars (453)
21,984 users

ThunderPEC Requires Restart

ThunderPEC semplifica la gestione della Posta Elettronica Certificata (PEC) e delle comunicazioni PCT e FatturaPA in Thunderbird.

Rated 5 out of 5 stars (20)
21,937 users

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.

Rated 5 out of 5 stars (83)
21,673 users

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.

Rated 4 out of 5 stars (14)
21,466 users

Flex Confirm Mail Requires Restart

Confirm mail address and attachments based on flexible rules.

Rated 4 out of 5 stars (7)
19,347 users

Check and Send Requires Restart

Check the message contents and addresses before you send the message...

Rated 4 out of 5 stars (31)
19,154 users

Open Google Calendar

Adds the Google Calendar web interface in a new Thunderbird tab. Creating and viewing events works like in a browser (Firefox, Chrome, ...)

Rated 4 out of 5 stars (42)
19,084 users

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.

Rated 4 out of 5 stars (118)
18,792 users

Test Pilot for Thunderbird

Add-on has now been discontinued, see below.

Rated 1 out of 5 stars (15)
18,454 users

Theme Font & Size Changer (fixed)

Fixed version (no 90 day timer till silent failure) of the popular "Theme Font & Size Changer for Thunderbird" addon

Rated 4 out of 5 stars (50)
17,348 users

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).

Rated 4 out of 5 stars (156)
15,867 users

Provider for Exchange ActiveSync Requires Restart

Add sync support for Exchange ActiveSync (EAS v2.5 & v14.0) accounts to TbSync

Rated 5 out of 5 stars (9)
15,467 users

LightningButton Requires Restart

Toolbar-Buttons for Lightning; advances the feature to get rid of the tabbar.

Rated 4 out of 5 stars (19)
15,018 users

Display Mail User Agent Requires Restart

Displays icon for user agent of received mails.

Rated 4 out of 5 stars (111)
14,918 users

ExQuilla for Exchange Requires Restart Featured

Thunderbird email accounts connecting to Microsoft Exchange Web Services.

Rated 4 out of 5 stars (107)
14,847 users