Recently Updated Extensions

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QuickFolders (Tabbed Folders) Requires Restart

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 (125)
20,287 users
Updated Oct. 16, 2018

Year view Requires Restart

Year view for calendar.

Rated 4 out of 5 stars (50)
3,187 users
Updated Oct. 13, 2018

Display Mail User Agent Requires Restart

Displays icon for user agent of received mails.

Rated 4 out of 5 stars (109)
24,932 users
Updated Oct. 13, 2018

Menu Wizard Requires Restart

Customize menus : Helps removing, moving and renaming menus and menu items
Colorize important menu for ease of use! (use Style (CSS))
Change or disable any of used keyboard shortcuts
Support: Firefox, Thunderbird and SeaMonkey

Rated 5 out of 5 stars (245)
101,750 users
Updated Oct. 11, 2018

quickFilters Requires Restart

Quickly generate mail filters on the fly, by dragging and dropping mails and analyzing their attributes. Create a filter in less than 10 seconds, it's as easy as: drag, click, click.

By popular demand, supports SORTING filters alphabetically.

Rated 5 out of 5 stars (35)
12,336 users
Updated Oct. 5, 2018

Tiny JavaScript Debugger

TinyJSD is a JavaScript debugger for privileged code running Mozilla products like Firefox, Thunderbird, SeaMonkey. It serves to debug the application as well as extensions written in JavaScript.

Rated 5 out of 5 stars (8)
12,602 users
Updated Oct. 5, 2018

Send Later Requires Restart

True "Send Later" functionality to schedule the time for sending an email.

Rated 5 out of 5 stars (120)
66,304 users
Updated Oct. 3, 2018

Mailbox Alert Requires Restart

Mailbox Alert allows you to specify, for each seperate mail folder, a message, sound and/or a system command that will be executed when new mail is found there. ...

Rated 4 out of 5 stars (112)
14,001 users
Updated Sept. 24, 2018

Awesome Auto Archive

Automatically do Archive/Copy/Delete/Move actions based on user defined rules

Rated 4 out of 5 stars (32)
7,118 users
Updated Sept. 24, 2018

Nostalgy Requires Restart

Keyboard shortcuts to change folder, move/copy messages, with folder name auto-completion.

Rated 5 out of 5 stars (152)
7,523 users
Updated Sept. 23, 2018

DOM Inspector Plus! [dm] Requires Restart

Improved DOM Inspector! [dm version]. Box Model new layout & more data, see screenshot!. Horizontal scroll for Dom-Tree, and some more.
Inspects the structure and properties of a window and its contents.

Rated 4 out of 5 stars (6)
303 users
Updated Sept. 23, 2018

QuoteCollapse Requires Restart

Collapse and expand quotes. Please see the extension homepage for further information.
Note that MozDev has shut down long ago (mailing list etc). Add-On homepage, source code and issue tracker are on GitHub, as linked on this page.

Rated 4 out of 5 stars (27)
5,187 users
Updated Sept. 23, 2018

Provider for Google Calendar Requires Restart

Allows bidirectional access to Google Calendar

Rated 4 out of 5 stars (1,015)
304,892 users
Updated Sept. 18, 2018

Identity Chooser Requires Restart

Identity Chooser helps you to always use the correct identity when composing a new email.

Rated 5 out of 5 stars (91)
7,552 users
Updated Aug. 31, 2018

Thunderbird Integration for JIRA Requires Restart

This is a plugin for Thunderbird 3.3+ which is able to create Atlassian Jira issues out of e-mails or add the content of an e-mail as a comment on an Jira issue.
It is not yet ready to be used in Thunderbird 60.x.

Rated 4 out of 5 stars (11)
303 users
Updated Aug. 31, 2018

AVIM Requires Restart

Vietnamese-language input method editor (IME). Type diacritics directly into any Web page, Web app, or dialog box. Convenient, comprehensive, secure.
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Bộ gõ tiếng Việt cho phép đặt dấu trực tiếp vào bất kỳ trang Web, ứng dụng Web, hộp thoại.

Rated 5 out of 5 stars (41)
1,110 users
Updated Aug. 31, 2018

Hyperactive

Scans hyperlinks in composed messages and alerts if one of the hyperlinks is broken.

Rated 4 out of 5 stars (1)
24 users
Updated Aug. 22, 2018

LookOut (fix version) 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).
Support: Thunderbird and SeaMonkey

Rated 4 out of 5 stars (28)
62,859 users
Updated Aug. 22, 2018

Flexible Identity Requires Restart

Selects an identity based on the recipients list when sending an email

Rated 4 out of 5 stars (29)
986 users
Updated Aug. 16, 2018

Enigmail Featured

OpenPGP message encryption and authentication for Thunderbird and SeaMonkey.

Rated 4 out of 5 stars (216)
129,278 users
Updated Aug. 5, 2018