Up & Coming Extensions
MinimizeToTray revived Requires Restart
Minimizes windows into the system tray.
Mail Redirect Requires Restart
Allow to redirect (a.k.a. "remail") mail messages to other recipients.
New Mail Attention Requires Restart
This addon calls attention to main window on new message arrival.
Extra Format Buttons Requires Restart
Adds a font size (in pixels), strikethough, subscript and superscript buttons to Thunderbird's Compose Window.
IMAP Received Date Requires Restart
Make the “Received” column in IMAP folders show when messages were actually received.
Copy Sent to Current Requires Restart
Allows to place a copy of sent messages (aka FCC) into the currently active folder or any other folder you choose, when you create the message. Usually the copies are placed into the 'Sent' folder. For replies, you may also move the original message.
Highlighter Requires Restart
Quickly highlight some text in Thunderbird message composing windows.
Lightning Nightly Updater (Unofficial) Requires Restart
Quickly get to the latest nightly build of Lightning relevant to the version of Thunderbird and the OS you're on.
Smiley Fixer Requires Restart
Fixes Wingding Smileys in Outlook-generated emails
Clean Subject Requires Restart
"Clean Subject" cleans the subject from multiple occurrences of subject prefixes such as ("Re: Re-2: Re:") and postfixes that are inserted by other clients. Words like "[SPAM]" can be cleaned as well. These prefixes can be defined in the preferences.
Dictionary Switcher Requires Restart
Toggles dictionaries automatically or manually and displays the currently selected one
Remember Mismatched Domains Requires Restart
The Remember Mismatched Domains extension for Firefox and Thunderbird adds a "Don't warn me again about this certificate for this domain" checkbox to the Domain Mismatch and Expired Certificate warning windows. When selected the domain...
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!
Google Hangouts Web Messenger brings Google Hangouts right into your browser to chat with your friends.
FireTray Requires Restart
A system tray extension for Linux and Windows, allowing to set up custom icon, hiding to tray instead of closing, display the number of unread messages in mailing applications, and other features ...
Quick Locale Switcher 2 Requires Restart
Allows you to quickly switch to a different language (User Interface, Spell Checker Dictionary and Website content) in your Mozilla application.
MR Tech Toolkit Requires Restart
(Formerly Local Install) The primary goal of this extension is to provide the tools needed to install and manage extensions and themes locally and tons of other features.
Note: With Toolkit 6.0 Auto Archiving is fully working in Firefox 2.0 and temp...
Simple Locale Switcher Requires Restart
An easier management of the user interface language
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. ...