Most Popular Extensions
Simple Locale Switcher Requires Restart
An easier management of the user interface language
'Classic Toolbar Buttons' add-on restores old toolbar button ui (known from Fx 4-7s small view, Fx 4-12s large view & Tb 5-14) for current Firefox, Thunderbird and Seamonkey versions.
Beta builds on versions page!
Firefox and Thunderbird extension to manage user preferences and user profile CA certificates using group policy
Color Folders Requires Restart
Color your Folder Treeview Icons!
Display Mail User Agent Requires Restart
Displays icon for user agent of received mails.
Font Finder Requires Restart
FontFinder is created for designers, developers and typographers. It allows a user to analyze the font information of any element on a page, copy any piece(s) of that information to the clipboard, and perform inline replacements to test new layouts.
Confirm-Address Requires Restart
Confirm E-mail address before sending mail
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.
"Restart" menu and button, with configurable shortcut key.
ProfileSwitcher Requires Restart
It adds some options to launch easily other profiles and the Profile Manager.
ShowIP Requires Restart
Show the IP address of the current page in the status bar. It also allows querying custom information services by IP (right click) and see location and avaiable vouchers for shopping sites. Additionally you can copy the IP address to the clipboard.
Folderpane Tools Requires Restart
Allows for customization of the folder pane. Accounts can be rearranged and the startup folder can be chosen.
QuickNote Requires Restart
A simple note-taking extension.
ThunderPEC Requires Restart
ThunderPEC semplifica la gestione della Posta Elettronica Certificata (PEC) e delle comunicazioni PCT e FatturaPA in Thunderbird.
Minimize On Start and Close Requires Restart
A remake of the MinimizeToTray-extension made to fit the Windows 7 taskbar. Instead of minimize the window to the tray it minimize it to the taskbar. It can minimize on startup, when the window is closed and/or when the esc key is pressed.
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!
Adds toolbar buttons to the customize toolbar window in several programs including Firefox, Thunderbird and SeaMonkey. Some of the buttons make commonly preformed actions quicker, others add new functionality.
AutoProxy Requires Restart
Are you concerned about your privacy? Or, are you blocked from some websites by a firewall? And, are you arming yourself with a proxy? In that case, AutoProxy is designed for you! A tool to help you use your proxy automatically & efficiently.
Thunderbird Message Filter Import/Export Enhanced Requires Restart
Thunderbird Message Filter Import/Export Enhanced is a compatibility port of Wind Li's add on.
Original add on here: https://addons.mozilla.org/en-US/thunderbird/addon/thunderbird-message-filter-imp/