Most Popular Extensions
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.
'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!
Reinstates the extensions.checkCompatibility preference without respect to the current application version.
Diagnostics tool for Adblock Plus, provides some insight into internal processes of Adblock Plus.
Google Contacts Requires Restart
Access to Google contacts and synchronize them with Thunderbird address books.
AttachmentExtractor Requires Restart
Extracts all attachments from selected messages and then can delete, detach or mark-read.
SmoothWheel Requires Restart
Scrolls the page smoothly when scrolling the mouse wheel (or keyboard arrows if enabled).
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.
Mail Redirect Requires Restart Featured
Allow to redirect (a.k.a. "remail") mail messages to other recipients.
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 ...
新同文堂 (New Tong Wen Tang) Requires Restart
NewTongWenTang is a tool to switch display Chinese content between traditional and simplified glyphs (中文繁簡體互轉工具)
Clippings Requires Restart
Save frequently-entered text for pasting later.
Display Mail User Agent Requires Restart
Displays icon for user agent of received mails.
Folderpane Tools Requires Restart
Allows for customization of the folder pane. Accounts can be rearranged and the startup folder can be chosen.
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!
Addressbooks Synchronizer Requires Restart
Synchronizes selected addressbooks with other instances of thunderbird
using ftp/webdav/imap servers
PrintingTools Requires Restart
Adds some options to print messages and addressbooks
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.