Add-ons
Most Popular Extensions
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Flexible Identity
Requires Restart
Selects an identity based on the recipients list when sending an email
Saved Password Editor
Requires Restart
Adds the ability to create and edit entries in the password manager.
ThunderBirthDay
Requires Restart
Display birthdays from the Thunderbird addressbooks as events in Lightning.
Folderpane Tools
Requires Restart
Allows for customization of the folder pane. Accounts can be rearranged and the startup folder can be chosen.
Image Zoom
SeaMonkey Debug and QA UI
Requires Restart
Provides Additional Debug and QA UI for SeaMonkey development and testing.
Theme Font & Size Changer for ThunderBird
Theme Font & Size Changer lets you change the global font size and font family used for the user interface in Firefox. Design your browser with your favorite font.
Disable Add-on Compatibility Checks
Reinstates the extensions.checkCompatibility preference without respect to the current application version.
User Agent Switcher
Requires Restart
The User Agent Switcher extension adds a menu and a toolbar button to switch the user agent of a browser.
Session Manager
Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.
Return Receipt Toolbar Button
Requires Restart
Allow you to add a Return Receipt button to mail compose window toolbar.
Easiest YouTube Video Downloader
This Addon simply adds a dropdown button that lets you download YouTube Videos in various Formats. Download YouTube Videos in FLV, 3GP, MP3, MP4, 720p, 1080p in a single click.
Cookies Exterminator
Auto delete cookies, localStorage and IndexedDB objects as soon as they become unused
Quote Colors
Requires Restart
Quote Colors allows you to select text and background colors of different quote levels which are applied when reading or printing mail/news messages. Additionally, you can choose between graphical and traditional plain text quoting display mode.
P7MON
Extra Format Buttons
Requires Restart
Adds a font size (in pixels), strikethough, subscript and superscript buttons to Thunderbird's Compose Window.
Kaskus Quick Reply+
Requires Restart
provide a quick reply feature, under circumstances capcay required
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