Blocks annoying video ads on YouTube, Facebook ads, banners and much more.
Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).
Organize your schedule and life's important events in a calendar that's fully integrated with your Thunderbird email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars.
This extension allows you to manually sort (order) your folders in the folder pane of Thunderbird or automatically sort them, but in a better way. This extension also allows you to re-order accounts in the folder pane.
Adds the Google Calendar web interface as a new tab directly into Thunderbird. Creating and viewing events works just as it would in a browser like Firefox
Search and remove messages which are the same as other messages in your mail folders (referred to as duplicates or dupes).
Allow to redirect (a.k.a. "bounce") mail messages to other recipients
Did your friend send you a cool link? Want to read the rest of that interesting article? Don't want to open up your web browser just to view it? You don't have to! Just view it in Thunderbird with ThunderBrowse!
Add symbol in header plane to switch between compact and expanded view. Options to switch between one or two lines compact view, which buttons should be displayed in header pane. Linkify RSS subject. Optionally darkens header if message has focus.
Displays icon for user agent of received mails.
add icons to buttons/menus/anywhere (CuteMenus - Crystal SVG not required)
Display birthdays from the Thunderbird addressbooks as events in Lightning.
Note from Mozilla: This add-on has been discontinued. Try MinimizeToTray Revived instead.
Minimize applications to the system tray.