Up & Coming Extensions
Confirm mail address and attachments based on flexible rules.
Grammar Checker Requires Restart
Checks grammar using LanguageTool.
SmartTemplates offers an easy and powerful way to automatically create customized replies by auto-inserting various mail headers. Templates can be created for every mail identity, Stationery files can now be imported and used directly.
Hide Local Folders Requires Restart
Removes the "Local Folders" entry from the folder pane.
As of Firefox 33, Venkman *no longer works*, as the APIs which it needs have been removed.
Check the message contents and addresses before you send the message...
Auto Address Cleaner Requires Restart
Removes comment, display name automatically from addresses before sending mail.
Blinking Alert Requires Restart
Adds blink feature to the new-mail alert.
You can also disable auto-hiding of the alert.
List addons in Windows' "Add or Remove Programs".
Display Quota Requires Restart
This extension will display the current status of your IMAP quota in thunderbird's statusbar and will warn you when you reach a configurable limit...
Typical Reply Requires Restart
Provides ability to send/receive typical replies in a team.Provides ability to send/receive typical replies in a team.
Join-NG Requires Restart
Join partial messages. Somewhat similar to MS Outlook Express "combine and decode".
Color Folders Requires Restart
Color your Folder Treeview Icons!
DeepDark for Thunderbird Requires Restart
Dark mode for Thunderbird UI
ImportExportTools Requires Restart
Adds some tools to import and export folders and messages
Contacts Sidebar Requires Restart
Displays the address books in a sidebar in Thunderbirds 3-pane-window and can be toggled with the F4 key or a toolbar button.
Visit my Contacts Sidebar site for recent versions and news.
Copy Folder Requires Restart
The missing Thunderbird "copy folder" feature! Copy folders or entire POP/IMAP accounts recursively to any location while maintaining folder structure.
Auto Compress File Requires Restart
Compressor for attachment files. All platforms are supported (Windows, Linux and Macintosh).