Outgoing Message Format Requires Restart
Set the default outgoing message format to Auto-Detect, Plain Text Only, Rich Text (HTML) or Plain and Rich (HTML) Text.
Auto Compress File Requires Restart
Compressor for attachment files. All platforms are supported (Windows, Linux and Macintosh).
Disable DragAndDrop (Thunderbird) Requires Restart
A Thunderbird extension which disables drag and drop in the folder pane.
This extension prevents unintended folder movement.
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/
Free/Busy Requires Restart
Publish free/busy calendar file (*.ifb) via ftp or to a file. View other people's free/busy info in meeting organizer window. Integrate Thunderbird and Outlook calendars without Exchange server.
ImportExportTools Requires Restart
Adds some tools to import and export folders and messages
PrintingTools Requires Restart
Adds some options to print messages and addressbooks
Quicktext Requires Restart
Quicktext is an extension for Thunderbird that lets you create templates that can be easily inserted into your own emails.
WebDAV for Filelink Requires Restart
Adds the possibility to use a WebDAV store for Filelink. With this extension you can link attachments to a WebDAV service, for example as provided by Apache's mod_dav or some public services.
AutoConfiguration Hook Requires Restart
Provides ability to create E-mail accounts for specific ISP via the account creation wizard.
Extra Folder Columns Requires Restart
This extension is for those TB3 users who want the multiple-columns view that TB2 allowed
IMPORTANT: If you are using Thunderbird 38 or later, uninstall this addon. The functionality is in core now.
Send Filter Requires Restart
This add-on allows you run your message filters automatically on outgoing messages after sending. In other words, it's a outgoing filter for thunderbird and seamonkey.
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...
Return Receipt Toolbar Button Requires Restart
Allow you to add a Return Receipt button to mail compose window toolbar.
Force Addon Status Requires Restart
Provides ability to change status of specific addon (enabled/disabled).
Blinking Alert Requires Restart
Adds blink feature to the new-mail alert.
You can also disable auto-hiding of the alert.
withAttach Requires Restart
This extension adds a menu option (and a toolbar button) to compose an email "with attachments"...