TB must have addons
About this Collection
13 Add-ons in this Collection
Adds some tools to import and export folders and messages
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.
Allows bidirectional access to Google Calendar
OpenPGP message encryption and authentication for Thunderbird and SeaMonkey.
Search and remove messages which are the same as other messages in your mail folders (referred to as duplicates or dupes).
Extracts all attachments from selected messages and then can delete, detach or mark-read.
Check the message contents and addresses before you send the message...
Reports compatibility issues for legacy extensions. This extension has been discontinued, since the new WebExtensions API is designed for stronger forward compatibility.
Adds many new mail filter actions - launch a file, suppress notification, remove star or tag, mark replied or unread, copy as "read", append text to subject.
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.