Extensions by Weekly Downloads
FlashGot Mass Downloader Requires Restart
Download all the links, movies and audio clips of a page at the maximum speed with a single click, using the most popular, lightweight and reliable external download managers.
Lightning Requires Restart
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.
ImportExportTools Requires Restart
Adds some tools to import and export folders and messages
Provider for Google Calendar Requires Restart
Allows bidirectional access to Google Calendar
SQLite Manager Requires Restart
Manage any SQLite database on your computer.
Auto Resize Image Requires Restart
Resizer for inline and attachment images (JPEG, PNG, BMP and GIF image formats).
All platforms are supported (Windows, Linux and Macintosh).
Enigmail Requires Restart Featured
OpenPGP message encryption and authentication for Thunderbird and SeaMonkey.
This add-on allows you to export your saved passwords and disabled login hosts using XML or CSV files that can be imported later.
Note: This add-on won't work in Firefox 57. It may eventually if the APIs to access passwords are implemented.
Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.
If you are the kind of person who likes to have total control over every aspect of your downloads, "Download Status Bar" is the add-on you are looking for.
CardBook Requires Restart Featured
UnMHT allows you to view MHT (MHTML) web archive format files, and save complete web pages, including text and graphics, into a single MHT file in Firefox/SeaMonkey.
gContactSync Requires Restart
Synchronizes contacts & groups between Thunderbird or SeaMonkey and Google Contacts. Imports Facebook friends, contacts you follow on Twitter, and more.
ReminderFox Requires Restart
ReminderFox displays and manages lists of reminders and ToDo's. ReminderFox makes sure you remember all of your important dates via easy-to-use lists, alerts, and alarms, right in your browser without the need for a separate calendar program.
QuickNote Requires Restart
A simple note-taking extension.
Manually sort folders Requires Restart
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.
Mail Merge Requires Restart Featured
Mass Mail and Personal Mail
AutoProxy Requires Restart
Are you concerned about your privacy? Or, are you blocked from some websites by a firewall? And, are you arming yourself with a proxy? In that case, AutoProxy is designed for you! A tool to help you use your proxy automatically & efficiently.
MinimizeToTray revived Requires Restart
Minimizes windows into the system tray.
Send Later Requires Restart
True "Send Later" functionality to schedule the time for sending an email.