Folders and Filters
Archive This Requires Restart
Provides keyboard shortcuts for filing messages into nine configurable "favorite" folders using user-defined keys. Also provides a simple filter system with a keyboard shortcut to file the currently selected message(s) into the correct folder.
Automatically do Archive/Copy/Delete/Move actions based on user defined rules
CapsKiller Requires Restart
Caps Killer is a protection against newbies using caps in their mails.
Collapsed Unread Requires Restart
Shows unread email count for collapsed folders even if the unread mails are in subfolders.
Color Folders Requires Restart
Color your Folder Treeview Icons!
Count Filters Requires Restart
This add-on provides various search filters couting values, such as total number of recipients, or number of lines, words,links in body message.
Delete Only Empty Folder Requires Restart
Disallows to delete not-empty mail folders.
EmailPicky 4 Requires Restart
Grab email addresses from emails from any selected Email Folder and add them to your contacts. (Email Crawler / Email ID Grabber / Bounced email collector) - Thunderbird Plugin
Note: It doesn't create duplicates, but shows as 'xxx messages added'.
Empty 'em Requires Restart
Empty all your Trash and Junk folders in one fell swoop!
EuropeanMX Spam Reporter Requires Restart
Train your EuropeanMX filter by reporting unrecognized spam or false-positives back to us.
Expression Search / GMailUI Requires Restart
Powerful message searching through expressions. Type "from:fred to:tom" to see all messages from Fred to Tom in the current view. Support 'regular expressions' and 'click to search'.
This addon extends filtering to read messages downloaded during an IMAP synchronization (bug 308148)
Synchronize your favorite RSS sources with Thundebird and Feedly
Folder Levels Requires Restart
Rank your email folders by how much you care about them, and hide the ones you don't need right now.
Folder Pane View Switcher Requires Restart
Add arrow buttons for rotating among folder views, and switch to "All Folders" view when hovering over the folder pane during drag & drop.
folderplus Requires Restart
This extension adds some basic missing features about folders.
Move mails to their conversation folder. Navigate to folder with new keyboard shortcuts.
Gravatars Requires Restart
Show a column with the Gravatar-picture and sender-name in email folders.
Hide Local Folders Requires Restart
Removes the "Local Folders" entry from the folder pane.
IMAP Draft Unread Requires Restart
This is a Thunderbird addon that lets you customize the behavior of the IMAP draft unread messages. No more new mail notifications for your drafts!!