Folders and Filters
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.
This addon adds an entry in the right-click menu which re-threads selected messages together (groups selected messages into the same thread)". This is done by _modifying_ messages; the author of the addon declines any responsibility for data loss.
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.
Tidybird Requires Restart
Organize email into folders quickly and easily.
Collapsed Unread Requires Restart
Shows unread email count for collapsed folders even if the unread mails are in subfolders.
CapsKiller Requires Restart
Caps Killer is a protection against newbies using caps in their mails.
SmartFilters Requires Restart
Tired of writing a lot of filters? Install SmartFilters now to organise your mailbox automatically. It can sort out your mailing lists and robot emails.
SavedSearchInSubFolders Requires Restart
This addon allows virtual folders (saved searches) to automatically process all subfolders of their selected target folders.
The search targets are updated automatically whenever a new folder is added, or a virtual folder is updated.
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.
Inbox Cleaner of expired Emails Requires Restart
Moves expired Emails out of your Inbox!
Adds personal filters to quickfilter toolbar
Gravatars Requires Restart
Show a column with the Gravatar-picture and sender-name in email folders.
Automatically marks all messages in the [Gmail] folder and all subfolders as read. If your GMail uses localized (translated) Gmail folder names, you set them in Thunderbird preferences: extensions.mark_gmail_read.folder_names.(all_mail|important|star
Delete Only Empty Folder Requires Restart
Disallows to delete not-empty mail folders.
YNote Requires Restart
Make some text notable on the each folder in folder's property dialog box.
Mailing list filter Requires Restart
Mail filter search term using mailing lists (and not whole addressbooks).