Add-ons

ImportExportTools by Paolo "Kaosmos"

Adds some tools to import and export folders and messages

Collector's Note Import Export Tools

Provider for Google Calendar by Philipp Kewisch

Allows bidirectional access to Google Calendar

Collector's Note Provide bidirectional connection to Google Calendar

Enigmail by Patrick Brunschwig

Helper tool to migrate your keys and important settings from Enigmail to Thunderbird 78.

Collector's Note Advanced Privasy and Encryption

Spanish (Spain) Dictionary by tnarik, RickieES

Spanish/Spain Dictionary

Collector's Note Spanish Spellchecker

Saved Password Editor by Daniel Dawson

Adds the ability to create and edit entries in the password manager.

Password Exporter by Justin Scott (fligtar), Jorge Villalobos

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.

Collector's Note Option to export passwords

Remove Duplicate Messages by Eyal Rozenberg

Search and remove messages which are the same as other messages in your mail folders (referred to as duplicates or dupes).

Collector's Note Better duplicate message remover

MinimizeToTray revived by Nils Maier

Minimizes windows into the system tray.

Collector's Note As the name speak for it ;)

Signature Switch by Achim Seufert

Switch the signature on/off or choose a new one from your predefined set.

Collector's Note Easiest way to swith your signature

CompactHeader by jmozmoz

Add symbol in header plane to switch between compact and expanded view. Work only for Thunderbird 68.0 and older. Currently, there are no plans to update this for newer versions.

Collector's Note Shows additional lines in header pane

QuickFolders (Tabbed Folders) by Realraven (Axel Grude), Alexander Malfait

The "Swiss army knife" of folders. Turn your favorites into tabs - open folders and subfolders, move mails without scrolling around or searching. powerful + easy.

See new mail at a glance after automatic filtering - supports quickFilters addon!

Collector's Note Pretty nice extension for easiest access folders via tabs

Stationery by Arivald

Extension to mimic Outlook Express Stationery.
Allow you to use HTML files as templates for mail. Also allow custom template in replies or forwarded mail!

Collector's Note The way taht make Templates easy as in Outlook Express

Addressbooks Synchronizer by Günter Gersdorf

Synchronizes selected addressbooks with other instances of thunderbird
using local files, webdav servers or imap servers

Collector's Note Syncronization for Addressbook

Calendar Tweaks by DW-dev

Allows several tweaks to the Thunderbird/Lightning calendar user interface including new selection styles and repeating event icons. Mimics the colors and styles found in MS Outlook.

Collector's Note Few tweaks that make the Mozilla Calendar (Lighting) better and more good looking

Google Contacts by H.Ogi

Access to Google contacts and synchronize them with Thunderbird address books.

Collector's Note Provide option to obtain Google Contacts