Add-ons

Provider for Google Calendar by Philipp Kewisch

Allows bidirectional access to Google Calendar

gContactSync by Josh Geenen

Synchronizes contacts & groups between Thunderbird and Google Contacts.

DKIM Verifier by Philippe Lieser

Verifies the DKIM-Signature of an e-mail.

Quicktext by John Bieling

Quicktext is an extension for Thunderbird that lets you create templates that can be easily inserted into your own emails.

Collector's Note Make text templates that can be inserted into emails when composing.

quickFilters by Realraven (Axel Grude)

Quickly generate mail filters on the fly, by dragging and dropping mails and analyzing their attributes. Create a filter in less than 10 seconds, it's as easy as: drag, click, click.

By popular demand, supports SORTING filters alphabetically.

XNote++ by opto

Persistent sticky notes associated to emails. You can fulltext search with constraints/email them/print/bookmark/copy to clipboard.

If you have a large screen, you can even display the notes outside of TB's main window, so it won't hide anything.

FiltaQuilla by R Kent James, Realraven (Axel Grude)

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.

Restart by Schuzak

"Restart" menu and button, with configurable shortcut key.

Header Tools Lite by opto, Paolo "Kaosmos"

Allows to modify the header and the source of messages

Correct Identity by ldreier, Dennis Verspuij

Ever sent mail from the wrong email address because you forgot to select the correct identity?

Filter Button by ChristophK

Allows to add a button to the message header view toolbar that shows all filters that match the selected message, including manual and disabled filters. A click on the button allows to select a filter to run.

MailHops by Andrew Van Tassel

MailHops maps the route an email took to get to you. Displaying the senders location, weather, user-agent and authentication used.

Collector's Note MailHops helps you identify spam by showing you the true origins of the email.

JunQuilla by R Kent James, Christopher Leidigh

1) adds column with percent likelihood that a message is spam, 2) extends junk status column to show why a message was classified as junk/good, 3) adds an Uncertain folder for messages needing user decision.

Toggle Headers by mattsch

Allows to switch between the normal header view and viewing all headers when viewing a message by using a keyboard shortcut (Ctrl+H).