PrettyBlockquote

The add-on ensures that the quoted text in your reply is clearly highlighted with a vertical blue line, even when viewed by recipients using different email clients like Gmail or macOS, by using inline CSS on the blockquote HTML tag.

addy.io / AnonAddy for Thunderbird

Adds a button to the message composition window which updates recipient addresses to route the outbound message through addy.io or a self-hosted AnonAddy server, so your real, private email address isn't exposed to recipients.

eMail Address Finder

This finds all email addresses in Body, From, & CC fields.

It will then put them all into a single menu.

You can click on the menu & copy the address.

For those wrangling email addresses all day, it's a massive time saver.

TriliumClipper

A Thunderbird extension to clip messages and send them to the TriliumNext note taking application.

Spellchecker Ladin (Val Badia)

Spell-checking dictionary for Ladin (Val Badia).

CrossBorderScam-Canceler

This add-on (CrossBorderScam-Canceler) filters fraudulent emails by focusing on the location of the received email and analyzing the header information of the opponent's email and the links in the email body.(view in English, Japanese or German)

OpenDetachedAttachments

Allows opening of detached attachments if they have been moved

Email Assistant

This Extension provides a framework for AI-powered email analysis. It processes incoming emails, sends them to a language model of your choice, and applies tags. This allows for sophisticated email classification and sorting.

Norsk nynorsk (nn-NO) Language Pack

Norsk nynorsk (nn-NO) Language Pack

Punjabi (pa-IN) Language Pack

Punjabi (pa-IN) Language Pack

userChromeJS

Load the contents of chrome/userChrome.js from the user's profile directory every time a window is opened. Also add a toolbar button which reloads userChrome.js in the current window.

Mailing list filter

Mail filter search term using mailing lists (and not whole addressbooks).

Slovenská kontrola preklepov (bez diakritiky)

Slovník pre kontrolu preklepov bez diakritiky pre aplikácie Mozilla.

Phoenity Icons

Phoenity icons for Thunderbird

Dolibarr connector

Extension Thunderbird pour intégrer Dolibarr

iCanban - Kanban with ICAL

Gàidhlig (gd) Language Pack

Gàidhlig (gd) Language Pack

Use BCC Instead C Requires Restart

This addon prevents you accidentally sending an email to a large number of recipients without hiding their addresses from each other by using BCC. It is for TBv68.

IT WILL NOT BE UPDATED FOR TBv78.
Try my addon 'Limit non-BCC recipients'

ansitel Click-to-Dial

This plugin will call a selected number by clicking the right mouse button.

BorderColors D

Shows a colorful border around the "New Message" window, so you can tell different identities apart.

Builds on the original BorderColors and the "GT" version, adding different border styles.