Allday Tasks

Thunderbird lacks the ability to create and manage allday tasks. This add-on adds these capabilities.

Send Later

True "Send Later" functionality to schedule the time for sending an email.

iCanban - Kanban with ICAL

All Events

Show past, future or all events

Provider for Exchange ActiveSync

Add sync support for Exchange ActiveSync (EAS v2.5 & v14.0) accounts to TbSync

CalendarSearchExport

Exports the results of a search in calendars

ElsHelp

Extension for ElSchool diary

TbSync

TbSync is a central user interface to manage cloud accounts and synchronize their contact, task and calendar information with Thunderbird.

EDS Calendar Integration

Integrates calendars events with Gnome clock applet

mailmindr

Follow up for Thunderbird E-Mails.

Web: https://mailmindr.net/
Twitter: @mailmindr

Date Time Formatter

Shows relative date-time in the column.
Note: you need to click "Select columns to display" and then -> "Relative Date/Time"

More Snooze

This add allow to customize the snooze delay when snooze popup appears (lightning required).

Mahoor-Iranian-Date

This add-on adds a new column called "تاریخ" ("Date (Persian)" since V1.1.3) in message list containing Iranian Date.

It is reimplementation of Iranian date for Thunderbird 78+ and 115+. The source is based on Full address column by Łukasz Kosson.

Lightning Invitation Notifier | LIN

This extension is an extension to Mozilla Lightning for Thunderbird.
It shows a toast message and opens the invitations window when an invitation arrives.

Provider for CalDAV & CardDAV

This extension is no longer needed. Thunderbird has native CalDAV and CardDAV support.

Lightning Calendar Tabs

Displays tabs which allows quick navigation between time periods in Lightning calendar. All views of calendar are supported. Color of tab texts can be adjusted.

Birthday Calendar

Adds calendars containing the birthdays from your address books.

Multimonth view

Multimonth View allows users to display multiple months in a single calendar view,

Macro Template

Macro Template is to replace mail templates with macros for date formatting.

Proton Calendar Toolbar Button

Adds a Proton Calendar button to the toolbar. The button simply opens a new tab with the https://calendar.proton.me webpage.