Most Popular Extensions
Adds tools to import/export messages and folders (NextGen)
NEW 102 & 91 Compatible version . Linux & OSX PDF Export Support.
See Changes below
Provider for Google Calendar
Allows bidirectional access to Google Calendar
Manually sort folders
This extension allows you to manually sort (order) your folders in the folder pane of Thunderbird or automatically sort them, but in a better way. This extension also allows you to re-order accounts in the folder pane.
LookOut (fix version)
LookOut is a plugin which allows Thunderbird to interface with Microsoft's mail tools by decoding metadata and attachments encapsulated/embedded in a TNEF encoded attachment (aka winmail.dat).
Quicktext is an extension for Thunderbird that lets you create templates that can be easily inserted into your own emails.
True "Send Later" functionality to schedule the time for sending an email.
Remove Duplicate Messages
Search and remove messages which are the same as other messages in your mail folders (referred to as duplicates or dupes).
TbSync is a central user interface to manage cloud accounts and synchronize their contact, task and calendar information with Thunderbird.
A new Thunderbird address book based on the CardDAV and vCard standards.
Create and Save or Send Multiple Individual and Personalized Messages from a Draft
Switch the signature on/off or choose a new one from your predefined set.
Provider for CalDAV & CardDAV
This extension adds support for CalDAV & CardDAV accounts to the Thunderbird Sync manager "TbSync". Including iCloud, ownCloud, Nextcloud, Radicale and many more.
FileLink Provider for Dropbox
Uploads your large attachments to your Dropbox instead of sending them by email. This uses Thunderbird's FileLink feature.
Owl for Exchange
Allows you to use your Exchange and Office365 email account with Thunderbird using Outlook Web Access (OWA).
FileLink provider for WebDAV Featured
Uploads your large attachments to your WebDAV account instead of sending them by email.
Grammar and Spell Checker — LanguageTool
Check your emails for spelling and grammar issues
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.
Minimize on Close
Causes Thunderbird's main window to minimize instead of closing. You can still close Thunderbird through the menu.
Provider for Exchange ActiveSync
Add sync support for Exchange ActiveSync (EAS v2.5 & v14.0) accounts to TbSync
FileLink provider for Send
Securely encrypt and upload large attachments to any Send service instance (formerly Firefox Send).
To create your own collections, you must have a Mozilla Add-ons account.