Announcements

Welcome to Thunderbird 140 “Eclipse”

July 7, 2025 Monica Ayhens-Madon 0 responses

The wait is over! Thunderbird 140 “Eclipse” has reached totality. From all of us at the Thunderbird project, from MZLA staff and the Thunderbird Council to our global community of contributors, we’re excited to announce the latest Extended Support Release has arrived.

Eclipse not only builds on Thunderbird 128 “Nebula,” but also the recent features and improvements from the Monthly Release channel. This latest release transforms your email experience with adaptive dark messaging and improved visual controls. Enhanced features keep everyday email tasks light and effortless, while the streamlined new Account Hub ensures adding new accounts is a snap.

Dark Message Mode

Thunderbird’s Dark Mode now automatically adapts your messages when enabled, to ensure your Dark Mode experience stays totally dark. Need to bring your messages back into the light in case of visual problems? Adjust your message view as needed with a quick optional toggle.

Appearance Settings

Make Thunderbird yours across all your folders and accounts with a single click in the Settings (panel). Change your message list layout between Cards and Table view, adjust your Cards View, and set your default sorting order and threading options with ease.

Native OS Notifications

Leverage the speed and ease of your Operating System’s built-in notifications, whether you’re on Windows, Linux, or Mac. Quickly delete, archive, or use customizable actions directly from your notifications and get more done with your day.

Account Hub

Adding a new account to Thunderbird is now easier than ever. Connect all of your emails, address books and calendars in a few easy steps.

Manual Folder Sorting

Don’t like the order for your custom folders? Just click and drag to arrange them exactly how you want.

More Refinements & Updates

Experimental Exchange Support Natively set up a Microsoft Exchange account in Thunderbird by enabling a preference.

Export for Mobile Generate a QR code to quickly transfer your account settings and credentials to your Thunderbird for Android app.

Horizontal Scroll for Table View Lots of tabular data? Let the message list scroll horizontally, like a spreadsheet or file manager.

Bug Fixes and Improvements

Thousands of bug fixes and performance improvements to bring you the smooth, reliable Thunderbird experience you expect.

Looking Forward

Whether you’re waiting for the next Thunderbird ESR or total solar eclipse, we understand that sometimes you want new features, or that cosmic awe, sooner. While we can’t change the universe, you can now get the latest Thunderbird features as they land, instead of once a year. Switch to Thunderbird Release and enjoy monthly updates with the same dependable stability.

Thunderbird 140 Availability For Windows, Linux, and MacOS

Even with QA and beta testing, any major software release may have issues exposed after significant public testing. That’s why we are slowly enabling automatic updates until we’re confident no such issues exist. We do have a known issue where users sending mail through 32bit MAPI will be prompted for a password, unless they use the compose window.

We have enabled manual upgrade to 140 via Help > About, and you can upgrade now or wait to receive automatic updates. Thunderbird version 140.0 is also offered as direct download from thunderbird.net. Be sure to select ‘Thunderbird Extended Support Release’ in the ‘Release Channel’ drop-down menu.

For Linux users running Thunderbird from the snap or flatpak, 140 will be available within the next few weeks. Likewise, Thunderbird 140 will also arrive on the Windows store by mid-July.