Beyond the Firefox browser to see more changes under its new CEO, the Thunderbird mail client is also expected to see some big changes in the new year.

Thunderbid today published their 2025 year in review while also offering a look ahead to 2026.

This year brought Thunderbird 140 as their newest Extended Support Release (ESR), native Microsoft Exchange email support in Thunderbird 145, continued work on their mobile story, and also the introduction of Thundermail and Thunderbird Pro.

Especially as demand for video grew, the web needed a next-generation codec to make high-quality streaming faster and more reliable. H.265 promised efficiency gains, but there was no guarantee of another OpenH.264-style arrangement. The risk was another fragmented ecosystem where browsers like Firefox couldn’t play large portions of the web’s video.

To solve this, Mozilla joined other technical leaders to form the Alliance for Open Media (AOM) in 2015 and started ambitious work on a next-generation codec built from Google’s VP9, Mozilla’s Daala, and Cisco’s Thor.

Mozilla has released Thunderbird version 146 of its widely adopted free and open-source desktop email client, now available for download.

On the new features side, the update introduces UI-based configuration of a preferred OpenPGP keyserver, giving users clearer control over where their public keys are fetched and published. Alongside this, Thunderbird migrates all existing logins to modern AES-based cryptography, improving security without requiring user action.

Last year, the Firefox team set out to test something fans requested: choosing a custom app icon. The experiment was simple. Offer a small set of options and see how people use them.

Thunderbird’s plans to expand beyond the desktop client took another step forward this month as the project published its latest progress report on Thunderbird Pro – the new Mozilla initiative to offer an open-source alternative to Gmail and Office 365, for which we informed you about at the beginning of April. Here’s where things stand so far.

Testing of Thundermail, the project’s email hosting service, has reached production level. Internal users have begun onboarding, allowing the team to validate account setup, support workflows, and delivery reliability. The refreshed Thundermail dashboard is also in place, giving users controls for custom domains, aliases, and account settings.

We recently shared how we are approaching AI in Firefox — with user choice and openness as our guiding principles. That’s because we believe AI should be built like the internet — open, accessible, and driven by choice — so that users and the developers helping to build it can use it as they wish, help shape it and truly benefit from it.

Mozilla has released Thunderbird version 145 of its widely adopted free and open-source desktop email client, now available for download.

One of the most notable additions is that the app now supports Exchange Web Services natively. This long-awaited feature simplifies the connection to corporate email systems, eliminating the need for third-party extensions. The update also allows manual configuration of EWS accounts directly within the Account Hub.

According to marsf, the long-time locale leader of the Japanese SUMO team, the decision to disband was triggered by the recent introduction of an automated translation system known as Sumobot. Deployed on October 22, the bot began editing and approving Japanese Knowledge Base articles without community oversight.

In a message posted to the SUMO discussion forum, marsf explained that Sumobot’s behavior was unacceptable for several reasons:

• It disregarded Japanese translation guidelines, resulting in literal and sometimes inaccurate text.
• It overrode existing localizations, effectively erasing community-approved work.
• It automatically approved machine-translated content for all archived articles within 72 hours, removing the review window for human contributors.
• It operated without consultation, control, or communication with the Japanese community.

Seems kind of dead.

If I save a page to a local HTML file, I do not see where the URL of the page itself is saved. There is no comment or anything at the top that contains the URL. So I have to either add a comment manually myself or make a note of it somewhere, or bookmark it.

Is there a smarter way of working? Can the URL be derived or fished out of the saved file, or is there any feature that saves the URL as well?