Mozilla has just unveiled Thunderbird v134, a much-loved and widely adopted desktop email client, as a continuation of the stable 128 “Nebula” release, bringing some exciting new features alongside critical bug fixes.
But first, let’s make this perfectly clear—this version is not intended for general use; instead, it offers a glimpse into what the next stable release might hold. Those curious to try it out can do so on Windows 10 or later, macOS 10.15 or later, and Linux with GTK+ 3.14 or higher.
With that in mind, let’s move on to what’s new. The release’s highlight is the new real-time desktop notification system. With this new feature, Thunderbird can deliver immediate alerts on your desktop whenever new mail arrives, ensuring that important messages never go unnoticed.
Moreover, the development team has tackled an extensive list of bugs. For instance, in-app notification messages now display correctly in dark mode, and alignment issues with the notification close button across multiple platforms have been resolved.
You’ll also find that POP3 users may see fewer crashes, as Thunderbird no longer encounters startup failures in certain configurations.
Additionally, Thunderbird 134 fixes pesky quirks such as the “Reply” button defaulting to “Reply-All,” the “mailto:” links failing to use the correct compose format, and the macOS shortcut CMD+1 not properly restoring minimized windows.
Performance improvements include smoother message list updates, as well as reduced delays in large virtual folders.
Finally, for those who rely on tasks and calendars, Thunderbird now addresses issues that previously caused the Today pane agenda to scroll mysteriously, along with faster startup for those using CalDAV calendars without offline support.
Security fixes and overall visual refinements round out this noteworthy update.
Once again, remember that this version is purely for testing purposes. For more information on all novelties, see the announcement. Downloads are available here by selecting “Thunderbird Release” from the “Release Channel” dropdown menu.
