The new version Thunderbird 146 It is now available Available for download, this update focuses primarily on strengthening security, improving stability, and refining minor details for daily use. It's not a feature revolution, but it is an important step for those who use the email client as their main tool at work or home, as was the case previously. Thunderbird 145.
The program, developed by MZLA Technologies (Mozilla subsidiary)Thunderbird maintains its focus as a free and open-source solution for email, calendar, RSS, Usenet, and chat, with versions for Windows, macOS, and Linux. With Thunderbird 146, the team continues to refine the experience following the recent integration of Exchange in previous versions. Thunderbird 144 and while it prepares paid services like Thunderbird Pro.
Thunderbird 146 introduces new OpenPGP management and more robust password encryption
The most visible change in Thunderbird 146 is in privacy: it is now possible Configure the trusted OpenPGP server directly from the interfacewithout having to access advanced options or edit configuration files. A new "OpenPGP Key Servers" section appears in the Privacy and Security panel, where you can choose predefined servers or add others manually.
This improvement makes life much easier for those who depend on it. end-to-end encryption To protect email, it centralizes the import and management of public keys in one place. Additionally, a bug that could set an incorrect expiration date when extending the validity of an OpenPGP key has been fixed, and an issue preventing the signing and encryption of messages using the option has been resolved. -compose when Thunderbird was not running.
In parallel, the program Automatically migrates saved logins to AES encryption The update includes a more modern approach. Passwords are moving away from older schemes like 3DES-CBC with 112-bit keys to AES-256-CBC with 256-bit keys, strengthening the protection of credentials for IMAP, POP3, and other services configured in the email client.
Update focused on stability and security
Although the list of new features is short, Thunderbird 146 includes a long series of bug fixes These improvements affect both internal functionality and the user interface. They address issues such as unexpected crashes when renaming or moving email folders, as well as errors in the server subscription logic that could cause the program to freeze.
A memory leak when opening new windows from the context menu of the folder panel. The client now correctly releases resources after creating these windows, which is especially relevant on computers that remain on for many hours with Thunderbird open.
In terms of security, version 146 fixes several vulnerabilitiesincluding some classified as high severity. Full technical details are available in the release notes and on the Mozilla security page, and are largely shared with the Extended Support Channel (ESR), which has been updated in parallel with version 140.6.
Improvements to Exchange Web Services and Account Hub
Following the arrival of native support for Microsoft Exchange using EWS In previous versions, Thunderbird 146 refines this integration. Offline usage indicators for EWS folders are now correctly saved and retained after restarting the application, eliminating the need to reconfigure which folders are synchronized when the user is offline.
The option "Select this folder for offline useThe EWS folder properties are now working correctly, and bugs that could cause unexpected crashes during manual Exchange account creation from the Account Hub have been fixed. Additionally, an issue where the EWS "offline folder" flag was lost upon reopening the program has been resolved.
El Account Hub It also receives general improvements: it now includes a default output configuration during advanced setup, no longer fails when manually creating EWS accounts, allows generating a local address book without having to assign a blank name, and displays more accurate success messages about where the account configuration data comes from.
Settings for the interface, folders, and message management in Thunderbird 146
In everyday life, many small changes add up; that's why Thunderbird 146 introduces various improvements to the interface and folder managementIt is now possible to compose a new message even when the folder panel is empty, avoiding somewhat confusing situations for users with minimal or newly created configurations.
Folders with identical names are They distinguish better in the menus The "Recent Destinations" and "Favorites" lists are now correctly displayed when moving messages, reducing errors when archiving emails in mailboxes with complex structures. Additionally, the email context menu now correctly displays the "Labels" submenu, which in previous versions might not have been populated properly.
Another practical new feature is that the button "Remove" from the unified toolbar It now behaves more consistently: it deletes messages, not just attachments. Additionally, when multiple IMAP folders are selected, the "Delete" option appears in the context menu as expected, allowing for more straightforward management of these mailboxes.
vCards, recent recipients, and other tweaks
Thunderbird 146 also improves contact and card file management. Importing vCards (.vcf) has been polished so that the file selection box only shows this type of document, and opening vCards from the file manager or from the command line is now more reliable.
In the menu «Recent DestinationsWhen moving messages, the client can sort the list by modification time, so the most recently used recipients appear logically and are easy to find. This small modification simplifies quickly archiving emails into frequently used folders.
In addition, problems with the accounts columnThe security exceptions dialog box, which in some cases did not display the correct mailbox name, has been improved and now provides clearer information when adding a certificate exception. This improvement contributes to clearer and more accessible certificate management.
Specific fixes for Windows, macOS, and Linux
The update brings specific changes for each operating system. On macOS, one of the most discussed issues was the Drag and drop fails with attachments From Thunderbird to the desktop or a Finder folder. With version 146, this feature is working normally again, which is especially useful for those who manage documents directly from the email client.
In Windows environments, Thunderbird correctly marks the Microsoft Office attachments with the MOTW tag (Mark of the Web) when opening them, which helps the operating system's security mechanisms to treat those files as coming from the Internet and apply the appropriate limitations.
What interests our readers most, in Linux, is that the new version continues to be distributed through the repositories of the main distributionsHowever, those who don't want to wait can download the official package now from the website. On all systems, the program better frees up memory after opening new windows from the folder panel, reducing resource consumption during long sessions.
Requirements, ESR channel and availability of Thunderbird 146
Thunderbird 146 maintains the minimum system requirements Previous versions: Windows 10 or later, macOS 10.15 (Catalina) or later, and a current GNU/Linux distribution with GTK+ 3.14 or higher. This makes the upgrade accessible to the vast majority of computers in use, both in home and office environments.
Like Firefox, Thunderbird offers a extended support channel (ESR) For organizations that prioritize stability over new features. This channel has been updated in parallel with version 140.6, incorporating most of the security fixes from Thunderbird 146, but without yet adopting all the features that have been added since the 140 branch.
Users can update from within the program itself, through the integrated update system, or download the installers from the Thunderbird official website both in 64-bit binary version and in source code, something that remains relevant for administrators and IT managers who manage deployments in European organizations.
Thunderbird today: classic client and foundation for future services
Beyond the technical specifications, Thunderbird 146 consolidates the customer as central piece of the email and productivity strategy of the project. Alongside the program itself, the team is working on Thunderbird Pro, a subscription service that promises email hosting, encrypted file sharing, and advanced calendar tools, designed primarily for professionals and small businesses.
While we await those new paid features, version 146 reinforces the value of the classic desktop client: software that continues betting on personalization through add-onsIt integrates OpenPGP encryption by default, offers calendar and task management, and maintains active development based on community contributions. For those who need a robust email client with Exchange support and an open-source technology foundation, this update may not be groundbreaking, but it does provide the necessary stability, security, and minor tweaks that are appreciated in daily use.
