Thunderbird 142 comes loaded with changes that aim directly at productivity and security. The veteran open source email client, available for GNU/Linux, macOS, Android and Windows, chains an update that is not limited to polishing errors: it also incorporates useful functions that are noticed on a daily basis, such as the possibility of adding visible signatures to Attached PDFs and much finer control over folders.
Beyond the background improvements, there are tweaks to user experience that simplify small repetitive tasks, repairs that correct historical annoyances and a good package of security patches It's a good idea to install it as soon as possible. If you use Thunderbird intensively, this intermediate version based on the Firefox 142 code will be especially interesting for you because it combines new features, organization, and protection.
Visible PDF Signatures: Thunderbird's New Feature That Saves the Most Time
The star feature is the new support for adding visual signatures to the PDF documents you attach to your emails. This isn't just a cosmetic detail: it allows you to clearly mark a PDF with a visible label or signature, so the recipient knows at a glance that the document is coming verified and authorized For you. It's ideal for work processes, agreements, internal approvals, or any workflow where you previously needed to open another app or website to sign.
This change prevents you from depending on external services (some paid and others with security risks) and allows you to complete the process without leaving Thunderbird. In scenarios where you previously resorted to third-party applications or online sites of dubious reputation, now it is enough to manage the signature from the client itself, maintaining the traceability of the email and the attachment within the same environment.
It is important to distinguish between the Electronic signature which certifies the integrity of the content and the visible signature or graphic label that adds an explicit reference to the PDF. Thunderbird 142 gives you that missing visual layer and, in addition, continues to offer the flow of digitally signed of the message to reinforce authenticity. Both pieces add up: one facilitates immediate human recognition; the other provides cryptographic assurance.
If you want to activate the digital signature of the email, the flow in the app is very direct: from Configuration you display the left menu to choose the account mail that you will use, you enter Security and you access Digital Signature to select the certificates or corresponding document. Then, when writing, open Security and select "Digitally sign this email." This way, the message travels with the cryptographic seal and your PDF attached It may also include a visual signature that quickly identifies it.
Folders under control: copy, reorder, and return to default order
Those who work with many folders will appreciate several much-requested improvements. For one thing, You can now copy folders to the mail server or move them to local folders, something key to reorganizing archives, consolidating structures or replicating hierarchies between accounts without cumbersome manual strategies.
In addition, Thunderbird 142 adds a option to reorder the sorting of the folders in the panel. If you've been fine-tuning the order for years and have ever "broken" it with a bad maneuver, there's a new button “Reset folder order” which returns manual sorting to its default state. Small touches that, when combined, make navigating through dozens or hundreds of folders much more bearable.
The tweak isn't limited to mail: starting with this version, new newsgroups are added by default in alphabetical orderThis consistent behavior prevents surprises when you subscribe to or create groups in busy environments, and makes it faster to find what you're looking for without wasting time manually reordering.
Simpler menus: new links to copy and a necessary cleanup
Menu More Actions is updated with two very useful entries: “Copy link from message"And"Copy news links”. From now on, it's easier to share or save a reference to a specific message or news/group post, which simplifies workflows with colleagues or when you organize with external task managers.
As part of this cleanup, the classic option disappears from the context menu “Copy Message Location”The idea is to reduce redundancies, centralize link copying where it makes the most sense, and, at the same time, minimize confusion for those unfamiliar with the subtle differences between seemingly similar actions.
Thunderbird 142 introduces experience improvements: notifications, dark mode, and interface details
The sound notifications receive adjustments, and the system's "Do Not Disturb" mode will be respected to block audible alerts when appropriate. If you use Thunderbird while concentrating or sharing an environment with others, you'll appreciate that the client aligns with the global politics of the operating system.
A classic that is finally resolved: the dark mode now also applies to posts, not just the interface. This improves visual consistency, prevents glare from occasional bright backgrounds, and reduces eye strain during long sessions.
On Linux the behavior of the subtitle button, which was problematic in certain circumstances. While it may sound minor, these types of fixes make a difference on platforms where the detail of integration and window managers matters, and reinforce the feeling of multiplatform care.
Another great little detail: the icon of backspace The Quick Filter feature no longer unexpectedly clears the search field. This gives Quick Searches the predictability you'd expect from a filtering tool you use dozens of times a day.
Calendars, feeds, and contacts: a stronger ecosystem
In the calendar part, support is reinforced for the Fastmail calendarsThis is good news for those who use Thunderbird with this provider and have encountered inconsistencies when syncing and editing events. The more robust integration reduces errors and friction in calendar management.
For users of RSS feeds, fixes an annoying behavior where archived messages were no longer going to the correct folder and were ending up in the wrong locations. With the fix, archiving a feed is once again a reliable and predictable gesture, keeping the contents in the correct site.
The ability to display is also incorporated contact photos in WebP format obtained from servers CardDAVThis avoids unnecessary conversions and ensures that the address book looks exactly as you've configured it on your server, with modern, lightweight, and high-quality images.
And for those who still participate in newsgroupsPost submissions, which could fail under certain conditions, have been fixed. This improvement ensures the client responds well to these more "classic" but still relevant flows.
Thunderbird 142 Availability and Download
The version can now be downloaded from the Official Site of Thunderbird, where we also find the notes from this release. If you use Linux (Linux Mint will offer DEB version), macOS, Android or Windows, it's a good time to update and take advantage of both the new visual signatures in PDF such as folder control, menu cleanup, and security patches. For those who want to get into the technical details, there are always the release notes with the exhaustive list of changes and links to security notices.
Those who come from previous versions and want to update will find a Thunderbird with practical functions that weren't there, more serious folder management, a handful of noticeable fixes, and, above all, a foundation reinforced against recent vulnerabilities; the whole thing is more solid, more comfortable, and ready to fit seamlessly into any email routine.
