Thunderbird Community Forum

Since the last update , Tbird is either a default window occupying ~1/3 of the screen , or full screen. The horizontal divider between message list and messages works. resetting/changing font size didnt solve it neither did

changing toolkit.legacyUserProfileCustomizations.stylesheets from false to true

or creating a new profile

OS linux mint 22.3 Tbird 140.10.0esr

One of my local folders of email disappeared: it is no longer displayed under Local Folders. A few days ago while using my mouse to move a message into one of the local folders, something happened, a peculiar message briefly displayed. At the time I did <Ctrl>-Z to undo whatever happened, but I didn't see any changes. That must be when the folder disappeared, but I'm not sure.

My other folders are still in place. I can't find the missing folder inside any of the other folders (junk, deleted, archive, etc.). Yet when I search for email in one of the missing folders, the messages are found. When I go into Troubleshooting Information, there is no Profile Directory listed, and when I click on the Open Directory button, nothing happens. (I've gone through the process of transferring Thunderbird accounts to new computers in the past.) I'm using Pop!_OS 22.04 Linux and Thunderbird 140.10.0esr. I backup my laptop using Back In Time. Any idea how can I fix this?

I'm concerned I've got my Junk set up so that TB is not actually learning what is spam, plus spam is not easy to delete.

First question. What is putting [SPAM] in headers before emails arrive? Is it SpamAssassin? I use my own website/email address and my host uses Spam Assassin. My host in addition has their own native Bayesian spam, but that would use *****SPAM***** headers and I never get these.

The problem is this. Most junk arrives marked [SPAM] but doesn't go in the Junk folder, which is the only folder with one-click Empty Junk. So I have filters set up to direct headers with [SPAM] in into the Junk folder.

(i) the [SPAM] arrives in the Junk folder not marked as Junk even though the filters are carefully set up to "Set Junk status to: Junk"

(ii) it doesn't seem possible to bulk mark the contents of the Junk folder as Junk. If I click the flame icon in the header row once, then all the flame icons are switched to not-Junk as expected. But if I click it again then only some, not all, are changed back to Junk. IE completely different from normal all-off/all-on conventions.

(ii) some [SPAM] ends up in the Spam folder despite the filters. This looks like pure filter failure.

The goal is the get all the [SPAM] messages in the Junk folder along with the Junk the TB itself puts there, so (a) I can delete them with a single click plus (b) all marked as Junk so the TB is learning from the [SPAM] emails.

How can I do that please? What am I doing wrong?

Many thanks.

I’d like to request a feature for Mozilla Thunderbird on Ubuntu/Linux:

A native system tray (AppIndicator) integration with the ability to: • Run in the background without keeping a window open • Minimize to tray instead of the taskbar/dock • Option to start minimized to tray on system startup • Show unread mail count directly in the tray icon

Right now, users rely on third-party tools like Birdtray, which work but feel like a workaround rather than a seamless experience. A built-in solution would improve usability significantly especially for those who prefer a clean desktop while keeping Thunderbird always running in the background. I think this feature would bring Thunderbird closer to the behavior users expect from modern messaging/email clients on Linux desktops. Would love to see this considered in future updates!

I am running Thunderbird 140.9.1esr on openSUSE Tumbleweed.

For a long time now, Thunderbird often runs at high CPU (80-100% of one core), for several minutes at a time (5-10 minutes). This seems to happen many times every day, with no apparent cause from my end. (I just got back from Lunch, and the fan on my laptop was going crazy because of the high CPU.)

What can we do to identify and fix this issue?

Hello!

I have installed Thunderbird 150.0 on an Ubuntu 24.04 desktop using a downloaded TAR installation method. I have done this, as I use OWL for Microsoft Exchange accounts. OWL works better with the current version of Thunderbird.

I have created a desktop launcher (thunderbird-150.desktop), which works fine, except that the software icon is the generic Gnome gear. I have read that specifying the WMClass correctly in the launcher file (in /usr/share/applications) is the solution, but this does not seem to work. It is current set as WMClass=thunderbird. I have also noticed that the /opt/thunderbird/icons folder does not contain the Thunderbird icon.

Can anyone help me to fix this annoying issue?

Many thanks!

Hello!

I am using Thunderbird 140.9.1esr (64-bit) on a Ubuntu 24.04 system. Every time I restart Thunderbird, it reverts to a little used Gmail account as the default account. I have several accounts, but my main email account is a MS365 account. I reset the setting, but every time it is restarted, the default goes back to Gmail. I have tried everything that I've found online, but cannot correct this behaviour.

Do you have any suggestions or assistance?

Many thanks!

Hello, I use Thunderbird 140.10.0esr, installed as Flathub flatpak on Fedora Linux Kinoite. I just found out I have a folder in /home/<user>/.var/app/org.mozilla.Thunderbird/.thunderbird/1tniiwpw.default-release-1/storage/default/ called https+++www.googletagmanager.com. I wonder why I have this and what it does in the Thunderbird settings. It has something to do with Google's LLC, but I don't want to be part of that. I removed the folder completely and hope it won't come back, but I wonder. Who can tell me something more about this folder? Thanks.

bold texti have a thunderbird profile on exterior drive I have installed linux mint on my PC but cannot locate the profile to use my old TB profile -either by replacing it or renaming the old profile for the linux one

The website https://www.thunderbird.net/en-US/thunderbird/all/ provides portable download for Linux, but I seem to understand there's no such a version for Linux ARM (aarch64).

Is that planned in the future?

thanks in advance

I have Version 140.8.0esr | Released February 24, 2026, for Linux Mint (up to date)

I have a CardDAV address book on a Nextcloud instance that i want to sync to Thunderbird.

When i open Address Book and the clikc on " Create a new address book" the Account Hub modal window opens. None of the 4 options (including Add Remote Address Book" do anything, i.e. I can click as much as I like but nothing happens.

I recieve several emails a day from a submission form on my website that contain what looks like Russian words. I would like to create a message filter to move these messages directy to the trash based on one or two characters that do not appear in the english language. I thought I had done it, but the filters don't appear to work.

Hello! No real issues or bugs to report, but I had some curiosities about independent audit documents. I appreciate the dedication to privacy and transparency, as I am sure many do; I've noticed that there are readily available audit documents for the Thunderbird Send and K-9 which is cool - are there any such audit documents for Thunderbird Desktop for Linux, or do the aforementioned documents sort of cover the same thing? If you could help me understand this (or perhaps point me to information or docs I missed), that would be appreciated!

Thanks for your time, --Mark

I'm a bit lost with the instructions http://mzl.la/1BsOG2o My thunderbird looks different I don't see a "Trust junk mail headers set by" option. What would be the proper way?

I deleted an old email address for a friend, but every time I email her, the auto-complete feature includes both the current email address and the one for her old job. I've deleted that one, and it doesn't seem to show up in the Address Book anywhere, so why does it keep coming up in the auto-complete?

It's annoying to me and to the place of employment to have the emails go to the wrong address when I'm not watching very carefully.

How can I make sure this doesn't happen again?

I am on Ubuntu 22.04.5 using Thunderbird 140.7.1esr (64-bit). After the latest update (from 128.12.0+build1-0ubuntu0.22.04.1) the notifications for mail has changed. Instead of just getting a notice, the notice now allows me to mark as read right within the notification (which is cool), but also now I am getting notifications when Junk mail comes in. Not a notification that it's junk, just that it is a new email.

I do *not* want these to automatically get marked as Read when they come in, as I do want to manually review them in case it's a mistake, and leaving them as unread in my Junk folder makes sense to me in order to make that easier. However, I do not want these notifications on each and every mail. If it's junk it should just silently classify it as such, like it used to. However, I cannot find a setting for this. is there a way to revert to the old behavior without rolling back to an earlier version of Thunderbird? Thanks!