Thunderbird Community Forum

In TB prior to v.155, folder message counts were not shown at all if the respective folders were empty. That is, instead of showing "0", TB did not show anything.

Now, after updating to TB v.155.0.1, I see dashes (horizontal lines) in the folder tree to the right of each empty folder.

Is it possible to revert back to the original behaviour and get rid of those unsightly dashes? They only add visual clutter (my opinion, obviously) while not providing any extra information.

Thanks.

I've been using Thunderbird version 155.0 with only a few issues (reported in other posts).

To investigate one of the issues I've had to create a new profile for testing. I've managed to set everything up except for my default font for outgoing emails. If I send an email with say, four lines of text, I can format each line to be a different font and the received email reflects the different fonts for each line.

But Thunderbird isn't remembering the last selected font. So if I send a second email (without re-selecting any font) the recipient receives it in some naff mono-spaced font. I guess there's somewhere where I can set up the default font for my outgoing emails but I haven't managed to find it yet. Can anyone help?

I’m trying to understand how Thunderbird handles links to online media when an email contains a link to a photo or video rather than a normal attachment.

For example, if an email contains a link to public Instagram media, I may open it in the browser and use a browser-based option such as Indown.mobi to work with the media. Is there any Thunderbird setting that affects how these external media links are opened or handled?

I’m mainly interested in understanding whether Thunderbird treats these differently from normal attachments and whether there is a recommended workflow for managing them.

I have no idea what happened to my Thunderbird. I think it might have been an update, because all of my folders are not where they were, everything in the folders are sorted by groups like today, or older. I noticed a bunch of my emails are now in folders marked as a Userfolder#. The emails it contains are those that normally should be in a properly named folder, only those named folders are grayed out. Another issue is that when i try to open an email, it opens it as if I want to reply to it. If I just want to read the email, I have to right click on the email and select open to read it. I have 2 spam folders, no idea why, nothing saves to my draft folder I found out today, I just dont know what happened! I dont think I did anything but I dont know now, as Im beginning to doubt myself. It's been this way for a few days.

I use Message Filters in Thunderbird extensively. Some of the grouped filters have many entries. Is there a quick way to find individual filter entries while using Thunderbird to, for example, modify or delete them? The only way I know of at the moment is to edit the the msgFilterRules.dat file as a text file.

Hi, I found an entry in the "thunderbirdmail.de" forum from 2005, where they discuss the option of using userChrome.css for changing the number of lines in the title of an calender appointment.

My problem is, that if the text of the title is really long, thunderbird will not enlarge the title window (more lines), so I can see the whole text (as in Outlook - from where I just changed to Thunderbird a few weeks ago).

The entry into the userCrome.css (as suggested in the forum)

.calendar-color-box .event-name-label {

  white-space:  break-spaces !important;

}

is not working (even I changed the "toolkit.legacyUserProfileCustomizations.stylesheets" to "true").

Can you help me with that issue?

Best reagrds

Gerd Attached screenshots

When links appear in a message, a mouseover used to display its URL at the bottom of the window. It has stopped doing so. It was a real help in catching scams. How do I get it back? Help / About shows "Thunderbird is up to date."

Years ago when I was using Thunderbird there was "fix" for the Advance to next message pop-up, which appears when you press N or P to move to the next/previous message, and that message is on another account. If I remember correctly I think the fix was going into the "debug list" where you could change individual settings if you knew the name of the setting, and set it to off.

Anyway I couldn't find that list at all in the current version (probably a good thing). Is there a setting somewhere or fix where I can turn off this popup?

I have over 200 email accounts in Thunderbird, and I am getting constant pop-up error messages that say: "Не удалось открыть индексный файл для 'Входящие на [email]'. Возможно, произошла ошибка на диске или полный путь превышает допустимую длину."

I don't need help fixing the emails themselves, but I need to permanently disable these pop-up alert windows because I will soon have over 2000 accounts and I don't want 2000 errors popping up.

I am using the latest version of Thunderbird. I have tried looking for "about:config" or the "Navigation Toolbar" to change the settings to "false", but my interface is heavily customized and I cannot find the menu or the address bar. I need a step-by-step guide on how to disable these error alerts, preferably using the Windows Registry or a configuration file if the menu is hidden.

Hey everyone

I need to remove the line that is added when you reply to emails. It adds added steps when cutting and pasting when I quoting emails when replying.

I have multiple profiles with multiple emails in each profile.

I found a thread here dated 2016 that instructed to add this to the css file.

I didn't have en excisting css file I could fine so I created a folder. >chrome > and put a userContent.css file within that.

This is code.

blockquote[type=cite] {

  padding-bottom: 0 !important;
  padding-top: 0 !important;
  padding-left: 0 !important;
  border-left: none !important;
  border-right: none !important;

}

I have Thunderbird 153.2.0esr which runs 2 Email filter (on Inbox and on Outbox)

These filters worked for years.

Suddenly, about at the end of July 2026, the stopped working.

I suspect that one of the latest release of Thunderbird make them stop working.

Is it possible? Any suggest?

Also the filter log registry is empty.

An example of an added space would be:

director-concertband@oceanside- music.ca

Note that after the second dash in my address above, in the saved HTML Sig Card, the space is added. When I remove the space and re-save the Sig card, the space still returns.

Also note that this happens ONLY in the signature card. The addressing in the email itself is correct. Any help you can offer would be appreciated.

On September 5, Thunderbird updated to 155.0 (20260828141248) (on Windows 11 10.0.26200). I use IMAP.

Since then, when I try to delete a message, I get an error: The current operation on ‘Inbox’ did not succeed. The mail server for account <email address> responded [TRYCREATE] Mailbox doesn’t exist: INBOX/Trash (0.001 + 0.000 secs)

But in Settings, "When I delete a message: Move it to this folder: Trash" is set. Not Inbox/Trash or INBOX.Trash, which also exist, but Trash at the same level as Inbox. I logged into webmail for this account, and there's definitely a folder for Trash. All deleted messages prior to the update are still there. If I delete a message in web mail, it is moved to the Trash folder.

The same is true of the Sent folder. In Settings, "When sending messages, automatically: Place a copy in: "Sent" Folder on: <account name>."

It looks to me like Thunderbird is doing something different from what the Settings say, and definitely something different than what it did before the update.

Suggestions?

With my new monitor, I've run into a problem with the space available for the actual message. On the attached image, I'd like to completely delete the stuff circled in red. I don't use it and it takes up a lot of space. I've resized the first two columns as much as I can, but I still can't see any of my full messages unless I open them in a new window or tab, which is inconvenient.

Thanks for any help you can give me!

I'm aware (e.g. https://support.mozilla.org/questions/1277401) of how to toggle whether the message window stays open (opening the next message) when an email is moved or deleted. But I would dearly love for it to happen only sometimes.

Specifically, when a new message comes in, I want to read it, usually move or delete it, then read the next new message, if there is one. But if the next message is an old one, I don't want to keep having it shown to me. I keep my inbox fairly tidy, but I'm getting sick of seeing that message from a year ago that doesn't have a better place to be.

So, after moving or deleting a message, if there is an adjacent unread message, keep the window open. Otherwise, close it.

If there's an unread message somewhere else in the folder, don't jump to that one. Trust that I've left it unread for a good reason, and don't want to now constantly get shown it, and also have to remember to mark is as unread again.

If it's easier to look for other unread emails based on dates, a few days (enough to span a long weekend, for example) would probably be enough, a week at the most. Or make that number user-configurable.

I used to be able to set message filters to play a sound of my choosing after a message was filtered into a folder (a chime so i know when mail from a client arrives). For a while it was not an option, so I used various extensions that eventually were no longer supported (ToneQuilla, Mailbox Alert, FiltaQuilla, Soundmail). I suspect that the last one may have corrupted my Thunderbird and caused my recent issues, so I removed it (and now I have no extensions installed). Sound Mail is the only extension I can find that plays a sound for filtered mail only.

Meanwhile, the "Play Sound" option has appeared again in v155.0.1, but with no choice of sound file, and nothing plays. It's not a sound issue; other sounds play in other programs, and the normal new mail sound plays when I enable it (but I don't want sound notifications for all mail, just client mail).

Any solutions?

On early version of Thunderbird on Windows 7 I see the mesage window below the header window. I would like to see the same on the later version on Windows 10 and 11. So far I've been unable to find a control to do that.