Thunderbird Community Forum

May 25 2026. A few days ago, Thunderbird upgraded me to Release 151.0. I can no longer send or receive emails.

My wife has been upgraded to ESR 140.11.Oesr, and she has no problems.

I do not want to go through the tests of removing virus guard etc to try to make 151.0 work, so I would like to move to ESR 140.11, but cannot find online how to do that?

Please help.

Edit address book entry displays only DELETE and CANCEL at the bottom of the edited entry. The rightmost border may be obscured as the display does not allow for scroll.

Week starts on Sunday. Events scheduled for Monday through Thursday. Select event set for Thursday and Crtl+P. Print preview shows event scheduled for Monday, not Thursday's event.

This morning I noticed that all emails prior to May 1 were missing from folders that I created. I assumed (incorrectly) that they were in the sbd file that I backed up in April. So I moved that file into the proper destination location but nothing popped up. I then restored the old sbd file back and now I don't even see any the the folders that I created. Note: when I click on the sbd file I do see the folders but they don't appear under Local Folders I've googled and used AI....no luck

I find 'threading' useless and confusing. I want to turn it off for every message, everywhere. But the drop down menus with items about 'threading' seem locked. I cannot uncheck anything. Not just that the checks return when I re-open Thunderbird, but also the checks don't respond to keyboard input to disappear.

How can I get rid of this horrible attempt the software is making to think for me? It always gets things wrong.

Hello, I have a Thunderbird shortcut on my desktop.

When I try to move the icon to the taskbar, it doesn't appear.

I'm running Windows 10 on a new PC (ASUS GALAXY 5 PRO). Thanks in advance.

Does clearing up disk space from this option(see image) delete the emails from server as well? I have attached the image, if I were to delete the emails from this option will it delete the emails from the server as well? and additionally I couldn't find the manual triggering of "Compact Folders".

我最近遇到了无法发送邮件的问题，我尝试删除账户重新登录，但是遇到了一个问题：获取登录信息默认使用本地电脑的 443 端口，但是与 Steamcommunity 302 和 Laravel Herd 等涉及使用 https 端口的软件冲突，希望能够改为随机端口以解决该问题。

I recently ran into an issue where I tried to delete my account and re-login, but I had a problem: getting login information was used by port 443 of the local computer by default, but with Steamcommunity 302 and Laravel Herald and other software conflicts involving the use of https port, hoping to change to a random port to resolve the issue.

I regularly get the following message when attempting to send an email :- "Sending of the message failed. The message was not sent due to exceeding the allowed number of recipients. The server responded: Policy-SC01 You’ve reached your sending limit. Don’t worry, you can send again soon.." This message implies that I am attempting to send a message with multiple recipients, BUT it only happens when I am sending to only ONE recipient. Why is this, and how do I eliminate this very annoying restriction. I currently cannot send an email because this problem is preventing me from doing so. Thunderbird has been a useful email client for many years, but these frustrations are not helping me to remain with Firebird. Regards, PD

Under my email address, Jim@JimFrance which is not registered on this site, I had two folders to which I had moved important emails in order to save them. One of these folders I restarted since it was relatively new and I could still search and find the emails. The other one is months of work. It is not in my folder list. It was there yesterday. But when I fired up Thunderbird this morning, it has vanished. How do retrieve it?

I've used thunderbird for years. Now I can't get it back. I tried a clean uninstall/reinstall. Downloaded from the thunderbird site. Seems to install fine, but then says no profile recognized. I put some old profiles in the appdata\roaming\thunderbird\profiles in desperation, but still no luck. My clean uninstall did involve registry entries (Revo-Uninstall). So I'd like to get a clean start with Thunderbird, but it won't let me. Any suggestions greatly appreciated. I dread the idea of using another email after all these years!

Desktop Thunderbird no longer downloads mail from Yahoo though it did until 2 weeks ago or so. Now when checking for mail, I only see a "Local Folders: Checking Inbox for new messages" (screenshot) that eventually disappears after a while with no download. I can still send messages out from Thunderbird through Yahoo. I have done the "Please check the following before asking for support" : 1. I can log into my Yahoo account via the web and am using the same password 2. I only have one Yahoo account; all the other accounts work fine 3. I can send mail from Thunderbird through my Yahoo account with no problem 4. OAuth2 is active and can successfully establish a secure connection (screenshot) 5. Cookies are enabled with no exceptions (screen shot) 6. I do not use a VPN 7. Version is 151.0 (screenshot) 8. I checked the Error Console messages when Checking Inbox was active (screenshot) but do not understand it

I blocked out information on non-Yahoo accounts and email subjects on screen shots

As the topic says, the message list turned from the usual dark-mode look, to a full black background after updating to 151.0.

Was this an intentional change? How can I revert it?

Just what it says in the summary. I went to settings to check/change something, and found this new (I think) message in colour at the top of the page. I have no idea what it means, as I am not part of any organization. The statement is a link, and when I click on it, it takes me to the page shown in the image What if anything, does this mean? Do I need to do anything about it?.

System:

Win 11 Home (lastest updates, also my notebook's latest updates from the manufacturer) Thunderbird version 151.0

Okay, this is a multiple clusterf#@$.

I ended up needing to do a Win 11 Home "reset" keeping data. But I needed to back up some files first. But my back up drive was full. Usually, it's because of EaseUs ToDo not deleting files and just adding and adding to the system backup. But that wasn't the main issue: my Thunderbird profile (which I backup separately) was about 280 GIGABYTES in size! This is an extension of a prior problem for which nobody on here new how to solve and certainly nobody from Mozilla chimed in to help. So I did what I'd done before (but it'd never been like this) and delected a couple of THOUSAND seemingly redundant iterations of files from my profile, but NONE of the folders inside the profile.

Of course the Win11 reset deleted Thunderbird and all the profile information. No big problem, I've done this before...but it didn't work copying in all of the old files (from my backup drive) into a new profile and selecting that profile to boot. So, I went to the "Recycle Bin", undeleted all of those files back into my backed-up profile. But I'm only able to get Thunderbird to see all of my address book information. It is not finding my Thunderbird and email account settings nor my email messages (21 years worth). I 100% did NOT delete my email messages (c:\users\USERNAME\AppData\Roaming\Thunderbird\Profiles\PROFILENAME\Mail).

I can laboriously redo my email account information (five different accounts) and Thunderbird user settings, but I really DESPERATELY NEED HELP restoring my email messages.

PLEASE PLEASE HELP ME!

I can't turn off 'threading' of messages. I hate that feature. I'll do my own damn 'threading'. Now the 'search' function is useless. Help me turn off 'threading' I run Thunderbird which I like, on my HP Windows 11 laptop.

"Threading" cannot be 'unchecked' in the dropdown menu.

the morning I tried to access my email account on Videotron (I live in Quebec) and got this message from thunderbird "Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) .videotron.ca failed." Thunderbird was working perfectly yesterday. I contacted Videotron tech service and spent over an hour with the technician with no success. I have included two screen shots.

For the past several days, TB has not been downloading messages from Yahoo. When I click to download, it will say "downloading message 1 of 36" and then time out.

I get this message when I double-click the progress bar: "Connection to server pop.mail.yahoo.com timed out."

The settings have not been altered in any way.

I've looked through the various discussions on similar questions in this community and on Reddit, but none of the suggestions have worked.

Help please.