Thunderbird Community Forum

When I open Thunderbird (Mozilla), my files are not current. In other words, the most recent emails, probably since the last time I used Thunderbird, in my file folders are missing. I have tried changing the server settings but I think they are correct. Please be patient with me, I am unfamiliar with all the terminology, etc. Also, when I first enter Thunderbird, it does not recognize my password. A window opens with the message "Login to server imap.postoffice.net with username john.fn@usa.net failed." That message also appears when I click on Get Messages. Thanks for any help.

Thunderbird 138/139, Windows 11 Pro 23H2. While composing a message, after a few lines the app freezes. Both the compose window and the main TB window freeze. Only opening the Windows Task manager allows me to close them. This did not happen with earlier versions.

If I save the message every few seconds while composing I can get most of the message back and continue after restarting TB. This behavior is the same in both the normal and troubleshooting TB modes. I can't even find a crash log to send to Mozilla.

Where shall I look next?

Thank you!

I am now getting a spinning wheel with annoying frequency while using/trying to use Thunderbird on my MacBook Air 2017 running Monterey. Everything was fine for the first 6-9 months, but over recent months the spinning wheel has appeared more and more frequently while I'm trying to read mail, answer mail, scroll through messages, etc., etc. Now it comes up every few minutes and delays me doing anything for about 15-30 seconds at a time. It's really frustrating. I recently ran Onyx, which was designed to clear cache, etc and make everything run smoothly. But the only program it required me to quit before it started was Thunderbird. Is there some cache or something I need to clear on a (semi-) regular basis to keep it working at a reasonable speed without this godforsaken spinning wheel interrupting everything? Thanks for any/all your help.

Have always set up accounts so they download all messages to hard drive.

Since 3/27/25, it is as if it never officially logs the downloads as downloaded, so it downloads each day as if it hasn't been done since 3/27/25, marking all of the messages since then as new.

File is very large so want to try fixing without deleting entire file.

Tried the 'repair this folder' but that didn't work.

Having trouble identifying the exact folder on the hard drive to delete since there are several different accounts in the Thunderbird setup.

I get a message like this every time I start Thunderbird. The topic came up last year but the conclusion was along the lines of "...this problem will be fixed in version 128" but it was never clear whether or not the User followed Mozilla's support replies or what they had to do to clear the email message from Thunderbird. .....Well I'm running version 128.1.1esr and the problem still exists.

My questions:

1. What is Thunderbird trying to do? Compact individual email files? Compae from ct the whole Thunderbird Profiles folder?

2. Is the problem the size of the Profiles folder or the overall size of the hard drive the Profiles folder resides on? What is the Hard/solidstate drive is the maximum?

3. Is the problem related to the amount of Free Space left on the Hard/solidstate drive or is the issue the number of individual files?

4. Is the issue related to the number of Thunderbird files and/or folders OR is it related to the total number of files and/or folders on the hard drive?

5. Is there a limit to the number of sub-folder levels that Thunderbird can navigate?

Thank you.

Tom

Tom O'Brien TOBrienArchitect@gmail.com

Thunderbird, quite suddenly, stopped getting my email; Both on my account and my wife's account at the same ISP. I spent more than two hours on the phone with the ISPs help line trying to resolve this issue. They also use Thunderbird at their help desk, and the agent I talked to was familiar with your program. She (the agent) was not able to replicate the issue on their system. We then tried to set up a NEW email account. I carefully entered all the info needed for a new account, following instructions from the agent, then hit the 'Test' button. I got the following message onscreen: "THUNDERBIRD FAILED TO FIND SETTINGS FOR YOUR EMAIL ACCOUNT" The answer to the original issue suddenly became very clear - Thunderbird cannot, or refuses to, connect with the email server, therefore NO EMAIL. We tried everything in her toolkit to resolve the problem to no avail. We finally tried UNINSTALLING Thunderbird (and the Maintaince program). Once Uninstalled, I used the Registry Tool on CCleaner to remove any entries in the registry referring to Thunderbird (there were several), then restarted my computer. I then downloaded and installed a totally NEW Thunderbird program. When I ran the Thunderbird again, I found all my account(s) info was still present, and Thunderbird was still unable to find the server. I'm at my wits end trying to resolve this issue, and REALLY HATE to go back to Microsoft OUTLOOK to get my email. Anybody got any ideas??? Any help would be greatly appreciated. (Signed) Proteus

I think it started to happen with Version 128.9.0esr | Released April 1, 2025. It is very simple to reproduce: 1. Start TB. 2. TB downloads new messages and continues to do it every 1 minute according to the setting. 3. In 10 to 20 minutes, it hangs. I have to force it to close and then restart it to check my email.

I believe it started to happen yesterday.

Is anyone else experiencing this?

I have used Thunderbird for years without issue. In the last 2 days, it keeps crashing on one of my laptops (fine on the other). I sent a crash report, but I can't reopen Thunderbird. I tried both quitting and restarting. I shut down my computer and restarted it. I tried updating by downloading the latest version, but that didn't work either. I completely uninstalled it, reinstalled it, and it worked for a few hours. Now, it is back to the Crash Report.

Any suggestions? I love TB and don't want to switch to something else.

Christine

Thunderbird is not synchronizing with Mailfence. My other email accounts (Outlook, Gmail) work fine. TB connects to them, downloads message headers and displays the number of messages correctly. With Mailfence, the messages stop at "connected to imap.mailfence.com" and stalls there. The message disappears after a few seconds and nothing else happens. This happened this morning when I first launched TB. I then got an update to 128.11.1. No change. I did receive the Windows Update 2025-06 Cumulative Update sometime overnight prior to launching TB.

Just upgraded to a new system with Windows 11. Avast Security. Installed Thunderbird 128.5.2esr same as on old system. Migrated old emails using MozBackup. Worked great for a day. New emails, archived a bunch of emails to a local folder...

Next day after about 3-5 minutes Thunderbird shows the Hourglass and is not responding. Eventually will go to a greyed out window. I have to kill it with task manager. I noticed that in Activity Manager three calendars were syncing for a long time. Disabled all calendars.

Task manager shows CPU usage but 0 Network and 0 Disk activity. 3 sub processes but only one has CPU. Resource Manager shows CPU and 72 threads. Resource Manager - Analyze Wait Chain - reports "waiting to finish network I/O."

I've tried Troubleshooting Mode. Still froze during Troubleshooting Mode. I've tried moving a large local folder out of the mail folder entirely. I've tried clearing the startup cache. I've tried clearing the system temp folder.

I have a lot of accounts, saved emails and message filters. So I really don't want to start over again with an empty Thunderbird and reset up accounts.

The 'Sent' file in my 'Mail' folder exceeds 3 GB (3,224,360,399 bytes) and is not being read in the TB Mail window. How can I reduce the size of this file AND save messages???

'Sent' message folder IS searchable!!!

I was using Thunderbird for Windows 10 normally for many months. Recently, whenever I launch the app it immediately freezes, and I have to force quit the application. Reinstalling the app does not fix the issue. I haven't tried deleting my profiles yet, but I would like to avoid that if possible.

Am getting this message along with a recurring download of a specific email (keeps coming back even after deletion) that does not allow any other new messages to be downloaded. I do see new emails on my phone but will not read into Thunderbird??

Error: "Unable to write the email to the mailbox. Make sure the file system allows you write privileges, and you have enough disk space to copy the mailbox."

Tried: Troubleshooting, closing Thunberbird and reopening, rebooting windows system, compacting, etc. to no avail....

I've been having issues with Thunderbird randomly hanging over the last few weeks. It's always been slow to upload all my gmail messages, so I let it get done with that before I start reading. However, now it randomly decides to hang forever. It generally happens when I delete or move an email to another folder. It doesn't complete the function. I can click on other emails, but it doesn't open them. The UI just sits there with the blue progress bar shimmering away, forever. None of the window control work (File, X, etc.). I have to use the Task Manager to end the Thunderbird task. When I start it up again, the message will be moved or deleted, and I can view more messages until it decides to hang again. This happens about four times per day.

I have an MSI GS75 Stealth 9SF laptop, running intel Core i7, Windows 11 (up to date), and the most current version of Thunderbird.

I didn't see anyone else commenting on Thunderbird hanging frequently, so I'm wondering if it's just me.

1. Thunderbird was not my default mail client in Windows. When I tried to select it as default it did not appear in Windows' list of applications.

2. I tried to find the my profile and it showed where it was - but that directory did not exist. I finally was able to make a new profile and the directory showed up - but then the default-esr profile disappeared and now I can't find it and neither can Thunderbird. Is there a way to find where it went? I don't believe I delete it, it just went away. This is the message I get:

Your Thunderbird profile cannot be loaded. It may be missing or inaccessible

Thunderbird had never crashed before, but lately, after the last 2 Windows 10 updates within the last 2 weeks, it crashes. It's at 128.5.2esr, the next-to-last update.

It always crashes when I choose "About" and it starts downloading the update. It appears that it doesn't get the 1st byte before crashing. It will still say 0 bytes when it crashes.

It also crashes if I leave it running and the screen goes through the screen saver mode and turns black. Twice it crashed while I was using it.

I thought it might have something to do with the fact that I had 4,000 emails in my Inbox (is there a limit?), so I deleted many and moved many to folders. I now have just under 1,000 in my Inbox.

I also tried restarting in Troubleshoot Mode and updating, but it still crashed at 0 bytes downloaded.

Is there a way to manually download the update and apply it? I can't find it on the website.

The next thing I know to do is reinstall. Is there anything I can try before doing that? Would you suggest uninstall first or reinstall over what's here?

I have a new Macbook M4, and installed Thunderbird 128.6.1esr as default email application.

If a new message comes in, suddenly a white square appears in the upper left of the desktop, and Thunderbird becomes nonresponsive. If I close it, it won't reopen. If I click the white square, a truncated Thunderbird menu appears at the top. See screenshot.

Also, the white square overlays all other running applications, so that anything full screen has the red and yellow close/minimize buttons hidden.

This happens whether Thunderbird is the only application running or if others are running.

It is driving me mad. Any insights how to fix it?

Hi, tbird 128.3.0 esr 64b w11p. A prob new to me. Only for MS outlook mail (aka office365 email, but no ofc365 on my laptop, just the email in tbird). -in unified folder view, my MS mail acct (it still has the "hotmail.com" address, but works), is not present -- that's the problem. A workaround is that I can choose both "unified" and "all" views together -- but while the MS mail acct now appears in the folder pane at the top, as well as in its own "place" at the "accounts" area below, that MS mail acct not longer has its messages appearing in the "message list" pane. I have to go to MS Mail's own place below, in the folder pane (as stated above),to see its msgs. in msg pane.

 I could use the "all" view, but it's not as nice & I never have had to choose that before this prob.

- I did run "repair folder" for MS mail's own inbox (again, below, in its own place below, in folder pane, accts). And I restarted t-bird.No change in behavior, unified view does NOT list my hotmail emails.

I have used & am comfortable w/config ed, but only when I have the proper instructions you may post in your potential reply (I am not a coder).

Please advise, thank you.

One of my TB accounts has two archive folders, one named Archive and one named Archives. The Archive folder has nothing in it while the Archives folder has several years of messages in it. How can I delete the non-functional Archive folder?

Hi,

I'm on a fresh Windows and the CPU usage is waaaaay too big. When TB is out of focus, it uses about 10% of my CPU. This can go up to 15% when the window is active. It's not doing anything, not downloading or compacting or anything.

Thanks !