Thunderbird Community Forum

Why is everything running so poorly? The right-click function does not work. I have also tried to use various features, but the drop-down menus are not accessible. I cannot even mark something as read. The right-click function continues to fail, and I was also having trouble accessing help or using the Help function at all. I had to close and reopen the program just to get here. Something has clearly been wrong in this regard over the past week or so.

The folder 'Outbox on Local Folders' could not be compacted because writing to folder failed. Verify that you have enough disk space, and that you have write privileges to the file system, then try again.

Keep getting this message: "The folder "inbox on [email address]' could not be compacted because writing to folder failed. Verify that you have enough disk space, and that you have write privileges to the file system, then try again."

I have tons of space, but I don't know which folder you are referring me to. Does it have a name? Does it reside in a specific subfolder? Can you give me some hints to locate the folder? Is this really the problem, or does the message indicate something else is amiss.

Thanks, Don

I am experiencing a severe problem with Thunderbird. There are several symptoms: 1) The CPU utilization of Thunderbird is typically 13-19%. 2) Thunderbird declares that it was able to send a message and to save it, but that it experienced difficulty when running filters. 3) Thunderbird is unable to compact a folder. The message received is:

   The folder 'Inbox on william.atwood@concordia.ca' could not be compacted because writing to folder failed.  Verify that you have enough disk space, and that you have write privileges to the file system, then try again.

4) Thunderbird occasionally gives the following error message: Your message was sent but a copy was not placed in your sent folder (Sent) due to network or file access errors. You can retry or save the message locally to Local Folders/Sent-william.atwood@concordia.ca.

These are the symptoms that I see today. Over the longer term, I saw the following:

1) Thunderbird started to behave strangely several weeks ago. It somehow lost track of what messages it had downloaded, so it started downloading all of the message headers in my inboxes (and other folders). (I have six email accounts that I monitor.)

2) Since all of my accounts are IMAP accounts, with the messages stored on the server, I tried replacing the Thunderbird profile with a copy that I had previously backed up. This seemed to solve the problem for a short time. However, the symptoms soon re-appeared, including high CPU utilization, inability to compact folders, and difficulty running filters.

3) At the suggestion of my employer's help desk, I removed and re-installed Thunderbird. This found the existing Thunderbird profile, and everything seemed to work just fine for a few days. Then, suddenly, everything went haywire, and Thunderbird started re-loading all of the message headers for *all* of my folders (and for all of the accounts), and complaining about inability to run filters or compact folders.

Finally, Thunderbird crashed today. I added notes to the crash report, giving some of the details above. After it restarted, it crashed again. I finally ended up restarting my computer.

Thunderbird version 140.0.1 Windows 11 Edition Windows 11 Enterprise Version 24H2 Installed on 2025-04-30 OS build 26100.4349 Experience Windows Feature Experience Pack 1000.26100.107.0

What can I do to mitigate this problem? It is very difficult to use Thunderbird when it acts like this.

Bill Atwood

Hi. I have over 20,000 messages in my Inbox. I've been sometimes having trouble moving messages into folders, so I thought it would be a good idea to reduce the number of messages in my Inbox. But I can't delete or move messages in the Inbox. When I select messages and enter command to move them to a folder, or ask to delete them, nothing happens. I am a Thunderbird supporter, and I love this program. Thanks for your work! Any advice appreciated. Connie

Here's the error message:

The folder "Inbox on tomhelm@sonic.net" could not be compacted because writing to folder failed. Verify that you have enough disk space, and that you have write privileges to the file system, then try again.

I think I have enough disk space. But how do I verify that I have write privileges to the file system?

I use Thunderbird on Windows and on Mac. I'm wondering why the startup time on Mac is significantly longer on MacOS. I'm currently on Tahoe 26.0.1 but Thunderbird has always been a slow starter. Can I change any setting to remedy this. At the moment I have two mail accounts configured both Gmail.

I have been having trouble for awhile now with the preview pane not changing with a message archive, delete or even a new message arriving. The only solution I have found that works is to turn it off/on with F8. Have tried updating (currently on 140.6.0esr), unified folder debugging, and setting thunderbird to download complete message not in bits on AI suggestions. Doing same thing on laptop and desktop. Gmail, yahoo and outlook accounts. It seems to only happen when using the unified inbox folder. Cannot find any reports here in forums, but AI says it is a common complaint. Is there anything I am missing to try?

Thunderbird very slow to respond when opening the program. On opening any email it freezes for a couple of seconds resulting in a "Wait for the program to respond" or "close program message" . This also happens when performing any action in Thunderbird. This has been happening for the past two or three weeks. Can you tell me how to fix this or is it something you need to do to fix.

I have been using thunderbird for a few years now on win 10. Just had to buy a new win 11 system and successfully installed it. transferred my emails, folders and contacts and all seemed to work fine. Now I notice that once I leave it for a few mins, it is unresponsive with just a blue circle where the curser should be. I close it and re open and all is fine again for a few mins. I have tried turning off my antivirus software and disconnecting from the internet but still the same fault. Any ideas please?

I was happily using TB 78.14.0 on Mac OS 10.9.5 and I switched to using TB 140.6 on Mac OS 12.7.4, and it's now unusably slow. I've tried: troubleshoot mode with add-ons off; compacting folders; removing and renewing msf files; emptying junk and trash. Is there anything else, or is this just a failure or incompatibility of the app? I can't see that there's any antivirus app that might be interfering. Can something go wrong when you export the files from one TB into another? I would be grateful for any suggestions. Tim

Hello,

I have a MacBook Air M2, and I'm experiencing energy usage issues related to Thunderbird. This has kept happening for a long time now actually, surviving through at least two Mac OS updates, and a huge number of TB updates. Everything's up to date. I tried to follow this: https://support.mozilla.org/en-US/questions/1269944 and this: https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems?_gl=1*86dj4d*_ga*MTkzNzQ0MjA3MS4xNzYyOTY4OTMx*_ga_2VC139B3XV*czE3NjMzMTM3NDckbzIkZzAkdDE3NjMzMTM3NDckajYwJGwwJGgw but didn't succeed. Actually, in my case, the issue is more noticeable: I normally have TB open in background - sometimes everything's fine, and the battery goes down as normal, while sometimes instead the battery drops quickly, and checking in the Mac activity monitor I can see that the CPU usage of TB is totally abnormal. When this happens, I can actually see the activity bar in TB being live (bottom right corner, as it happens when TB is checking for new mails), but never disappearing. When I notice it, I just reboot TB, and the bar shuts off as normal after a quick mail check. Moreover, checking the 24hr energy usage by app, TB is often on top with nonsense values.

I tried multiple times to rebuild the database, and do most of the tricks suggested, but didn't fix. Yes I have a huge mail archive, but the problem is not the standard management of this database: basically it seems that every now and then, TB decides to run some activity which it gets stuck in, and this kills the CPU.

Thank you in advance for your help!

Thunderbird version: 146.0 Platform: Windows 11 Email Provider: Google workspace

I'm slowly persuading my wife to move over from outlook to Thunderbird (due to constant issues with google sync). I've got it all setup nicely and working BUT i'm having a real issue with the thunderbird calendar taking an absolute age to populate It is quite a well used calendar with lots of recurring events/reminders to pay bills etc. Just to get the Holidays in United Kingdom takes about 30 seconds and to populate from the gmail calendar takes around 8 minutes

It's the one stumbling block i'm finding to persuade her to move over so any advice that can be given would be greatly appreciate

Imagine having more than 30 Accounts to be added on a single profile my concern is how will Thunderbird handles file size if it's using one file (MBOX) and if the file has no solution, can I create files and keep mails on them until they reach max size?

Config editor has no printer listed. nothing to reset. Printer works with other applications just not TB. Re-installed the printer. Reset the space limiters, which I found were set too low. Restarted TB and computer

I have two installations of Thunderbird on two different computers 2 different locations, both are new installations. Both are on Windows 11. The one at home, works perfect, the one in my second home too except the unified toolbar is unresponsive, whatever I click there it doesn't respond, The X doesn't close the program, the - doesn't minimize anything, just nothing happens, any advise?