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Thunderbird has become crazy slow. 5-10 minutes to display an email. It's not my email server because my phone connects to and displays email fast. I have been through all the advice that I can find and cleared, checked, disabled everything that might slow it down. Still crazy slow. If I kill it and restart, I get about 3-4 minutes of reasonable performance and then it just stops. Latest Release Version V147.0.1.

i have a fast machine with 32Gb memory only 60% used, everything else runs fast

I don't want to junk Thunderbird, but it's unusable.

Help!

local folders after a certain amount of folders have disappeared. I have made a new folder today, it displayed, closed thunderbird, re-opened thinderbird, and folder disappeared, the .msl file and file are still in the profile/mail/localfolders directory, just not being display under local folders in program, deleted all .msl files, and restarted thunderbird, and it did not recreate the .msl file(s) as well

Lately, when I try to click on a different mailbox or message , nothing happens. repeating clicks sometimes works, and sometimes i have to first click on what I was previous viewing to get what I want to highlight, or click on different areas of a message or mailbox to get it to work. I am on mac tahoe 26.2. Did not have this problem before. What can I do to fix this problem?

Thanks Dan

I am having severe problems downloading and syncing my emails with TB 142.0. I opened TB this morning, for example, and it took more than 20 minutes for it to download my emails. When I go to the next email, it takes a couple of minutes to load it. I have had some issues with slow syncing before, but this is very bad. I note that the emails work fine on my phone. Also, this happens on my main Gmail hosted account, but also on my other Siteground hosted accounts. TB seems to be lost in some kind of loop when syncing.

I posted this question some time back but didn't receive any helpful answers and don't know where my post is. In the upper right-hand corner there is suppose to be 3 symbols. One to lower the app, one to make the app full screen or partial and one with an X. I have jumbled symbols where the 3 good ones are. It does it in trouble shoot mode. I tried disabling addons but I can't get the normal symbols back. Here's what it looks like... Thank you for any help.

For quite a few months now, Thunderbird has been acting weird. My emails download, I can sometimes open and delete some, but after a short time, it gets stuck on one email and won't open any more at all. I also can't open any menus, but I can change inbox folders, but still only the original email is shown. It's really hard to troubleshoot and try to fix, as I can't get to any of the menus most of the time. This happens in safe mode as well. This is getting really irritating as I've been using Thunderbird for many years, and I'd like to fix it rather than find a new email program.

Some websites won't load at all while other are very slow to load but some will load just fine, example Crunchyroll (screenshot attached) won't load at all its just spinning loading icon and a white page but if I try it in a different browser it works just fine, but with Youtube it will load but is choppy and low quality videos and same thing as before I load it in a different browser and no problems. I have tried every possible solution I can find from clearing cookies and cache to refreshing Firefox even scanned for malware and virus nothing has worked please help me figure out what is happening and why it's only with Firefox that I am having this problem and its not hardware can play online just fine and download games from steam perfectly fine.

Actually this is more an observation than a query, but I hope it's helpful. My Thunderbird V147.0 running two accounts on IMAP, Windows 11 and a lot of local folders (35Gb) had slowly got slower, but then just about packed up. e.g. 5 minutes to load one email, 20 minutes to download maybe 25 emails. Then it would stop completely requiring a Task Manager terminate and a restart. I read all the advice and tried a lot of it, but didn't see anything about the "global-messages-db.sqlite" file affecting performance. Anyway I got to having a look at it - 1.37Gb!! Deleted the "global-messages-db.sqlite" file and restarted. Thunderbird was back to normal and now 10 days later the sqlite file seems to be stable at approx 41Mb. I have no idea how it grew so big (33 times bigger than it seems it needs to be), I have never deleted it before and I have probably been using the current Thunderbird configuration for 20 years, but I imagined that reindexing etc would keep it a manageable size, clearly not. I wonder whether there should be a "Clear down Global Messages DB" button.

I recently updated to 147 and my email is not working efficiently. 1) Thunderbird will not open again after closing 2) Email header populates but message will not 3) All emails are in Inbox but none populate email message.

Help!

1. I've drafted an email, then hit save / closed the email and opted to "save changes". 2. I try to edit that email, but it is just "flashing" in the preview screen. I right click on it to "edit draft message", but that just brings up a blank email. 3. The status in the bottom left of the screen shows "loading message..." "downloading message", repeatedly. 4. It was working fine earlier in the week, but Thunderbird Desktop Version 140.7.0esr | Released January 13, 2026, seems to be when the problem started?

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.

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?

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 play games via android on PC using MuMu emulator, However the text becomesdistorted/cut off and little patches of colorful static patches appear when I scroll up or down. This is a problem on EVERY emulator I tried so far. This includes Memu and bluestacks as well as MuMu. They are ALL updated and I run the emulator using 8 core 16GB ram with DirectX and medium graphic settings. I tried low graphics and high and Max graphics all same issue. I tried using Vulkan and even the lowest graphic engine and SAME issue. This started happening after one of your updates but not sure which one because I just started using emulators again after many years of looking for emulator that does not bombard u with bloody Ad's..

Would appreciate it MUCH if you can fix this issue so I can use firefox to search for apk apps and games, I WILL NOT use anything that is based of Chrome aka Chromium (also a known in MANY verisons as a VERY dangerous and destructive malware/virus) and I also found a hidden remote access plugin on PC version too.

I been a devout Mozilla firefox user since firefox version was still in single digits, aka Ver 3.6 (example, I started at around Ver 5.x or 6.x hard to remember)..