Thunderbird Community Forum

Why Thunderdird now is so slow

Why you recommend to upgrade to ESR when the one that I had been using for years I don't trusted

I have Thunderbird: 128.10.1esr (64-bit)

Amparo

Hello, I am unable to see my email messages in the panel. I do see the number of emails that I have, but unable to open anything. Has something major happened with Thunderbird? The email function was working fine and the next morning, all of my messages in the panel disappeared.

I'd appreciate any immediate feedback. Thank you.

I am having a problem with my thunderbird email client. There was an update to the program over night and now when I load thunderbird it is unable to show me the content of emails in any of the folders. I can see the emails in the list and all the folders are shown in the folder tree on the left. Howevr I am not able to access the content of the emails. My thunderbird profile folder is on a network share, this fileserver is a windows based machine. If I copy the profile to my local machine the profile works correctly and I am able to open emails and view the contents. It is only when my profile is on the network that I cannot view the contents of the emails. I ran thunderbird in safe mode and this does not resolve the situation. I have tried to repair the folders but this did not work. I deleted the .msf files but this also did not work. I ran the thunderbird debugger and then tried to access an email, the debugger stopped on the follwing exception: NS_ERROR_XPC_BAD_CONVERT_JS: Could not convert JavaScript argument arg 0 [nsITreeView.setTree]. What could be the problem with my emails?

I have used Thunderbird for many years and and have loved it. However, recently my "Local Folders Inbox" have been extremely slow (deleting emails, reviewing an email, etc.). I have tried every suggestion that I have found without any change: reducing emails in the folder (down to about 75 remaining), compacting and repairing the folder, deleting and rebuilding all of the msf files and global database, disabling all addons, empty trash and junk, clear the cache, disable hardware acceleration, exclusion in antivirus, etc. It has become very frustrating. Any suggestions would be greatly appreciated.

The last couple weeks any emails from a business only have red horizontal/vertical grid lines. If it says to view or track package it won't let me, do it. If I drag that email over to another folder it acts normal and if I drag it back to my in box it has the red lines. I've checked the emails in the server, they are normal. Also, there is yellow bar at the bottom of the attached email. It acts like a message I'm trying to send because the to is prefilled out with my email address. Weird Dell Inspiration 366B Ram 8GB 64-bit operating system Windows 10 V 22H2 Thunderbird 32-bit 128.9.0 release 3/18/2025

Thunderbird keeps coming up with the message: The folder 'inbox on dveitch@202.215.17' could not be compacted because writing to folder failed.

There is plenty of disk space and compacting has been working fine until recently. Has a Thunderbird update changed something?

I am running TB. Using the Windows Performance Monitor, the usage jumps from 30% to 90% and then 100% once TB is open. I am running 1.128.14.0esr (64-bit). I have the before and after screenshots of the CPU, see attached. Is this known behaviour?

I tried the steps at https://support.mozilla.org/en-US/kb/profiling-thunderbird-performance to record. The Multiprocess Browser Toolbox window hung the 2nd time (the first time, nothing happened after Capture recording), then I left it 20 minutes and came back to the message that we were unable to connect to the browser within 30 seconds. It eventually finished, painful - htpps://share.firefox.dev/41tZ5xy

TB has started to exhibit terribly long latency lags

I'll be working on TB, and then it hangs for 5-10-15 seconds, if I click on a new feature, the screen goes gray until the latency resolves. Also get the Windows timeout error notice (see image)

After 10-15 seconds, TB resolves on its own and works OK for a little while, but then goes latent again after maybe 1-2 minutes. This is consistent last couple days. I've rebooted, cleaned caches, etc.. and the rest of the Win 11 PC is working fine, fast, no latency in any other program.

I asked my email providers if they were having IMAP issues, but everything OK on their end.

Ideas? TB v. 140.11.1esr (64-bit)

Hi! Since a few months, I face the problem that Thunderbird stalls and is inaccessible for several seconds (>20) when a screen refresh happes or sometimes when for example a windows message pops up. I disabled/ininstalled all add-ons and also have reset all setings to their defaults. Has someone the same problem or has a hint for me? Thank you!

Hi to all ! On a MacBook Pro under Sequoia 15.3.1 whenever I launch T'bd (128.8.0esr) it opens but accepts no command and the message screen is empty. The CPU usage is about 25%. Nothing else of importance runs on the computer. The same happens sometimes in the middle of a session. I removed Norton 360 just in case: no help. I could not correlate this behavior with any change I or the software updates did (it worked perfectly well until ~end 24). When I wait (15-30 min) and the messages finally appear. I tried killing an relaunching T'bd but it does not make much of a difference. Would someone have an idea where I could search to solve that? Thanks in advance for any help. Max.

Thunderbird 140.7.0esr (aarch64) on macOS26.02

For several days now, Thunderbird has been responding extremely slowly to mouse movements or clicks. This leads to undesirable results because emails are suddenly deleted that should not be deleted (due to forced double clicks). Or folders are not opened, or the wrong folders are opened.

The last change was updating Thunderbird. Is this a known bug?

I have 2 Windows 11 laptops running Thunderbird. Retrieval of POP3 account email takes 10 times longer on Windows 11 as compared with Windows 7. I have 13 different email accounts. If there is nothing new to download, my windows 7 computer takes 5 seconds to check all account. Windows 11 takes 50 seconds for the same task... clunking along very much slower. I have tried many approaches to tracking down the cause of the slowness. Antivirus software (Norton 360) and various Thunderbird and system settings. Nothing makes any noticeable difference. I'm at a loss for what to try or even to finding anyone discussing the same issue. I have been using Thunderbird on at least 4 windows 7 pcs with no such issue. Both my windows laptops have the same clunky slowness. I want to move to windows 11, but this is holding me back. Is this just inherent to Windows 11? Any ideas would be appreciated. Thanks

As email threads become lengthy they become unreadable. The older emails turn into displaying one character per line. Is this a bug or something fixable on my end?

This is an odd one I've not encountered before. I have TB installed on 2 laptops at home. They are up-to-date with 128.6.0 installed, and both are using the same wi-fi system.

All of a sudden a few days ago, TB on one of the laptops, but not the other, became noticeably slow in deleting messages. It now takes a few seconds for what before always happened instantly (and still does on the other laptop).

Not the end of the world but it's annoying and I'm hoping there's an easy fix.

Thanks for any help.

Andrew

My green "New Message" button has stopped working for some reason. I've tried switching it off then back on but it still won't work. so at the moment I can't create new emails. Regards William

Downloading emails works quickly as normal but reading opening or looking at emails (even ones downloaded weeks ago) is suddenly very slow. There is a pause before anything can be viewed even with a preview screen open.

Version is 128.7 0esr I use bitdefender - but that has never been a problem before Any ideas?

Start up has been lagging for the last 2 weeks or so. When I open the program I see "no emails found" and the circle of death. I have to wait for 20-30 seconds before my email accounts show up and again while they download. Anyone else having this issue or is it just me?