Thunderbird Community Forum

Thunderbird is very glitchy and slow after the latest update - Thunderbird 140.11.1esr (20260522210329)

Especially, when I get a new email, Thunderbird stops responding for 5-10 seconds and then starts working.

I am using Windows 11

After I open my Thunderbird email and use it for 15 to 20 minutes it freezes. I need to close it and I get a message Thunderbird is not responding. I then need to close the program using Microsoft to close the program.

Other than being slow to download my emails now for a few months, TB was performing well until a week or so ago. Now it also won't open the downloaded email when I click on it and the TB freezes up so I can't close it out. I have tried restarting computer multiple times and it works for one or two emails that I can open and then starts freezing up again. Makes using it almost impossible. I have security Windows 11 Defender only and have had it the entire time when it also worked well.

roland.multhaupt

18. Juni 2026, 07:13 GMT-6

Firebird is so slow now, that I can rarely receive the code that you send me. Have to take annother programm for that. Freezes even when trying to mark a mail or erasing it. WIN 11. The programm is working well at my wifes laptop also WIN 11. 2 month ago it worked fast and fine. Working in Troubleshooting mode does not show any spam ordner like before and it does not run better. I also downloaded the last version. No change! I would like to uninstall the programm but did not dare due to perhaps loose all my mails. Could you help me please? Thank you!

Hello, It's been a few days Thunderbird freezes when I want to save a message on the computer (save as). When I close the saving window which is not responding, it automatically saves the message on my desktop. The file where the last message was successfully saved is still existing so I don't think it is a path problem. I have tried to restart it without the add-on but it doesn't change anything. And it is up-to-date. Anyone knows what the problem could be? Thank you! Estelle

On Sunday, May 7, my Thunderbird program suddenly stopped responding (neither the shortcut nor the program itself will run); clicking on the shortcut icon or attempting to open or run the program itself causes the "loading" or spinning wheel icon to pop up, run for about 10 seconds, then stop.

I've used Thunderbird as an email client for my Sonic email account on my pc for over 8 years without any difficulties until now, and now seem to be locked out of my Thunderbird account. I cannot access it to confirm the version, although I believe it is current, since it appears to update automatically.

My Sonic account continues to function normally, but I keep (save) all incoming and outgoing emails in my Thunderbird system and now am unable to access any of those, and unable to access my Thunderbird account at all..

I've consulted with Sonic over this; Sonic maintains that any difficulty must be on my end connecting to Thunderbird, and suggested that I might have changed the account password. However, I have not changed the password, etc.

Please help asap.

Thanks, immensely.

Tim

My machine Intel i3 6100, 16g of ddr4, windows 10. 250 gb ssd +1 tb mech hard drive

Over the last week or so, I call up Thunderbird then when I click on anything, it just comes back "Not responding" Any ideas?

Thanks in advance Tony Sneath

I have a Dell Desktop with 64GB Memory, Windows 11, Intel Core i7-7700 @ 3.60 GHz, 1TB ssd, and two additional drives. On a new installation of Thunderbird 152.0, I get "System Integration" (Not Responding)" window. The only option is to exit. What can I check to correct this. I have uninstalled and deleted the install file multiple times with the same result. Thank you.

multiple copies of emails, usually old ones, cannot delete them, also cannot open new emails, often thunderbird freezes, message comes up that thunderbird not responding

I posted this earlier and the bot named David is trying to take over with ideas that don’t work. How do we stop it? I also posted from my own email and it tried to stop me.

This is Ellen. I tried restarting Robert's ( my late husband) computer after it crashed and I got the message about Thunderbird's inbox folder not being able to be opened because it is in use by some other operation. It is an old Mac Mini running 10.13 and it says TB is 115.18.0. I don't update it because I don't think his OS can handle anything newer. I just looked and my Mini with an M1 chip (4 y/o?) is running 140. something.

How do I get it to quit whatever it is hung up on? His email is coming in ok on my iPhone.

Robert was a sculptor who made large kinetic works and a lot of his work is still on this computer.

Please help me get out of this mess. I think it has happened before.

Ellen

I have been using Thunderbird for years with no problems. However recently, Thunderbird very often simply stops responding. Sometimes it just hangs up and sometimes the program bar at the top displays "Mozilla Thunderbird (Not Responding)". If I try to wait for it to respond, it literally hangs for several minutes before it begins to respond again, and often, it simply never starts responding again. It has simply gotten to the point where Thunderbird is practically unusable. All my other application software continues to work with no problems. It's just Thumderbird.

The version number in this submission may not be correct. I can't provide the real version number because of the hangups.

Any suggestions?

Thunderbird keeps locking up. I have twice uninstalled and reinstalled, yet Thunderbird still locks up with the processing message. At this point, I want to know if 1) there is an online interface that I can try, and 2) If my emails can be salvaged somehow.

I tried the troubleshooting tips on the web, but I can't even get into the folders, even in troubleshooting mode.

Good morning

Since this morning (05/03/2026) Thunderbird freezes within a minute or two of opening the program.

Everything in the program freezes up. I cannot even close it.

I am running Version 140.8.0esr on a Windows 10 PC.

Initially I was getting a pop up warning message that ask me to confirm if I wanted to send an email with attachments of over 20 MB. There were 3 or 4 such messages. I had not tried to send such emails.

I checked the Outbox in Local folders for old messages, but it was empty. I also checked the Unsent messages files in Local Folders in the Profile folder. I deleted the Unsent Messages.msf file to no effect. I renamed and replaced the Unsent messages file. Also no change.

I checked for crash logs but there are none.

I have run out of ideas as to what to try next. Does anyone have any advice?

Running windows 11 Pro and in the last microsoft update my thunderbird email is not responding at all. It is trying to connect to imap.gmail.com.

How can i turn off auto account checking on startup so i can access my email settings to try and fix this?

I tried running it in safe mode and i get not responding there too! Can i access a profile folder and turn off auto email checking somehow?