Thunderbird Community Forum

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.

Hello,

Scrolling vertically with mouse-wheel in Thunderbird is uneven and unstable, while scrolling in Firefox* is perfect. (*or any other program) What could be wrong?

Thanks, Mark

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 !

Aloha, I have been using Thunderbird since decades. Since a few weeks (or even months) by now, it is hanging all the time. Meanwhile it is totally impossible to use it properly. Whenever I klick on something it hangs itself up and I have to wait at least a minute until I can click something else and then it hangs again.

I already tried reinstalling, but that didnt change anything. Of course I also rebooted the computer.

Why is that so and what can be done?

Mahalo, Stefanie

I am constantly getting Security Exceptions. I need this to stop. Immediatly. I am fed up to the back teeth that every time I open Thunderbird I have to close it and start again. Then I get another one. See attached photo. Please make this stop. Now I can't even attach a photo. Can some please tell me how the hell I can get this stop.

Sometimes message pane box got blank on one or two of the messages. I tried disabling hardware acceleration, did not help. I can clear by restarting Thunderbird. What is causing this? I am on a Mac M2 processor.

I exported Outlook Contacts to a .csv file and imported giberish to the Thunderbird Personal Address book. Can the giberish be block deleted? How should the Outlook Contacts be transferred to Thunderbird? Secondly, I exported Outlook Contacts to gmail and have used them on the web based gmail app to send messages. Don't remeber how the gmail contacts got to the Thunderbird Address book, but they don't work. The first message I sent from Thunderbird from my wife's gmail address to my hotmail address produced the following error:

Sending of the message failed. An error occurred while sending mail. The mail server responded: The recipient address <Steve Thompson (sthompson2486@hotmail.com> is not a valid RFC 5321 address. For more information, go to

https://support.google.com/a/answer/3221692 and review RFC 5321

specifications. 00721157ae682-70ca8508772sm13401897b3.82 - gsmtp. Please check the message recipient ""Steve Thompson (sthompson2486"@hotmail.com" and try again.

Both imported address books are unuseable. Please help.

Need help with Thunderbird. No matter what I tried always comes back to the same problem.

Problem: Keep getting message non responding. Very buggy, difficult deleting emails (will delete after a prolong period of time > 5 sec). When typing a message there will be no characters then after a short period of time the charterer typed shows up. Sometime without and reason while using Thunderbird it close by itself.

What I have down to solve the problem: 1. Start in safe mode Thunderbird operates as expected with any issues. 2. Win 10 environment, closed all apps and made sure there was no extensions running. Made sure the only app open on the task manger was Thunderbird. NO SOLUTION FOUND 3. Download and install latest version of Thunderbird. NO SOLUTION FOUND 4. Created a new profile file. NO SOLUTION FOUND

Need help, what else is there to try short of a total Nuclear solution?

сегодня столкнулся с проблемой, что не могу создать учетную запись, используя домены от mail.ru. на скриншоте показал результат моих действий: я как обычно ввел почту, поставил пароль, заранее в самой mail почте разрешил использование imap, а когда нажал готово и разрешил доступ в самом thundebird, то окошко с входом просто закрывается и пишет "не могу войти на сервер", хотя я даже не ввел пароль. это происходит со всеми доменами типо inbox и т.д, с gmail все работает нормально. помогите пожалуйста

Hello,

I am a long time user of Thunderbird and recently it seems like it is really dragging, especially when searching for emails. I am updated to 128.6.0esr (64-bit). Is there a setting I can adjust?

Thank you much!

Regards, Eric

When I right-click with my mouse to open options, all I get is a small rectangular box with no text in it, and I have to use the toolbars to activate the options I want

Problems with connection to Xfinity email. Will not connect when using the windows desktop version. I have no problems (currently) with the mobile version. both have the same setting but for some reason the Desktop version will not accept the password provided. Cleared the cache on the desktop and still no connection to xfinity. connection stopped 6/2/2025 around noon eastern time US. Any suggestions?

I've been using Thunderbird for about 15 years. I just downloaded and installed V139. Thunderbird is now unusable. In the past, performance was great. Downloading email was fast and my filters moved the messages to the appropriate folders with no issues. With the current version 139, downloads take up to 5 minutes for only 4 or 5 messages. The filters run incredibly slowly. I can't scroll either the navigation pane or the preview pane or the messages pane. Version 128.11.0esr runs just fine with no issues on my other system. Both systems run Win10 at the same maintenance level. After all these years, I don't want to change email clients but if this situation doesn't resolve, I'm afraid I will have no choice but to toss Thunderbird in favor of some other solution.

How do I get back to version 128.11.0ser for this system?

Thunderbird has become a pain now for a number of months- regardless of any updates. On first start up if I click on anything on Thunderbird before ALL email accounts have completely finished downloading, Thunderbird locks up and displays not responding on the top of the screen. I have to wait ten minutes and longer before I can start reading a email until every email on every email account has finished downloading. When a site says it is sending a verification email - before I can see that email when I start Thunderbird - the verification email needs to be resent because it has run out of time. This never happened a year ago - now it is daily! I don't know what Mozilla is doing to Thunderbird but it is now highly unreliable! If it was not the only free email client software I would have dumped it by now. Why is it doing this?

I have no idea why, but TB is wonking out lately with strange errors?

The folder '[Gmail]/Sent Mail on me@mydomain.com' 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 a ton of space and have not changed anything on the PC?

Any ideas?

Unless I shut down Thunderbird on my main email account, it will open with the last email account read. There must be a way to set this to open every time on a specific email account but I am yet to find out how to do that. For example - email account FY@gmail.com is what I want to show when Thunderbird starts - but unless this email account was the last read before it was shut down the last time - it only opens on the account last read before it was last shut down.

How to set this to a specific account when Thunderbird opens every time?

I run a small network using a synology NAS. I have Thunderbird as an email client on each of my lap top and a desktop which mainly serves as a backup and when I need more power. Consequently Thunderbird on the desktop does not often get used and falls annoyingly out of date because the respective profile folders are stored on the local machines. I do not want to store the profile folder on the synology NAS because this would make thunderbird unusable if I am away from the LAN. (out of curiosity would this work anyway)? I do not want to make the NAS directly accessible from the internet. Would it be possible to synch each profile folder, ie laptop/profile and desktop/profile to a profile folder on the synology drive ie synology/profile such that the profile folders will all synch when any one of them is connected to the NAS? Thank you for the help.