Thunderbird Community Forum

Hello,

I'm using Thunderbird in Debian GNU/Linux 13 (trixie).

Version: Mozilla Thunderbird 140.4.0esr

apt package: thunderbird/stable-security,now 1:140.4.0esr-1~deb13u1 amd64 [installed]

The last few weeks I started getting the problem that Thunderbird freezes, it stops responding and Debian (with the default gnome UI) shows a popup window saying "Thunderbird is not responding", then I wait for about 10 or 20 seconds, and then Thunderbird becomes responsive again.

Apparently Thunderbird is doing something that takes a long time (perhaps going through messages to index them for quicker search or something like that, I don't know), something that should be done in a background thread so that the program can remain responsive, but for some reason that heavy work is done by the main UI thread causing Thunderbird to become unresponsive.

This problem has gotten worse over the past few weeks, so I really want to do something about it before Thunderbird becomes completely useless. (At the moment I can still use Thunderbird for like 10 minutes in between the freezing, so it's not yet critical.)

How can I find out what Thunderbird is doing while the "Thunderbird is not responding" is shown?

For example, is it possible to configure some logging or performance profiling that would output to a file some information about where the program spends its time?

Other ideas about how to troubleshoot this?

I have been using both the new version of thunderbird and an older version that I prefer the looks. The older version I have set to disable updates and it still shows updates disabled by administrator. BUT, for some reason, this version has updated to the newest version. Any idea of how this happened?

To be clear, I seriously doubt the problems I am encountering are TB's fault! The problems may be my fault since I've grown older, I've tended (believed) using new versions of software present my mind a BIGGER challenge than using the older software/version I have been successfully using? I'm still using Version115.10.1

After our ISP chose to start using Zimbra Oct. 7, 2025 and their tech support could not assist me in getting TB working the had me remove POP3 settings for TB and change to IMAP with their software.

FINALLY someone helped me get TB working with IMAP. For 3 days grrr. Now the ISP says I need to use their web mail, Zimbra.

So might downloading the current TB version and somehow get the In box, all the folder contnets etc. over - into the new TB help?

I was going to backup everything tonight, now I have little to NO hope, without help!

THANKS & remain WELL plus be SAFE!

Robin

I installed Thunderbird on a Linux OS (Ubuntu). I have three E-mail addresses, configured them all taking detail info from other laptop (Mac OS) where Thunderbird works fine. I am receiving mail on all three account but can not send on any of my accounts. When I click on "+New Message" or the "write a new message" nothing happens. Any ideas?

For the third time now I have found messages I have saved in Local folders in TRASH. I did not put them there, and the original ones in Local Folders are empty. I have had to manually move messages intended to be saved from Trash into my intended folders. I am perplexed why this is happening, as I have not chosen Compact Folders or anything. Very, very annoying. If it continues I will search for another mail tool

On the 20, of October I was forced to re install Windows 10. Kept my data but I had to re install all my apps. With Thunderbird I follow the same procedure I used with Firefox: After installation I copied the profile folder from my backup and replaced the new one. That worked out well. With Thunderbird, I followed the same procedure, all my emails where there but not my local folders. I am attaching several snapshots to illustrate my steps. Image 1 "local folders now" Image 2 "Profile Folder". (why there are 2 sub-folders)? Image 3 "Mail in the profile folder" Image 4 " List of folders in my Local Folders" The are there, how do I get them back on Thunderbird in the correct place "Local Folders"? Thank you for your help again. Regards Ilio Pieroni

Why is this folder SO LARGE !!! C:\Users\xxxx\AppData\Roaming\Thunderbird\Profiles\6v2ccsvd.default-release\ImapMail

On my PC, it is over 3.5GB !

How can I minimize it !

10 Nov.

The version of Thunderbird I currently have on my Dell desktop is possibly corrupted. Dell Premium Support is trying to help me. I currently cannot send or receive e-mail through Thunderbird. Dell technician wants to install new version of Thunderbird. Then he wants to create a back up of all my current Thunderbird e-mail, and of all my local folders, including their contents. Then he would export the data from the back up and import it onto the new version of Thunderbird.

Please explain how to create a back up of all Thunderbird data.

I have read some information on how to create back up of Thunderbird Profile. However, this is apparently not a back up of all the e-mail itself, plus all the local folders and their contents. Thank you.

I was trying to change the time emails are kept on the server so I went into "Account Settings" and now Thunderbird is locked onto this page. I get a "Mozilla Thunderbird not responding" message when I try and click on anything and I can't get out of this page nor access my Inbox. I've tried starting Thunderbird in Safe Mode which didn't work. I then uninstalled and reinstalled the latest version of Thunderbird but when it starts it goes straight back to the frozen "Account Settings" page. I've checked my profile and there is a new profile that was created with today's date. There is also a profile from June 2025. If the old profile contains all my emails and folders up to yesterday, that would be OK.

I suddenly this week cannot send email using Thunderbird (v. 140.4.0esr (64-bit)). I receive email fine. I can send email using webmail with my provider. Error message in Thunderbird is: "Sending of the message failed. An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: resomta-h2p-555359.sys.comcast.net resomta-h2p-555359.sys.comcast.net ESMTP server not available (62240/216.183.125.238)." My provider says the issue is not at their end because my server settings are correct. Outgoing SMTP port is 465, connection security SSL/TLS. Operating Windows 11 v. 24H2.

I use Thunderbird to access my Hotmail account. I normally work on my Desktop Windows 11 system but have a laptop Windows 11 which I seldom access email with. When I just tried to update the laptop Thunderbird mail I eventually get the Thunderbird message "Unable to write the email to the mailbox. Make sure the file system allows you write privileges, and you have enough disk space to copy the mailbox". There is enough free space on my drive and it succeeded writing 10522 messages before it came to a halt. I notice that the desktop is at 140.4.0 and the laptop is at 144.0.1 and help says they are both up to date.

Since the Desktop mail is up to date it would seem the quick solution is to replace the mail folder on the laptop with a copy of the mail folder from the desktop. Will this be a problem since they seem to be at different versions. Version 140.4.0 on the Desktop and 144.0.1 on the laptop.

How do I get Thunderbird to download from two mailboxes in the same account?

My friend has an In box and a second one called Wrenches that was set up in his Zimbra webmail. How can he POP download both mailboxes? It's fine if the messages all end up in the IN mailbox.

I have installed Thunderbird on a new computer and copied my profile from the old computer as per instructions on the Mozilla site. However on the install on the new computer the LOCAL FOLDERS, sub folders which I use as archive storage do not contain the messages as per the my old computer. The sub folders are named correctly.

I have attached photos of the sub folders from the old computer showing data in the sub folder and also the new computer showing no data.

Please advise how to retrieve the data for the new computer.

Confused. Version 144.0.1 | Released October 16, 2025 Says 32 bit. I thought I downloaded 64 bit.

Problem: Freezes when I click anywhere on TBird desktop

How do I address the freezing problem?

Thanks Robert

with some changes with a default search for passkeys, I am no longer able to use thunderbird mail as is, as after spending three hours today, I was unable to add a 2nd account that has been accessed via gmail for a long time. I am wondering what other email problems other than thunderbird might have similar features,. as thunderbird has been rendered unusable by new code/passord, passkey requirements. I was looking at spark, but their interface is not as helpful. Thoughts! RIP Thunderbird mail, a long time friends, but time to move on, alas

I have an email account with BlueHost, which also hosts my web domain. A couple weeks ago I stopped receiving emails and contacted BlueHost tech support. The agent had no clue why I wasn't receiving email. She said "Can you please click on acocunt actions and remove the account and re-addd it. [sic]" I did that, and I was again able to receive emails. But then all my old emails -- sent and received -- had disappeared. BlueHost was able to restore my Inbox emails back to May 19, but was not able to recover any Sent emails. I have a backup of my Thunderbird directory from April, but would like to recover all of my old emails, which apparently still exist because my current Thunderbird Profiles directory contains files corresponding to deleted email folders. For example, my Inbox had a subfolder -- call it ABC -- that was deleted and is no longer visible in my Inbox, but I can find files ABC (no extension) and ABC.msf in my Inbox.sbd folder. My Sent.sbd folder also contains files ABC and ABC.msf. These folders are in C:\Users\aaa\AppData\Roaming\Thunderbird\Profiles\aaa.default\Mail\mail.aaa.com (with "aaa" representing my personal identifiers). mail.aaa.com contains files Inbox, Inbox.msf, Sent, and Sent.msf, which seem to contain my old emails. (Inbox is 132,151 KB and Sent is 289,829 KB, and the file dates are from a couple weeks ago, when I removed and re-added the email account.)

Is there a way that I can recover the old emails?

Downloaded the Thunderbird U.S. holidays to my calendar. My calendar is overloaded with miscellaneous and unwanted holidays. I've tried methods on the internet to delete them from my calendar with no success. I'm sure there is a method, but no success in finding it. Please help! Do I need to unistall Thunderbird and start over?