Thunderbird Community Forum

I have been using Mozilla Thunderbird for decades and they have even contributed a small amount of money to Thunderbird periodically. Just within the last two or three days all of a sudden I have been unable to send emails with my phone. I receive emails, but I do not send them. So I opened up a laptop where I did not have Thunderbird and set it up properly through Spectrum using the incoming and outgoing servers as mail.twc.com. and yes, just like on my phone. I continue to receive new emails, but even with the laptop I was unable to send an email. I received the message"send message error sending a message failed. The message could not be sent because the connection to outgoing server smtp mail.twc.com was lost in the middle of the transaction. Try again."I contacted Spectrum twice and both times they had me try to send a message through their Web server spectrum.net and that message did go through. Of course then their response is that this has to be a problem with the third-party app meaning Mozilla Thunderbird, and they can’t help with that at all. I sure would appreciate some help because I hate to walk away from Thunderbird as well as change my email address after all of these decades.

I recently booted up a new installation of Thunderbird on a new laptop running Fedora Linux after my old Laptop running Ubuntu died. Fortunately, I had been regularly backing up the old machine with Deja Dup. I restored all my files from a recent backup. All my files seem to have been successfully recovered except that many locally-stored Thunderbird messages are missing, and some local folder names have been corrupted.

Since I see problems only with Thunderbird, I suspect the problem lies there rather than with Deja Dup.

Has anyone else had problems with restoring Thunderbird from backups? Is there something I might try to recover the missing messages and corrupted folders? Should I be using a different backup in the future?

I had just started utilising Folders. Today I wanted to move an important email where I could easily find it again. I created a new folder, went to the inbox, clicked on the email in question and moved it to the new folder.

Then I went to the new folder to check that it was there safely and it was and I shut down my laptop.

Later I got home to start work. I looked for the file and the folder was empty. I ran the search that I had run previously and it now returned nothing found. The email had vanished.

I moved some rubbish emails to the same folder, none of them arrived there, all have disappeared and are not to be found in the deleted folders either.

Really annoying and frankly a deal breaker for using this software going forward without a satisfactory solution.

Running Linux Mint on a Lenovo ThinkpadT490 Many thanks

Please Please Please advise how to modify settings to stop copying emails to "All Mail" folder. There are nearly 14K emails in that folder, and it's killing my capacity, I'm getting warnings, etc. Yes, I'm using Gmail.

Yes, I have unsubcribed from it, starting from my account name → Subscribe → unchecked [Gmail] All Mail. To no avail...

Of course, I do not want to delete mails I have saved in my hundreds of other folders. My mail goes back 25+ years, and I want to keep those archives.

Thank you Thank you Thank you!

This just started 4 or 5 days ago ( 2026.1.23 ish). I did not update TB nor make any changes to the account in question (that I'm aware of). The errors show up every few minutes, with a 'beep' sound and notification pop-up showing up each time - is very annoying.

I was running v145 when it started. I saw there was an update to 147 and installed that; same issue. I restarted TB into Troubleshooting mode and am still getting the error.

This is running on MacOS 15.7.3. Hardware is MacMini (2024) with Apple M4 chip.

Generally I still seem able to received & send emails.

I opened Activity Manager and Error Console. Error console doesn't seem to have much (using 'Multiprocess', with Errors, Warnings, Logs, Debug enabled). Activity manager shows things such as:

<my account name>

   Connection to server outlook.office365.com was interrupted.    09:49
   Failed to connect to server outlook.office365.com.    09:52
   Authentication failure while connecting to server outlook.office365.com.    09:58
   Authentication failure while connecting to server outlook.office365.com.    10:03
   Connection to server outlook.office365.com was interrupted.    10:10
   Connection to server outlook.office365.com was interrupted.    10:14
   Connection to server outlook.office365.com was interrupted.    10:20

There was an error or log entry that I was able to find a few days ago that made me think it was Calendar related, but now I'm not finding that message.

One of my cabinet folders is missing emails and a sub-folder that exist in my Fastmail account. These missing items are on both the windows and macOS versions I have installed. Please advise on how to to repair. Thanks.

Maybe a red herring: I was in the middle of doing a Documents folder backup when I decided to open Thunderbird for some reason. Got an Unable to Load Profile type of message. And my attempts at a fix seem to just send me further down a rabbit hole. I started out by renaming my profile.ini file, but I really didn't know what the heck I was doing and possibly caused more harm than good. Then I tried to find my profile file/folder itself, using the Thunderbird > Troubleshooting > Profile Folder path and doing an import from inside TBird but that ended up with various problems such as drilling down to the profile folder from within TBird but then when I clicked Select Folder in Thunderbird, that didn't trigger any sort of import.

I also spent a good deal of time trying to find my AppData folder, finally being able to view it (a hidden folder, apparently), and saw several recently-dated profile types of folders, but again, I couldn't manage to "hook up" any of those folder/files from starting inside TBird and selecting Import... I ended up just stuck inside a folder, not triggering any Importing activity.

Finally I found a profile folder (5yed...) at a higher level on my PC than inside that long AppData Roaming Thunderbird path. THIS profile was inside: D:\DOCS\Thunderbird\Profiles

Now THAT folder I managed to get an Import to trigger. But the result was an Error Message telling me to go find my Error Console. Can you please see the attached Error Code display screengrab and tell me there's hope that this was at least the right file but just poor results that I can fix somehow???

The following is my copy/paste of the text I see in the Error Console display that's in my screengrab after trying to import the above 5yed... profile, in case it helps you see it better:

1765349209272 addons.xpi WARN Checking C:\Program Files (x86)\Mozilla Thunderbird\distribution\extensions for addons WebGL context was lost. 2 Troubleshoot.sys.mjs:727:17 Content-Security-Policy: This site (https://www.mozilla.org) has a Report-Only policy without a report-uri directive nor a report-to directive. CSP will not block and cannot report violations of this policy. thunderbird downloadable font: Glyph bbox was incorrect (glyph ids 441 459 695) (font-family: "Open Sans" style:normal weight:700 stretch:100 src index:0) source: https://updates.thunderbird.net/media/fonts/opensans-bold.woff2 downloadable font: Glyph bbox was incorrect (glyph ids 459) (font-family: "Open Sans" style:normal weight:400 stretch:100 src index:0) source: https://updates.thunderbird.net/media/fonts/opensans-regular.woff2 Uncaught (in promise) NS_ERROR_FILE_NOT_FOUND: Component returned failure code: 0x80520012 (NS_ERROR_FILE_NOT_FOUND) [nsIFile.copyTo]

   _recursivelyCopyMsgFolder resource:///modules/ThunderbirdProfileImporter.sys.mjs:652
   _recursivelyCopyMsgFolder resource:///modules/ThunderbirdProfileImporter.sys.mjs:661
   _mergeLocalFolders resource:///modules/ThunderbirdProfileImporter.sys.mjs:634
   _importServersAndAccounts resource:///modules/ThunderbirdProfileImporter.sys.mjs:243

ThunderbirdProfileImporter.sys.mjs:652

Also attached below are also:

• a screengrab of a set of profiles I found, but when I drilled down to them from within TBird's Import selections and clicked Select Folder, as far as I got was an open folder, or something like that.
• Thunderbird's Troubleshooting Info "Profile Folder" path.
• Message telling me to see the Error Console. The message appeared right after I tried importing the profile that's stated in TBird's Troubleshooting Info "Profile Folder" path.

Here's the copy/paste of the Error Console message display after my try at importing the profile that is in the path that TBird's Troubleshooting Info page "Profile Folder" states (maybe it's the same as my 5yed...profile import try's Error Console display, dunno:

1765353636640 addons.xpi WARN Checking C:\Program Files (x86)\Mozilla Thunderbird\distribution\extensions for addons Content-Security-Policy: This site (https://www.mozilla.org) has a Report-Only policy without a report-uri directive nor a report-to directive. CSP will not block and cannot report violations of this policy. thunderbird WebGL context was lost. 2 Troubleshoot.sys.mjs:727:17 downloadable font: Glyph bbox was incorrect (glyph ids 441 459 695) (font-family: "Open Sans" style:normal weight:700 stretch:100 src index:0) source: https://updates.thunderbird.net/media/fonts/opensans-bold.woff2 downloadable font: Glyph bbox was incorrect (glyph ids 459) (font-family: "Open Sans" style:normal weight:400 stretch:100 src index:0) source: https://updates.thunderbird.net/media/fonts/opensans-regular.woff2 Uncaught (in promise) NS_ERROR_FILE_NOT_FOUND: Component returned failure code: 0x80520012 (NS_ERROR_FILE_NOT_FOUND) [nsIFile.copyTo]

   _recursivelyCopyMsgFolder resource:///modules/ThunderbirdProfileImporter.sys.mjs:652
   _recursivelyCopyMsgFolder resource:///modules/ThunderbirdProfileImporter.sys.mjs:661
   _mergeLocalFolders resource:///modules/ThunderbirdProfileImporter.sys.mjs:634
   _importServersAndAccounts resource:///modules/ThunderbirdProfileImporter.sys.mjs:243

ThunderbirdProfileImporter.sys.mjs:652

Thanks for any help in getting through this.

I have got two e-mail by Thunderbird : d.nadal@orange => OK but danielle.nadal@kohinos.net NO connection Thunderbird said : connection time exceeded'. What to do?

My husband and I use the same internet provider activ8 and access it through Thunderbird. I have a new computer. Received a configuration code from Activ8 and I can receive emails but not send them. Get the message PEER USING UNSUPPORTED VERSION OF SECURITY PROTOCOL. THE CONFIGURATION TO MAIL.ACTIV8.NET.AU MUST BE CORRECTED. How do I do that? Activ8 says they can't help.

WHY IS THUNDERBIRD TELLING ME THAT MY G MAIL ACCOUNT WILL BE ACCESSED BY IT AND CHANCE OR DELETE SAID ACCOUNT? I'M TRYING TO USE THUNDERBIRD IN LINUX ZORIN 18 OS IN MY LAPTOP. i NEED A COMPLETE INDEPENDENT EMAIL SERVICE WITHOUT THE connections TO MICROSHIT, GOOGLE, ETC. IF THIS IS NOT POSSIBLE I WILL DELETE THUNDERBIRD FROM LINUX THANK YOU REGARDS ALFONSO P.S. IT IS NOT FOR THIS COMPUTER. I'M JUST USING THIS COMPUTER TO COMMUNICATE WITH MOZILLA

My computer suddenly started the above error message for multiple programs. The local computer shop was able to sort out what appeared to be the root cause and that recovered some things but I still needed to reinstall a number of programs.

The program I am terrified of reinstalling is Thunderbird. All my emails on five email accounts since 2011 are stored in TB and I naturally do not want to lose any of them.

The major problems are the computer is running Win7 Enterprise and I am 82 years old so I am prone to needing things spelt out in greater detail than many others.

Can anyone provide a way to reset the program permissions (preferable) or identify the best way to reinstall and still access all my historic emails?

Thank you

Continuation of my prior post: https://support.mozilla.org/en-US/questions/1516342

Thunderbird has a routine problem with being unable to log into various mail servers. I have four accounts and they all seem to share this problem.

Most recent update: I've tested this in Windows Safe Mode, and the problem has not appeared. Since I can't do any useful work in Safe Mode, it's hard to give it a thorough test, but so far so good. Also, I have removed AVG antivirus because it was redundant. I have seen no improvement since it was removed.

Can this problem be resolved?

I am running Thunderbird 147.0.1 (64-bit) on Windows 11 Pro 25H2. I have Thunderbird set up with two email accounts -- gmail and outlook.com (an old msn.com address). Approximately every 10-14 days the msn.com account encounters an error with the message "Command Error 12." When this happens, Thunderbird immediately drops all the local email folders for the msn.com account, and attempts to redownload all email and folders associated with the account. The msn.com account in question is configured for IMAP:

server name: outlook.office365.com Port:993 Connection Security: SSL/TLS Authentication Method: OAuth2

The expected behavior here would be for Thunderbird to display a connectivity error message but retain all local email on my laptop. However, this specific connectivity issue is dropping all locally stored email. I also noticed that the mail columns get reset to default. It appears this issue is causing Thunderbird to delete not just the email but some of the account configs as well.

At present, I do not have a screenshot showing the command error 12 message. I will try to take a screenshot the next time the issue occurs. What is not clear is whether this is an account setup issue or a bug in Thunderbird. Any advice would be appreciated. Thanks.

I can't login to one of my email addresses. It says login to server with username failed. I tried all of the suggestions (using a pop server for example) and none of them seem to work. Please help.

Folder name: BOGUS AI PRAISE-MKTING-BOOK CLUB BULLSHIT I had been adding emailed marketing messages that I knew were fake into this folder for about two weeks. This morning, after a Windows 11 Update, when I tried to add another such message to that folder, the entire file folder was missing. I tried everything I could think of, including looking for help online, to no avail. This folder contained around 500 emails, over 200 of which I hadn't even opened.

I'm trying to find the proper way to revert back to the default location for local mail message storage in TB (ver 140.7.1 esr).

Years ago I set my local message storage to a storage drive on my Win10 PC. I now want to move all of TB to a new Win11 PC but realize I have thing in 2 places - messages on my storage drive and everything else of TB in the default C: drive location.

If I simply change the Message Storage Local Directory back to the default path - will it move my current/old messages to the default location or do I have to manually move things (first or after?)?

I have many years and about 13Gb of email messages that I want to ensure I keep.

TIA