Your message is confusing to me. You indicate missing emails, but you also state that all messages are on the IMAP server. If all are on the IMAP server, then they are accessible through Thunderbird. There are no special settings to bring in just a range of messages.

David,

   Thanks. The situation is confusing to me also. I do not understand why, when I can see the messages on the server using a web client, Thunderbird would not pull them down. I have my system set to leave messages on the server. As I indicated in my related message, I followed some instructions I found on the web (url in other message). They seemed to have resolved this issue. When I restarted Thunderbird it pulled down missing messages. However, I am still in a situation where I cannot create folders under my iMap acconts. I noticed that under my POP account, if I right click to create a sub-folder i get a choice "new subfolder". However, under my iMap accounts the right click yeilds "new folder". New sub-folder works but new folder does not.

Guerney

Possibly there are restrictions from your email provider. You might check there.

Person who asked question posted all this information as a new question . I've copy pasted all info into this original question.

gdhhunt 7/27/22, 6:47 PM

I need to give you more information so that (if you have time) you can help me debug the problem. We are running Thunderbird 91.11.0 (64-bit). We have been using Thunderbird for many years. Our machine is: Device name Black-Walnut_22 Processor AMD Ryzen 9 3900X 12-Core Processor 3.79 GHz Installed RAM 31.9 GB Device ID B1922514-B651-4EA7-8D97-47D2CD3F8951 Product ID 00330-80008-96792-AA363 System type 64-bit operating system, x64-based processor Pen and touch No pen or touch input is available for this display

We are running:

Edition Windows 11 Pro Version 21H2 Installed on ‎1/‎17/‎2022 OS build 22000.795 Experience Windows Feature Experience Pack 1000.22000.795.0 As I said in my previous e-mail Thunderbird suspended operations for about 2 days. When it resumed....

three of our proton mail account no longer had send, junk, archive, draft or trash folder. Further, I can no longer create sub-folders under any e-mail account. The Thunderbird client has five e-mail addresses three are proton mail (iMap) and two are verizon.net (POP). When the client "suspended operations" only the iMap email accounts were affected.

I looked around for instructions on how to address this issue and found the following: https://recoverit.wondershare.com/email-tips/fix-thunderbird-folder-or-emails-missing.html Neither methods 1 or 2 worked. (I tried these instructions because I had an issue a few years ago that similar instructions, possibly from Mozilla, fixed) I noticed as I was poking around that there is a new version of Thunderbird 102.x.x.... . Other things I read implied that sometimes Thunderbird has to be reinstalled to fix issues. The simplest thing is to reinstall the version we are on. I noticed that there is no automatic migration to the newer version.

If anyone has any ideas, I am interested.

Thanks, Guerney

Those instructions help to fix folders that are missing emails or have blank emails or emails with wrong header - not matching contents. You do not say you have that problem, so that fix is not going to help in your case.

So basically: Windows 11 64 bit Thunderbird 91.11.0 (64-bit) Thunderbird suspended operations for about 2 days. Then resumed....

you have 3 proton mail imap accounts that have missing folders, do not send or receive mail and you have no ability to add folders etc etc. They are not connecting to server - something is blocking it. The two verizon pop accounts work perfectly ok.

Did you buy the computer with Windows 11 pre installed ? OR Did you recently select to upgrade from Windows 10 to Windows 11 ?

This sounds like you upgraded from Windows 10 to Windows 11 Then Microsoft in it's wisdom messed up access for your email client app - aka Thunderbird.

Thunderbird does not suspend activity unless you chose not to start Thunderbird. Something was blocking it and Microsoft is probably the culprit.

Have you got the Smart Control operating on your version of Windows 11 Pro? https://www.microsoft.com/security/blog/2022/04/05/new-security-features-for-windows-11-will-help-protect-hybrid-work/

Have you reset Thunderbird as the default mail client? Have you check and set up the Firewall so it has Thunderbird as an allowed program in it's list? Thunderbird must be listed as an allowed program.

re : read implied that sometimes Thunderbird has to be reinstalled to fix issues. The simplest thing is to reinstall the version we are on.

That is only useful if the installation did not fully complete - it rarely fixes any issues and is complete waste of time in 99% of cases. You have already stated that the verizon accounts work ok , so clearly there is no problem with Thunderbird per se.

However, as you do have imap mail accounts, I would remove one of them via the Account Settings > Account Actions Restart Thunderbird and then recreate - 'New' > 'Existing Mail Account' for that email address and set up as an imap mail account.

Dear Toad-Hall

    Thanks, I will walk through all of your points and confirm or correct as appropriate. As you conjectures, I migrated from Windows 10 to windows 11 (I upgraded a machine I had previously built).  FYI, I was not sure it was a Thunderbird problem. The reason I asked here is that prior to the suspension of activity, no folders were missing and everything was working properly.  After I check the background settings you suggested, if that does not fix the issue I will try deleting and recreating a proton mail account. On my wife's laptop I also migrated from Window 10 to windows 11 and there are no issues. The difference is that Thunderbird was installed for the first time after the migration. On this computer, the windows migration tool would not work because of the way I have it configured (some security features I use that Microsoft was not expecting) consequently, I had to install Windows 11 from scratch (virgin disk), install Thunderbird, and migrate my e-mail configuration. Note that the migration at the beginning of the year.

Guerney

Dear Toad-Hall,

    As best as I can tell smart control is not running on my system. That appears to be for "managed systems" which this computer is not. Thunderbird was not set as the default mail client, it now is. Thunderbird was not in the list of apps allowed through the firewall. However, the proton mail bridge is on the list.  This is required in order to connect to protonmail. I added Thunderbird to the list.
  When talking to my wife, I found out that Thunderbird "suspended" on her laptop also. This indicates more clearly that it is a Windows issue. Thunderbird resumed on its own, but has not recovered the missing e-mails. However, on her laptop, sub-folders can be created. Also, her laptop never lost the sent mail and drafts folders. Interesting ...
    The only thing I did not say about my upgrade is that I went from and Intel CPU to an AMD cpu at the same time I moved from Windows 10 to Windows 11. In theory, that should not make a difference.
   Exiting Thunderbird and restarting after configuration changes caused the sent folders and trash folders to reappear.  Unfortunately, I still cannot create sub-folders.  
    

Guerney

Between Toad-Hills suggestions and rebooting the machine (it is normally rebooted at least once per day) and discovering possible user error. The problem appears to be fixed on this machine. I have a good idea of how to fix the lap top, so I will handle that separately. Since it ran for approximately 7 months without error I have no idea what caused the suspension, unless it was related to a recent windows update. I concur with Toad-Hall that this was not a Thunderbird error.

Thanks to all, Guerney