is the account accessed from another device like a phone, tablet or other PC?

Yes, it is. My Android phone's email app is sync'ed with my Gmail account, but only used on rare occasions. Still IMAP is supposed to keep all the devices up-to-date.

astroman133 said

Yes, it is. My Android phone's email app is sync'ed with my Gmail account, but only used on rare occasions. Still IMAP is supposed to keep all the devices up-to-date.

try turning the phone off and see if newly arrived email stop being "read". I have seen others where the phone uses POP and it marks all messages read on google as they are downloaded.

I already made that change to see if my symptoms change. But my problem is not that msgs are being marked as "read". It is the opposite...They keep getting set to "unread" after I have read them. I often must "read" them 4 or 5 times.

Have you ever tried the simple step of right-clicking the folder, Properties, Repair Folder? That will rebuild the msf index file, but a complete rebuild of the Inbox is done by deleting the Inbox mbox file and Inbox.msf from the profile folder, and having a new Inbox created when you restart TB:

http://kb.mozillazine.org/Compacting_folders#Real_fix

If none of that helps, I would create a new profile, add the account, and test the read/unread status. Help/Troubleshooting, about:profiles, to create a new profile; the current one is unaffected.

I tried both of those suggestions already. I created a new profile on this PC in mid-2019, when it was new and I first set it up. I repaired the folders a few times but it had no effect.

Based on an initial suggestion, I disabled synchronization between my gmail account and my phone. This did not solve my issue. I still have emails that revert to unread status even after I have read them 4 or 5 times. Right now the best solution is to right-click the folder name under my gmail account and mark the entire folder as read.

This problem is still occurring. No other suggestions? Is this a bug?

astroman133 said

This problem is still occurring. No other suggestions? Is this a bug?

I you think you have the one in 10 million system, then yes it could be a bug. I see lots of folks about read/unread status, but it always comes back to a phone table or other device accessing the account as well.

Have you tried

• Restart Thunderbird with add-ons disabled (Thunderbird Safe Mode). On the Help menu, click on "Restart with Add-ons Disabled". If Thunderbird works like normal, there is an Add-on or Theme interfering with normal operations. You will need to re-enable add-ons one at a time until you locate the offender.
• Restart the operating system in safe mode with Networking. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, OSX

If safe mode for the operating system fixes the issue, there's other software in your computer that's causing problems. Possibilities include but not limited to: AV scanning, virus/malware, background downloads such as program updates.

Thanks for your suggestions. I do not have any add-on's installed, but will still try your Safe Mode approach.

BTW, my primary Win10 desktop system which has this issue replaced, about 9 months ago a Win 7 desktop system that had the same issue.

If other software is causing a conflict with Thunderbird, then it is most likely background services/processes. Most of them are part of Windows, or what I call "update stubs" for other apps that perhaps run only rarely.

I am not sure where to go if the problem does not occur in Safe Mode.

Thanks!

I would look at the ubiquitous security software. Especially anti virus, anti scan and anti spam tools. Most of them cause more issues than they fix.