I have received a message from Dropa, for which I thank him/her but which, unfortunately, I do not understand. (I also do not understand why this message does not appear under "My Questions" in my Profile.) Tom

right click the folder, select properties and then the repair button.

Matt, I appreciate your help but I'm afraid your suggestion did not solve the problem. I've run through my Inbox for 2023 and these two messages do not come to light. As this advisory only appeared a few days ago, I believe it is a defect and the two messages do not exist. How to get rid of it? Tom

Is there a sub folder? Collapsed sub folders have their unread mail count shown in the parent folder. Something beside the folder name? Like > which changes to a ∨ when you click it to show the sub folder.

That's it -- thanks very much, Matt. The two unread messages were buried in two unrelated "subfolders" These "subfolders" seem to be a new wrinkle in Thunderbird and frankly I don't see what purpose they serve. You get an email...you reply to it in the normal way...and the response to that reply, instead of appearing as a normal-looking, separate email in bold, is hidden under the original email. The only clue to this hidden message is that it is a "threaded message". Why add these complexities? Tom

That's it -- thanks very much, Matt. The two unread messages were buried in two unrelated "subfolders" These "subfolders" seem to be a new wrinkle in Thunderbird and frankly I don't see what purpose they serve. You get an email...you reply to it in the normal way...and the response to that reply, instead of appearing as a normal-looking, separate email in bold, is hidden under the original email. The only clue to this hidden message is that it is a "threaded message". Why add these complexities? Tom

I'm not so sure you are talking about sub-folders...it sounds like you have : View > Sort by > 'Threaded'

The developers have caused much confusion by deciding to set certain preferences by default.

Do this: Select Inbox for account

• View > Sort by > select 'Unthreaded'

Then apply that view to all other folders in the account: Right click on column headers and select 'Apply current view to' > hover over 'Folder and it's children' > hover over mail account name to see list and this time click on mail account name.

It will say apply to all folders in account and you say 'yes'

If you want to set up auto set as unthreaded on any new folder then do this:

• Settings > General
• Scroll to bottom
• click on 'Config Editor' button - It opens in a new tab
• In search type: default_view
• You will see this line: mailnews.default_view_flags - It will have a numerical value of 1
• click on the 'pencil' icon on the right to allow an edit.
• Remove the number 1 and type in a zero 0
• click on the 'tick' icon to save your settings.

You will now have: mailnews.default_view_flags - It will have a numerical value of 0 This will now mean any new folders you create, they will not have threading by default. Note images below as a guide.

Tried everything here, still shows 2 messages in inbox, but only one unread.

It looks like a pop mail account. It looks like you have not enabled the Quick Filter, so it should not be effecting any filtering from that point of view.

Have you checked to see if any filters are operating or maybe there is an email which has got marked as ignored?

'View' > 'Threads' > select 'All' If you do not see any change then also select: View > Threads > select : 'Ignored Threads'

if you logon to webmail account via a browser do you see the missing email in the Inbox ?

I did a repair on the mailbox and it showed up. A few other things previously deleted as well, but that was the solution.