1. Find & open your Thunderbird Profile folder:

Select Help: Troubleshooting Information from the Thunderbird menu (either from the menu button , on the top right, or the normal menu at the top of the window.)

Under "Application Basics", beside "Profile Folder", click the "Show Profile" button.  This will open a window showing the contents of your Thunderbird Profile folder.

2. Quit Thunderbird, but keep that window open showing your Thunderbird Profile folder.

3. Delete "global-messages-db.sqlite" and "panacea.dat" from the profile folder.

4. Start Thunderbird. Select the account on the left, then from the menu bar or the "three bar" menu button on the top right, select File: Compact Folders.

ty for the suggestions. i tried your protocol several times, but alas- nothing has changed. cordially, emlsr

the unread button filter the view to only unread mail. try hitting it again to turn of the filtering.

thanks matt, but mea culpa. the fact is the messages disappear no matter which button i hit- be it tag, date or anything else.

emlsr

Just to confirm, are you looking at the Quick Filter bar?

In my screenshot, you will see that one of the items in the quick filter bar is selected, so now only unread messages are seen, and read messages are hidden.

By the way, "Mea culpa" means, "My fault!". It is an acknowledgment of one's responsibility for a fault or error.

While you may be at fault, we haven't determined that yet!