Does the following help?

Menu icon > Help > More Troubleshooting information Under 'Application Basics' half way - Profile Folders - click on 'Open Folder' A new window opens showing contents of profile folder. Exit Thunderbird now - this is important. Locate the 'virtualFolders.dat' file and delete it. Click on 'Mail' folder to see contents. Delete the 'smart mailboxes' folder Start Thunderbird Allow any mail to download Set 'View' > 'Folders' > 'Unified'

thanks. -sorted ( I think) It creates a new view in the LH column that I can move up , but there are still stray folder from one of my email addresses appearing between the inboxes

there are still stray folder from one of my email addresses appearing between the inboxes

For this issue,

• Install debugging extension - download https://addons.thunderbird.net/en-US/thunderbird/addon/unified-folders-debugging/ and do
• If you do not see the "Unified Folders" heading in the folder pane, then click on horizontal dots "..." next to "New messages", click "Folder Modes", enable an additional folder mode to force the "Unified Folders" heading to appear
• click on vertical dots ⋮ next in the "Unified Folders" heading
• click Debugging Info > click Copy to Clipboard and save the clipboard somewhere
• Click Close.
• Click "Reset Unified Folders" in the Unified Folders heading. (Do this last)

Does that help?