Apple Mail Folder [the one containing V8] is MISSING from Big Sur
Running Big Sur 11.2.3 on MacBook Pro M1 2020.
The missing folder was present 3 days ago, I thought no worries it is on Time Machine.
No such luck, however far back searched, it does not exist.
IIRC Time Machine was used to Restore the main Mail Folder in January 2021.
On my Mac Pro 5.1 2012 running High Sierra 10.13.6 the equivalent Folder is also missing.
Mail is functional in that it can Receive and Send messages.
All relevant Mailboxes have the appropriate content.
This seems to suggest that the main Mail Folder has not been destroyed but 'displaced'?
First thoughts on recovery were to Reinstall the macOS, but I also have no wish to make things even worse and would welcome advice on how to proceed.
Thanks in advance for help offered.
MacBook Pro