Did you check the accounts online?

David - thank you for your attention

Yes, the emails are gone there as well ( all three accounts). All IMAP

It is as if I deleted all the emails (in three different email accounts, two gmail and one fastmail). I can make mistakes, of course, but not the same mistake on all three accounts

I encourage you to check with email providers to see if they have logs on recent mail arrivals. Thunderbird doesn't have facility to delete an entire account at once. Very puzzling. I am at a complete loss on how three accounts should simultaneously be empty,

OK, thank you -- just weird (I feel like I have been hacked - but not all three accounts at same time - and my laptop has been with me...

One final question -- Can I see when a file has been deleted and moved to trash. If I knew that, I could do a manual recovery?

David, thank you again

sigh

You might check tools>developer tools>error console There may be something useful there.