10/14/2020. I can not delete emails. When I try I get the message 'The current operation on 'Inbox' did not succeed. The current mail server for account mhart@jetbroadband.com responded: UID COPY Destination folder does not exist.' I tried the suggestion of deleting the trash and trash.msf folders and restarting Thunderbird; the new Trash folders were automatically generated but the problem continues.