Hello, In my work email account (Zimbra instance), very regularly new emails keep reappearing as unread even after they are marked as read. If I restart Thunderbird, or if I go offline then online again the problem is solved; however, I would like a more definitive solution. When the problem occurs, in the console I can see "The current operation on 'Inbox' did not succeed. The mail server for account X responded: mailbox selected READ-ONLY.". I tried solution suggest at https://support.mozilla.org/en-US/questions/1276757, i.e., setting `mail.server.default.send_client_info` to `false`, but it did not work. Any other suggestion?