When I open Thunderbird, I will receive the following message regarding my outlook account --> "The current operation on 'Inbox' did not succeed. The mail server for account xxxx@outlook.com responded: Namespace Command is not permitted in current state (NotAuthenticatedServerError)" The strange thing is, I will close Thunderbird and reopen it, and then it will work. But if I close and reopen again, it will give me the message. It happened every other time I use Thunderbird. I would really appreciate the help