Hi there. I've been using Outlook for my principal email address (ctomkinson@ttis.net) for years now, via Firefox. Suddenly today I receive an error message, when attempting to log in to my Outlook mailbox: please see the screenshot I've attached. I do not understand why there is any problem? How can it be suddenly that the error message appears User Has Not Mailbox And Account Not Assigned? I have more than 25,000 mails in my inbox, upon which I often draw for old addresses and searches. There is no possible way that I "have not mailbox"! This issue is confined to Firefox. I can access the email account via Chrome just fine. Any help is much appreciated!