Hi Paul,
Could I collect some information to troubleshoot this issue?
1. How many users are there in your Office 365 organization? Do other users encounter the same issue?
2. About this error “Your organization is marked for removal”, I suggest you refer to the steps to check this: Sign in to your Office 365 portal, and then click licensing on the left menu bar. What is the status of your current subscription?
3. Moreover, have you ever configured your Office 365 account on any mail client, such as Outlook client, mobile? If so, can you access your account from the client?
Thanks,
Young Yang