We have an SBS 2011 server which is working well. We have just upgraded one of our office Windows 10 laptops to MS Office 365. The problem we have is that when Outlook opens it it pulls down all the new emails etc and is connected to Exchange. As soon as it finishes this updating process a windows credentials box appears and asks you to put in the password. In the username it has the correct email address but shouldn't this be the users username not email. Either way if you put in the password it accept this and connects again and then after a small random time period it does the same thing. Its like it forgets the credentials.
We have tried deleting the credentials in credential manager but same thing
Any help would be appreciated?