Using classic Outlook for Windows in business environments
I also have the problem that I can read my email with the new Outlook for a while, but then suddenly appears "Acess Denied". After that I can try and try, but won't be able to login for quite some time.
It is about time that I switch over to Mozilla Thunderbird on this computer as well, as it works well on my other PC. (And on Linux as well as iOS.)