outlook 365 accounts

I am trying to set up an Exchange account in Outlook 365 on a pc running Windows 10 Pro. The setup process in Outlook 365 does not allow me to specify the Exchange serve address myself, and so the setup fails because Outlook can't find the server details automatically. This computer is not on the work domain so this is an "off network" setup. However I tried to set the account up with the VPN connected but it still wouldn't work. Any ideas?