Configure email account on Exchange 2013 or older on 365 Outlook
From within Outlook choose 'File' - 'Account settings' Select 'New'
Type the email address, choose 'Advanced options' and check the box 'Let me Set up my account manually' and 'Connect'
It will then take a while but eventually present 'Advanced setup.
Choose 'Exchange 2013 or earlier' again it will then take a while.
You should now be able to enter the custom settings