Web: Office 365 (O365) Email Settings
Basic Information
The Office 365 (O365) Email Settings system relies on the organization having and utilizing two things:
- An Azure Active Directory (AAD) system hosted on Microsoft Office 365 system; and,
- An Exchange Email system utilizing and connected to that AAD system.
Setup
In Azure Active Directory admin center, click on "App registrations". 
Choose "New registration". 