Setting up the Microsoft 365 tenant

The following configuration is done in the Microsoft 365 tenant. You will need to log into the tenant as a full administrator.

1. Launch the Microsoft 365 admin center. To get there, go to admin.microsoft.com or, if you're already signed in, select the app launcher, and choose Admin.
2. Perform the steps of section Adding a new / custom email domain.
3. Perform the steps of section Creating the EWS Default User.
4. Perform the steps of section Getting DNS details from your Microsoft 365 tenant.
5. Perform the steps of section Setting up Mailflow Connector.
6. Perform the steps of section Registering a new app in Azure Active Directory.
7. Perform the steps of section Using User Context for OOS Document Editing.
8. Perform the steps of section Disabling TNEF globally in Exchange Online (recommended).