Add Authorised Domain in Office 365

The authorised domains set in the local Exchange service do not get synchronised into Office 365, so they need to be added independently. Open a powershell window and start a session to Office 365 – you will also need to connect to the MsolService (see Connect to Exchange Online). Run the following command to add a domain –

New-MsolDomain -Name new.domain -TenantId eaab77ea-b4a5-49e3-a1e8-d6dd23a1f286 -Authentication federated

Note: The TenantId can be found in the Azure Active Directory admin centre under properties