Microsoft is retiring Active Directory Rights Management Service (AD RMS) support in Exchange Online as of February 28, 2021. Moving forward, we recommend the utilization of Azure Rights Management Service (Azure RMS).
Timing: February 28, 2021
Action: review and assess impact for your organization
How this will affect your organization:
Exchange Online includes Information Rights Management (IRM) that provides online and offline protection of email messages and attachments. Although Exchange Online uses Azure Rights Management Service (Azure RMS) by default, your organization may have configured Exchange Online to use on-premises Active Directory Rights Management Service (AD RMS). AD RMS support in Exchange Online is retiring, and will be fully replaced with Azure RMS.
What you need to do to prepare:
If your organization is already using Azure RMS to encrypt email in Exchange Online, there is nothing for you to do.
Otherwise, follow the these steps to migrate to Azure RMS
If your organization has already set up Azure RMS, you can enable the service in Exchange Online by running the following Exchange Online PowerShell cmdlet:Set-IrmConfiguration -AzureRMSLicensingEnabled $true