Microsoft Extends On-Premises Authentication Support to Outlook Mobile Apps

Microsoft has expanded its Exchange Server AD FS Modern Authentication support to include Outlook for iOS and Android apps, providing a more consistent authentication experience across Microsoft's Outlook apps for organizations running supported on-premises Exchange deployments.

This feature was previously only available for the Outlook desktop apps on Windows and Mac, as well as the native Mail apps on iOS and macOS.

However, this expansion comes with an important limitation: AD FS Modern Authentication is intended only for organizations running Exchange entirely on-premises without Microsoft Entra ID or a hybrid Exchange configuration. Companies already operating in a hybrid environment are still expected to use Hybrid Modern Authentication (HMA) with Microsoft Entra ID instead.

Microsoft has also updated its deployment documentation to consolidate client requirements and configuration steps, making it easier for IT administrators to validate and deploy this feature.