Exchange Server AD FS Modern Authentication: Expanded Outlook client support

This update is a massive win for pure on-premises environments. For a long time, managing strict security policies or MFA requirements on mobile devices without relying on Exchange Online or Hybrid Modern Authentication (HMA) felt like an uphill battle. Bringing native OAuth and AD FS support directly to Outlook for iOS and Android removes one of the last major roadblocks for organizations locked into an on-premises footprint due to regulatory or architectural constraints.

It also ties things together nicely alongside the existing desktop and native mobile mail client support, finally giving end-users a seamless, uniform login experience across all their devices instead of having to work around legacy authentication limitations or third-party client workarounds.