Microsoft is currently addressing an ongoing outage that has impacted access to its Outlook email and other Microsoft 365 services, now entering its second day. The disruption originated from a misconfiguration within the core authentication system used by multiple Microsoft 365 services, including Exchange Online. This issue led to email delays, failures, authentication problems, and degraded performance in several services such as SharePoint, Teams, Copilot, and security solutions like Defender XDR.

The company reported significant progress on Monday after investigating recent changes that may have caused the problem and implementing targeted mitigation strategies. As these fixes were deployed, Outlook users began to notice gradual recovery in mail flow, although search functionality within the platform remained impaired into Monday night. Microsoft confirmed that by early Tuesday morning, search capabilities showed signs of improvement.

Despite these advancements, Microsoft has not yet declared the issue fully resolved. Their status updates indicated ongoing efforts to mitigate the remaining effects on affected infrastructure, with telemetry data suggesting positive trends. The company emphasized it is now in an extended monitoring phase to ensure that service stability is fully restored for all users.

This incident highlights the complexities in maintaining large-scale cloud services and the ripple effects a core authentication failure can have across a suite of interconnected applications. Organizations that rely heavily on Microsoft 365 for communication, collaboration, and security have been closely watching the situation as Microsoft works to restore full operational status.