Microsoft reported seeing positive results for server stability and increased capacity on Friday morning as it works to resolve a global service degradation affecting both business and consumer products that happened the previous day.
According to Microsoft’s official service health portal (status.cloud.microsoft), engineers applied a patch to an upstream authentication and routing configuration component across a portion of its infrastructure and are expanding the update to servers supporting active regions coming online. Engineering teams are pursuing a controlled recovery by cycling affected infrastructure through traffic drain, restart, remediation, and a staged return-to-service. Network and traffic-management actions remain underway, and teams are prioritizing backlog and queue health to protect delayed mail during recovery. The company stated on its status page that it is unaware of any malicious activity causing the incident and will publish a Post-Incident Report detailing the root cause once the issue is resolved.
What Is Impacted
According to Microsoft’s official service advisories (tracked under incident IDs EX1550543 and MO1550821), network monitoring firm Cisco ThousandEyes, and reporting from SecurityWeek and The Guardian, the disruption affected:
- Exchange Online & Outlook: Users across desktop, web, and mobile clients encountered connection timeouts, server errors, and an inability to access mailboxes or send and receive emails.
- Microsoft 365 Connected Features: Features within Microsoft Teams, Microsoft Copilot, and other Microsoft 365 applications that depend on interacting with Exchange Online were disrupted. According to Microsoft and The Guardian, core functions independent of Exchange (such as Teams chats and meetings) remained functional or recovered earlier.
- Third-Party Integrations & Public Agencies: According to The Guardian and status pages from OpenAI and Anthropic, third-party AI connectors relying on Microsoft mail and calendar integrations experienced failures, while government agencies, schools, and public services in the U.S., U.K., Japan, and Australia reported operational disruptions.
- Microsoft 365 Admin Center: Some administrators were unable to access the internal service health dashboard, prompting Microsoft to direct users to its public status page.
Early Friday morning, Microsoft deployed an upstream authentication and routing patch alongside traffic optimizations, resulting in improved server stability while active regions remain under monitoring for ongoing service degradation. Those measures followed a prolonged effort Thursday night in which restarted servers repeatedly became unresponsive again once live user traffic returned, leading engineers to isolate infrastructure, pause deployments, and restrict certain types of traffic. The incident began Thursday afternoon with Exchange Online connectivity errors in the Americas before expanding globally, which Microsoft traced to servers dropping offline after failing automated health checks.
