Microsoft 365 Outage Disrupts Outlook, Teams Globally

A widespread outage at Microsoft on Thursday disrupted Outlook, Teams, and several other Microsoft 365 applications for thousands of users across the globe. Users experienced difficulties accessing emails, work files, and essential productivity tools for over 10 hours. The disruption also impacted third-party platforms such as OpenAI and Anthropic, which faced issues with their Microsoft 365 connectors.

Reports on Downdetector indicated approximately 38,000 outage reports globally, with more than 4,500 related to Microsoft Teams. Microsoft initially attributed the problem to elevated load on its infrastructure, but later clarified that it was due to several servers unexpectedly becoming unavailable, causing strain on the remaining infrastructure.

Microsoft has been providing regular updates on its progress to restore services through its X platform. The company had initially tested a configuration change to address a problem causing servers to fail automated health checks, but recovery efforts did not yield the expected results. It subsequently discovered that a core process on affected servers was overwhelmed, leading to capacity loss.

Some servers returned to service but became unresponsive again when traffic was received. To mitigate the issue, Microsoft redirected traffic through alternative routes, temporarily restricted certain types of traffic, and adjusted network protocols. However, these measures resulted in partial recovery across some regions but failed to deliver sustained service restoration.

Microsoft is exploring alternative approaches to address persistent traffic management imbalances and enhance infrastructure stability. In its latest X update, the company stated it is pursuing multiple workstreams to alleviate impact and restore portions of service infrastructure to a healthy state.