Microsoft Ends 36-Hour Global Outage; Restores All Services, Including Outlook and Teams

Microsoft has officially resolved a massive global outage that disrupted its core workplace software suite for more than 36 hours, confirming on Saturday that all affected services—including Outlook, Microsoft Teams, and Copilot—have been fully restored.

The disruption, which began early Thursday morning, marked one of the longest service breakdowns in the tech giant's history.

At its peak, nearly 130,000 users across dozens of countries reported issues on the outage-tracking platform Downdetector. However, the total impact likely extended far wider given Microsoft 365’s base of over 450 million paid commercial users.

Businesses, universities, and government agencies across the United States, Europe, Australia, and Japan experienced severe interruptions to daily operations.

According to Microsoft’s service health updates, the incident primarily stemmed from failures within Exchange Online, the cloud-based platform that powers email and calendar functions.

Several servers unexpectedly went offline after failing automated health checks, creating a cascading effect. As traffic was rerouted to a smaller pool of remaining infrastructure, those servers became overwhelmed and repeatedly froze when engineers attempted to bring them back online.

Beyond preventing users from accessing Outlook inboxes or sending emails, the Exchange Online failure crippled key scheduling and calendar integrations in Microsoft Teams, disabled Microsoft 365 Copilot’s ability to pull workplace data, and even disrupted third-party AI connectors used by OpenAI and Anthropic.

To stabilise the network, Microsoft paused all routine configuration updates—which an internal review flagged as a potential trigger—and implemented an alternative health-check method alongside traffic restrictions.

Engineers gradually brought servers back online region by region, starting with the Asia-Pacific before expanding recovery efforts to North America and Europe.

In a statement apologising for the prolonged downtime, Microsoft acknowledged the disruption caused to customers and partners, noting that restoring services gradually was necessary to ensure long-term stability under heavy demand. The company also confirmed that it found no evidence of a cyberattack or malicious activity behind the incident.

While normal operations have resumed and email backlogs have cleared, industry analysts warn that repeated high-profile cloud outages could prompt enterprise customers to re-evaluate their reliance on single-vendor ecosystems.

Microsoft stated it will publish a full post-incident review once its technical investigation concludes.