Microsoft 365 Outage Hits Outlook and Teams
Server issues caused a global Microsoft 365 outage affecting Outlook, Teams and Copilot for hours.
TL;DR
- Microsoft 365 services including Outlook and Teams went down worldwide starting November 12.
- The root cause was servers becoming unavailable and failing health checks.
- Engineers paused deployments, shifted traffic and restarted servers to restore access.
Microsoft 365 services including Outlook, Teams, Copilot and several others faced a global outage that began on November 12 and stretched into the next day. Users in the Americas reported problems first, with issues later spreading to other regions including Asia.
What broke
The company traced the trouble to servers that became unexpectedly unavailable. This put extra load on the remaining infrastructure even though traffic had not spiked. Affected servers failed automated health checks, and a component handling those checks appeared to be part of the problem.
Microsoft listed the Exchange Online issues under incident EX1550543 and later tied broader service problems to MO1550821. No malicious activity was detected.
Recovery steps
Engineers paused new deployments, shifted traffic to alternate routes and restarted affected servers. Some servers that came back online later became unresponsive again. The company tested configuration changes on subsets of servers and added temporary traffic limits in certain locations while monitoring stability.
Partial recovery appeared in some regions as servers returned to service, but full restoration had no announced timeline. Microsoft said it will release a post-incident report once the outage ends.
The Tea
Even the biggest cloud setups can trip over their own health checks when a few servers flake out. For teams that live inside Outlook and Teams, the outage was a blunt reminder that productivity tools are only as reliable as the hidden infrastructure behind them.
Sources
- MediaNama: Microsoft 365 applications hit by global outage for over 10 hours
- Inc42: Microsoft 365 Outage Disrupts Outlook, Teams Globally
- The Verge: Microsoft Outlook is still down
- Engadget: Multiple Microsoft 365 services are experiencing an outage
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