Microsoft 365 Outage Drags On for Nearly 10 Hours, Affects Millions

Microsoft 365 suffered a widespread outage on January 22-23, with services including Outlook, Teams, and SharePoint unavailable for nearly 10 hours as North American infrastructure failed to process traffic.

Timeline

The disruption began around 11:40 a.m. Pacific time on January 22. Complaints on Downdetector spiked at around 3 p.m. ET, with 16,000 users reporting problems. Microsoft acknowledged the issue at 19:37 UTC. Services were restored by approximately 2:28 AM ET on January 23.

Services Affected

The outage impacted Exchange Online email, file searching in SharePoint Online and OneDrive, and creating chats, meetings, or adding members in Teams. Defender and Purview were also affected. Users reported internal mail flowing slowly while external email stopped entirely.

Root Cause

Microsoft confirmed the outage was caused by "a portion of service infrastructure in North America that is not processing traffic as expected." Engineers redirected traffic to alternate infrastructure while working to restore normal operations.

Resolution

Microsoft stated on January 23 that "impact has been resolved," though the company noted that "further load balancing is required to mitigate the effects." The incident adds to what has been described as a troubled start to 2026 for Microsoft's cloud services.