Microsoft infrastructure failure causes global outage for Microsoft 365 services

Microsoft experienced a global infrastructure failure on November 12, 2026, that disrupted multiple Microsoft 365 services for users across various regions. The outage impacted users in the United States, Portugal, and several other global locations. Microsoft confirmed that users may be unable to connect to various Microsoft 365 services during the incident.

Affected Microsoft services and impact

The technical failure impacted a wide range of essential productivity tools and security services. According to the company, the affected services included Outlook (Exchange Online), Microsoft Teams, Microsoft Copilot, SharePoint Online, Microsoft Defender XDR, and OneDrive. While initial reports suggested the incident was limited to the Americas, Microsoft later updated the scope of the incident to a global scale.

Data from Downdetector indicated a massive surge in user reports during the disruption. At 13:27 local time on November 12, 2026, the platform recorded over 130,000 issues related to Outlook and approximately 46,000 issues related to Microsoft 365. Additionally, Downdetector reported 3,000 issues involving Microsoft Teams. Around 13:30 US East Coast time, media reports reported that approximately 120,000 Outlook issues had occurred.

Root cause and technical response

Microsoft identified the cause of the infrastructure failure as an elevated load on a portion of the system. This load occurred because several servers became unexpectedly unavailable, which placed additional strain on the remaining infrastructure. Microsoft clarified that the elevated load was not driven by an increase in traffic volume from users.

The company identified the specific incident using internal codes EX1550543 and MO1550821. In an attempt to resolve the disruption, Microsoft attempted a configuration change, but the company stated that this action did not provide the expected relief. Following the unsuccessful configuration change, Microsoft began a gradual recovery process. This process involved restarting affected servers and redirecting network traffic to alternative routes to stabilize the system.

Current status and service recovery

As of 23:00 on November 12, 2026, Microsoft reported that some restored servers remained stable. While the core services are undergoing recovery, the company noted that users might experience delays in email delivery. These delays occur as message queues are processed following the restoration of the services.

Microsoft 365 Status stated that the elevated load is due to servers becoming unexpectedly unavailable, which strained the remaining infrastructure, rather than an increase in traffic. The company continues to monitor the stability of the restored servers to ensure full service functionality across all affected regions.

Glossary

• Microsoft 365 — Microsoft 365 is a suite of applications and services. It includes various productivity tools and services that can be integrated into Windows.
• Microsoft Teams — Microsoft Teams is a Microsoft service. It is used for building connections and can host various apps.
• Microsoft Copilot — Microsoft Copilot is a generative artificial intelligence chatbot developed by Microsoft AI. It is based on the Microsoft Prometheus large language model.
• SharePoint Online — SharePoint Online is a cloud service within the Office 365 platform. It is used for internal social networking, collaboration, and public websites.