Microsoft 365 outage continues as recovery efforts stall, disrupting Outlook, Teams, Copilot and more

Microsoft is still working to restore full service after a major global Microsoft 365 outage that began on November 12, 2026. Users in multiple regions continue to face connectivity problems accessing email, collaboration tools, AI features and related services. The company says it has found no evidence of malicious activity and is pursuing multiple workstreams to recover backend servers and manage traffic imbalances.

The disruption is tracked under incident IDs EX1550543 for Exchange Online and MO1550821 for the broader Microsoft 365 suite. Features that interact with Exchange Online and email services are primarily affected, while elements that do not depend on them remain functional. Users may be unable to access their Exchange Online mailboxes through Outlook on the web, the Outlook desktop client via MAPI, Exchange ActiveSync, or REST-based connections, and email delivery may be delayed. In Microsoft Teams, most core functionality including joining calls, meetings, group chats and channel messages continues to work, but scenarios that depend on Exchange Online such as calendar scheduling, invites, viewing and meeting edits can fail, as can the creation of Live or Virtual events, certain Copilot responses that rely on Outlook, calendar or Microsoft 365 files, and the ability to create or delete private or shared channels. Microsoft 365 Copilot users may be unable to load Copilot Chat or receive responses in web and desktop apps, and Copilot experiences may be unable to access work data such as email, calendar and files. Other impacted areas include parts of the Microsoft 365 admin center, Microsoft Graph API requests that access Exchange Online data, Microsoft Defender for Office 365 features such as Safe Links and quarantine operations, Microsoft Defender XDR portal pages, Microsoft Purview services including labeling and data loss prevention, certain Intune device scenarios, Planner, To Do, Power BI and Microsoft Fabric exports involving sensitivity labels, Universal Print, and some Windows 365 Cloud PCs configured with Microsoft Purview Customer Key.

The elevated load and connectivity failures stem from Exchange Online traffic imbalances created when a large number of servers unexpectedly became unavailable after failing automated health checks. With fewer healthy backend servers able to accept and process requests, the remaining infrastructure was forced to handle a disproportionate share of the traffic. Microsoft has stated that the elevated load was not driven by an increase in overall user traffic volume, but by the sudden loss of server capacity, which strained the systems still in service. Subsequent mitigation efforts, including traffic rebalancing and attempts to return servers to service, produced further imbalances: routing services generated surges in outbound calls when they could not properly direct requests to backend machines, and restored servers sometimes became unresponsive again once they began receiving traffic. These sustained traffic management imbalances have complicated recovery, as the company works to identify the underlying cause of the original server failures, scale capacity, optimize routing and carefully repair affected infrastructure without triggering additional instability.

As of early November 13, Microsoft reported that changes applied to improve serviceability were not taking effect as expected. The company is identifying alternate workstreams to increase capacity amid the sustained traffic management imbalances and is continuing work on recovering frontend servers while implementing further traffic optimization actions. It is taking a measured approach to identify and repair affected infrastructure and is tracking results to confirm recovery and performance. Microsoft has emphasized that it is treating the incident with urgency and priority until full resolution and has confirmed it is not aware of any malicious activity. A full post-incident report covering root cause and defense-in-depth repairs is expected once the incident is mitigated.

Administrators can check the latest details in the Microsoft 365 admin center under EX1550543 and MO1550821, or through Microsoft’s public status resources if the admin center is unavailable. This is a service-side incident, and users are generally advised not to reset passwords, reinstall clients or make local configuration changes in an attempt to resolve it. Core functionality that does not depend on Exchange Online interaction may still work in some applications. The outage has affected businesses, schools, government services and individual users worldwide as Microsoft continues efforts to stabilize the infrastructure and restore normal capacity. Further updates are expected as recovery progresses.