Is a cyberattack behind the Microsoft outage? Here's why Teams, Outlook, Microsoft 365 and other apps are down

Microsoft outage: The tech giant is still working on its servers to restore the services after a massive outage hit Outlook, Teams, Copilot and several Microsoft 365 applications across multiple regions. The disruptions started in the early hours of November 13 leaving users in several countries struggling to access emails, join meetings and use Microsoft's cloud-based productivity tools.

Now with many services experiencing massive downtime, there are also concerns about the possible cyberattack. However, Microsoft has clarified that the disruption is not related to a cybersecurity incident. There is also no indication of a hacking attack, and no cybercriminal group has claimed responsibility at the moment.

Instead, the company has traced the problem to internal infrastructure issues involving server capacity and a recent configuration change. Microsoft is continuing to investigate the technical failure under incident ID EX1550543.

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Why are Microsoft Outlook, Teams, 365 and other services not working?

According to Microsoft's engineering updates, the outage is linked to problems with the server processes responsible for establishing secure connections. Some servers unexpectedly became unavailable after failing automated health checks reducing the infrastructure available to handle incoming requests.

This created additional pressure on the remaining servers, causing some core processes to become overwhelmed and stop responding. The resulting drop in available server capacity triggered further connectivity problems across Microsoft's services.

Microsoft has also identified a recent configuration update that coincided with the beginning of the disruption. Engineers are evaluating a rollback of the changes as part of their recovery efforts.

The initial attempts to restore services have not gone entirely as planned. Microsoft said some servers brought back online became unresponsive again when user traffic returned. This has forced its engineering teams to restore capacity gradually while redistributing network traffic and investigating alternative recovery measures.

Which Microsoft services are affected?

The Microsoft outage has affected many services. Outlook and Exchange Online have experienced some of the most significant problems, with users reporting difficulties accessing inboxes, sending emails and connecting through desktop, web and mobile applications.

Microsoft Teams has remained partially functional, with some existing chats and meetings continuing to work. However, features that depend on Exchange, including meeting scheduling and certain group chat functions, have also experienced issues.

SharePoint Online, OneDrive and Copilot have reported intermittent connectivity problems and degraded performance. The Microsoft Store and some Microsoft Defender services have also been affected.

Microsoft Azure's core cloud infrastructure appears to be largely operational, suggesting that the disruption is primarily concentrated within Microsoft's productivity and related services.

When will Microsoft services be restored?

Microsoft has not provided a confirmed timeline for the complete restoration of its services. Its engineering teams are gradually bringing servers back online and balancing network traffic and working on configuration changes to stabilise the affected infrastructure.

Users and IT administrators can check the Microsoft 365 Service Health dashboard for updates. Administrators can also find details about incident EX1550543 through the Microsoft 365 Admin Center under Health and Service health.