CNBC reported on 12 November 2026 that a Microsoft outage affected Outlook, Teams and other Microsoft 365 services across regions, leaving users unable to reach mailboxes and collaboration tools. Microsoft said the main problem was with Microsoft 365 services, primarily Exchange Online, and began publishing service-health updates as it worked to restore service.
The disruption began shortly before 13:00 EST. Outage-tracking site Downdetector showed thousands of user reports during the incident.
Services affected
Reports covered Microsoft 365, Outlook and Teams. Service-status information also named Exchange Online, SharePoint Online, Copilot, Microsoft Defender XDR and OneDrive among affected or potentially affected services.
Microsoft first described Teams problems in North America and Exchange Online mailbox access issues in the Americas. It later said the Exchange Online issue could affect Microsoft 365 service connectivity for users in any region. For the Teams issue, Microsoft said its mitigation actions had restored service health and functionality.
Users also reported problems with Word, Excel and PowerPoint during the wider Microsoft 365 disruption. The main operational effect for many tenants was mail access, with users unable to send or receive messages or load inboxes normally.
Cause and recovery work
Microsoft initially said affected infrastructure was experiencing “elevated load across multiple regions”. It later said the load was not driven by an increase in traffic, but by a number of servers being unexpectedly unavailable, which strained the remaining infrastructure.
The company also said some servers were failing automated health checks. Microsoft said the failed checks might originate from a component responsible for processing server health, and that it had taken steps to prevent additional servers from being affected while it returned affected servers to service.
At 21:00 UTC, Microsoft said it had validated an alternative service health check method that allowed a subset of affected servers to return to service. It said it was applying that change more broadly and preparing automated recovery systems to detect and restart unresponsive servers.
Microsoft also paused deployments and configuration changes while it reviewed recent changes for any correlation with the incident. Later updates said recent configuration updates were a potential cause, but the investigation was still continuing.
Other platform reports
Amazon Web Services said its services were operating normally and pointed customers to its health dashboard. It said an unrelated disruption elsewhere on the internet had prompted inaccurate reports about AWS outages.
Google users also reported issues on Downdetector. The available Microsoft updates did not describe the incident as an AWS or Google cloud outage.
Tenant planning consequences
For Microsoft 365 admins, the incident is a reminder that service-health information and local user reports often arrive at different speeds. Tenant teams still need a way to tell staff what is unavailable, what workarounds are approved and which internal channels remain usable when Outlook or Teams is affected.
Mark Gregory, associate professor in the School of Engineering at RMIT University, said the pattern appeared to involve a smaller pool of available servers carrying more users. He said businesses reliant on cloud services such as Microsoft 365 should have backup options.
That does not mean replacing Microsoft 365 for day-to-day work. It means testing how the organisation communicates during a Microsoft 365 outage, how business-critical processes behave when mail or Teams is unavailable, and which decisions depend on Microsoft’s own service-health updates.
A Microsoft 365 outage that takes Exchange Online, Outlook, Teams and Copilot out of normal use turns adoption into an operational question, and ECS's M365 + Copilot topic deals with that reality alongside Copilot, Teams, SharePoint, Viva, governance and adoption. The programme gives attendees sessions and practitioner experience on tenant rollout, service dependency and continuity choices. Bring outage communication plans, continuity assumptions and tenant-specific questions for discussion at the conference.
This article was written by the ECS editorial team with the assistance of Amal Agent, run.events' AI assistant, which supported the research, drafting and proofreading.