Microsoft 365 Outage Hits Outlook and Teams as Servers Fail

The Microsoft 365 outage is disrupting access to Exchange Online, Microsoft's cloud-hosted email and calendar service, and wider Microsoft 365 connectivity on Nov. 12, 2026, according to the official Microsoft 365 Status account on X, @MSFT365Status. Microsoft first reported Exchange Online mailbox access issues in the Americas at 9:54 a.m. PT, then said at 10:07 a.m. PT that users in any region may be affected; Engadget's Anna Washenko reported on Nov. 12 that Outlook, Teams and other Microsoft 365 services were among the impacted platforms.

The outage is ongoing as of 12:15 p.m. PT, and Microsoft has not given a time for full recovery. In its latest update at 11:50 a.m. PT, Microsoft said it was testing a configuration change for a problem that causes servers to fail automated health checks and become unavailable, while also restarting affected servers and monitoring their return to service.

What caused the Microsoft 365 outage?

Microsoft said at 10:35 a.m. PT that a portion of infrastructure was experiencing elevated load across multiple regions, which was likely contributing to connectivity errors. Microsoft later said at 11:31 a.m. PT that the elevated load was not driven by an increase in traffic, but by a number of servers being unexpectedly unavailable, straining the remaining infrastructure.

The Microsoft 365 admin center incident ID, meaning the reference number admins use to track a specific service incident, lists EX1550543 and MO1550821 for this event. Microsoft said at 10:48 a.m. PT that it had begun redistributing connection traffic across broader worldwide infrastructure, then said at 11:12 a.m. PT that it paused all deployments, moved more traffic off affected infrastructure and restarted affected servers.

We're investigating reports of users experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas. More details can be found in the Microsoft 365 admin center under EX1550543.

— Microsoft 365 Status (@MSFT365Status) November 12, 2026

Which services are affected?

Microsoft's first notice named Exchange Online mailbox access through multiple connection methods in the Americas. Microsoft then broadened the scope, saying the issue may affect Microsoft 365 service connectivity for users in any region, while Engadget reported Outlook and Teams among the impacted platforms.

This incident follows an earlier Microsoft outage that hit Outlook, Teams and Office 365 in the US, a separate disruption that also affected core productivity apps. Microsoft has not said the Nov. 12 incident is related to that earlier outage.

Microsoft also dealt with earlier Outlook email issues as it deployed a fix, but the company has not attributed the current incident to those previous Outlook problems.

What can users and admins do right now?

• Admins should check EX1550543 and MO1550821 in the Microsoft 365 admin center for tenant-specific details.
• Users without admin center access should monitor Microsoft's public status page.
• Avoid making unnecessary client-side configuration changes until Microsoft posts further guidance.
• Use temporary communication channels for urgent work if Outlook or Teams access is unstable.

Analysis: A server-side failure across multiple regions matters because many businesses run email, meetings and collaboration inside a single cloud suite. Microsoft's updates point to unavailable servers and failed automated health checks, not a traffic surge, so the business impact is about dependency concentration rather than any confirmed external cause.

For a separate Microsoft reliability issue this week, Microsoft also has a Windows 11 KB5132061 install failure fix due Friday. That Windows update issue is separate from the Microsoft 365 outage described by @MSFT365Status on Nov. 12.