Microsoft 365 is degraded after servers went offline

Microsoft has marked Microsoft 365 business and enterprise services as degraded. The public status page listed that degradation at 3:30 p.m. Eastern on November 12, and it says administrators may be unable to open the admin center for service-health details.

The public status page listed a degradation at 3:30 p.m. Eastern. The page is carrying the notice because the usual admin-center view may be out of reach. Customers who cannot open that view are pointed to the same public page.

Exchange Online mailboxes have been hard to reach in the Americas. Microsoft is investigating reports that users cannot open those mailboxes through more than one connection method. That work is tracked as EX1550543. A later update said the connectivity problem may affect Microsoft 365 users in any region, not only the Americas.

The strain comes from servers that became unavailable, not from a rise in traffic. The remaining infrastructure is under load because those servers dropped out. Microsoft is working to return the unavailable servers to service. That part of the incident is tracked as MO1550821, alongside the mailbox reports.

Microsoft has paused deployments and is moving traffic off the affected systems. It is also restarting the servers that dropped out, and it is testing a configuration change aimed at servers that fail automated health checks. The updates describe that work as still underway.

The public page still shows a degradation, not a return to normal service. The incident codes for more detail are EX1550543 and MO1550821 in the admin center, when that center is available.