Microsoft 365 outage linked to unavailable servers as recovery continues

Microsoft 365 users faced connectivity problems on Nov. 12 as the company worked to restore affected services, Global News reported. Microsoft initially described trouble accessing Exchange Online mailboxes in the Americas, then warned the disruption could affect connectivity in any region.

Global News reported that Microsoft’s explanation shifted during the day: the company first pointed to elevated infrastructure load, then said unexpectedly unavailable servers were shifting load onto the systems still running. Its latest reported update described further recovery work after earlier efforts had not brought the expected relief.

• Microsoft said connectivity could be affected in any region; administrators could check incident EX1550543 in the Microsoft 365 admin center.
• Downdetector had recorded more than 100,000 outage reports around 1:30 p.m. Eastern, Global News reported. That tracker count is not a verified tally of unique users.
• Microsoft described isolating infrastructure, restarting affected components and reintroducing traffic to test a possible recovery.

Microsoft traced the load to unavailable servers

Microsoft also said it had not found a recent change that correlated with the start of the impact. It said failed automated health checks might originate in a component responsible for processing server health. Around 4 p.m. Eastern, an alternative health-check method had allowed some affected servers to return to service, the company said; it was extending the change and preparing automated recovery systems.

Microsoft said its response included pausing deployments, moving traffic away from affected infrastructure and restarting servers. It tested a configuration change while monitoring server health. Shortly after 5 p.m. Eastern, the company said its actions had not provided the anticipated relief. It described isolating infrastructure, restarting affected components and reintroducing traffic to validate a possible recovery.

Which services were affected by the outage

ABC News reported that Microsoft’s service-health listing warned users might be unable to connect to Exchange Online, Teams, SharePoint Online, Copilot 365, Defender, Planner, To Do, Intune, Purview and Power BI. Hindustan Times also reported problems accessing Outlook and Exchange Online mailboxes through multiple connection methods. Microsoft directed administrators to incident EX1550543 for updates.

What it means for connected services

ABC News reported problems with Microsoft connectors used by OpenAI and Anthropic during the disruption. That concerns those connections, rather than establishing an outage across either company’s products. The incident followed a separate Microsoft 365 disruption in September that lasted several days. TechCrunch reported that Microsoft attributed that earlier incident to a core authentication configuration issue; it does not establish the cause of the November outage.

Global News placed the initial rise in outage reports shortly after noon Eastern on Nov. 12 and the latest cited Microsoft update shortly after 5 p.m. The update described ongoing recovery actions, but did not establish when service would be fully restored.