Microsoft’s cloud productivity suite suffered a major disruption on Thursday, November 12. The outage cut off Outlook email, Teams, SharePoint, and Copilot for users across the Americas and beyond. By late evening on the US East Coast, Microsoft had not declared the incident over.
How it unfolded
Nearly 130,000 users reported problems accessing Outlook on the outage tracker Downdetector just after 1 p.m. ET. Microsoft first said it was investigating Exchange Online mailbox access problems in the Americas, and later said the issue could affect Microsoft 365 connectivity in any region. The impact went beyond email. Microsoft’s service list included Exchange Online, Teams, SharePoint Online, Copilot, Defender XDR, Planner, To Do and Intune.
What Microsoft says went wrong
Microsoft said some of its infrastructure was under elevated load across multiple regions because a number of servers became unexpectedly unavailable. The company said the load was not caused by a rise in traffic but by servers failing automated health checks. It paused all deployments, moved traffic off the affected systems, and began restarting servers. A separate Teams problem earlier in the day was fixed, though Microsoft has not said whether the two incidents are connected.
Downdetector, which monitors user-reported service disruptions, recorded approximately 110,449 Outlook outage reports as of 12:02 a.m.
Recovery comes in fits and starts
By mid-afternoon, Microsoft had validated an alternative health check method that brought a subset of servers back, and it began applying the change more broadly. By 5 p.m. ET, however, it said its repair attempts had not delivered the relief it expected. Around 6 p.m. it reported that part of the affected fleet was back and stable but warned that servers could become unresponsive again once traffic reached them.
At about 7 p.m. ET it said restored servers were failing again under traffic, that it was temporarily limiting which traffic types could reach the affected infrastructure, and that it was rebuilding some servers from a previous configuration to test a fix. Microsoft had not named a root cause or given a time for full restoration, and it said users should expect a gradual recovery as clients reconnect.
Public services and businesses feel the effects
New York City’s emergency management department warned residents of possible delays in email delivery and responses from city agencies and advised calling 311 for non-emergency matters and 911 for emergencies. Reuters reported that the disruption also caused problems with connectors used by AI services from OpenAI and Anthropic, and that truck maker Workhorse Group postponed its third-quarter results announcement to November 16 because of the outage. Amazon Web Services said it was operating normally, and that inaccurate reports of an AWS outage were circulating.
A rough year for the service
This is not the first major disruption of 2026. In January, a Microsoft 365 outage lasted nearly ten hours, which Microsoft blamed on a portion of its North American infrastructure not processing traffic as expected.
Note: This is a developing story, and Microsoft 365 Status on X carries the latest updates.
