Microsoft said customers could not connect to several Microsoft 365 services on Thursday. BleepingComputer reported that the list in Microsoft's admin notice included Exchange Online, Teams, SharePoint Online, Microsoft 365 Copilot and Defender XDR. Microsoft said the incident began at 1:26 PM ET. It first blamed heavy load, then said a number of servers had unexpectedly gone offline. That left the remaining servers strained. Microsoft paused deployments, rerouted traffic and began restarting servers. Downdetector, a site that collects user outage reports, showed Outlook complaints peaking at 138,058 around 1 p.m. ET, VnExpress International reported.
By 6:57 PM ET, Microsoft said some servers were back and stable, and it saw limited recovery. It said a core process on the affected servers was overwhelmed, which cut capacity. It was checking whether undoing a few recent configuration changes would speed things up. Microsoft has not said when service will be fully restored. It has not said whether this outage is linked to an earlier Teams problem that day, which ran from 9:45 to 10:53 AM ET and is resolved. It has not said what made the servers drop out.
The outage reached tools built on Microsoft 365. OpenAI said Microsoft connectors might fail on new connections. Anthropic said an upstream provider issue affected its Microsoft 365 connector. VnExpress also reported that truck maker Workhorse Group moved its earnings report from November 12 to November 16, citing the disruption. Teams that depend on Microsoft mail, chat or AI tools can see one provider fault stop several services at once.