By Amara Osei

Downdetector, the user-reporting platform, logged more than 130,000 US Outlook problem reports at Thursday's peak, as Microsoft's global Microsoft 365 disruption entered a second day Friday. Microsoft had issued no timeline for full recovery by its 06:11 a.m. ET update, despite a fix making servers more stable, better mailbox access and improved processing of delayed email.

What caused the disruption?

Microsoft first flagged the incident around midday ET Thursday, saying users across the Americas faced difficulty accessing Exchange Online, its hosted email infrastructure. A follow-up X post warned the issue could affect any region. By Friday morning, Microsoft's public status page still showed service degradation for Microsoft 365, its productivity suite, across business customers and consumer products.

Microsoft attributed elevated loads across multiple regions to a number of servers that had unexpectedly become unavailable. The company said an increase in customer traffic had not caused the strain, ruling out a demand surge as the explanation. In its 3:34 a.m. Thursday update, Microsoft said it had "no indication" that malicious activity caused the disruption.

Microsoft restarted servers as part of its response. Early Friday, it warned that servers initially returned to service could become unresponsive again once traffic reached them. That sequence left Microsoft managing unstable capacity even as traffic returned to affected systems.

How far has recovery progressed?

Microsoft's 06:11 a.m. ET Friday update reported "additional progress toward recovery." The company said some mailbox access and delayed email processing were improving, but users could still encounter intermittent issues. Outlook remained unavailable for some users, and Microsoft had not published a target for restoring every affected service.

The distinction matters because recovery did not equal normalization. The status page continued to show degradation on Friday morning, while returning servers retained the potential to fail under renewed load.

Which services and AI connectors are affected?

Microsoft's service advisory identified a broad set of affected products. Its list included:

• Outlook, the email application.
• Teams, the workplace messaging and meetings platform.
• SharePoint, the collaboration and content-management service.
• Copilot, Microsoft's AI assistant.
• Microsoft Defender, the endpoint security platform.
• Intune, the device and application management service.
• Power BI, the business-intelligence and analytics platform.
• Other Microsoft 365 products that rely on Exchange Online.

The shared Exchange Online dependency explains the incident's breadth, according to Microsoft's advisory. Third-party AI providers Anthropic and OpenAI said on their status pages that their Microsoft 365 connectors were disrupted. Anthropic also reported authentication issues, meaning failed identity verification, affecting Claude Code, its coding tool, but did not attribute them to the Microsoft outage.

What operational impact has the disruption caused?

Many workers could not use email or Teams systems, interrupting routine communication. Downdetector's total reflected user submissions rather than a confirmed count of affected people or businesses, so it measured complaint volume rather than Microsoft's customer total.

Reuters reported on Thursday that the outage had affected US House of Representatives users and that electric-truck maker Workhorse Group postponed its quarterly earnings call. Air India said on Thursday that it had rerouted email services, while IndiGo said on Friday that its email support channel was disrupted. Both airlines said their flight operations remained unaffected.

AP reported that government agencies in Singapore, the Philippines and Japan had reported knock-on effects. The breadth reflects Microsoft's list of dependent products and the third-party connector failures Anthropic and OpenAI reported.

For enterprises, the immediate operational test is stable server capacity rather than another partial restoration, because Microsoft identified renewed traffic on returning servers as a failure mode. Until the status page clears the incident and Microsoft sets a full-recovery time, customers cannot treat improved access as a durable return to normal operations.