Microsoft Probes Server Health Checks After Microsoft 365 Outage

Microsoft is investigating failed automated server health checks and recent configuration changes after servers became unavailable and increased load across Microsoft 365, disrupting email, meetings and cloud files.

The company’s investigation found that a large number of servers unexpectedly became unavailable, leaving the remaining infrastructure under greater pressure. Some servers were taken out of service after failing automated health checks. Microsoft is examining why those checks failed.

Microsoft is also reviewing recent configuration changes because some updates may have contributed to the incident.

Users in multiple regions reported trouble accessing Outlook, Exchange Online, Microsoft Teams, OneDrive, SharePoint and Microsoft 365 Copilot. Some could not send or receive email, load mailboxes or access cloud files.

Microsoft had previously tied the incident to unexpected server unavailability; the health-check findings add a new detail to the ongoing investigation. Microsoft is continuing to investigate the failed checks and any connection to recent configuration updates.