Microsoft's Outlook and 365 Services Hit by Global Server Failure

Overview

• Reports began on Thursday afternoon and quickly showed global outages that left Exchange Online/Outlook, Teams, Copilot and other Microsoft 365 services partially or fully inaccessible for many users.
• Microsoft says a subset of servers became unexpectedly unavailable and that failures in a component that handles health checks contributed to overloads while the company continues an active investigation.
• Engineers have applied phased mitigations, including suspending updates, redirecting traffic away from affected infrastructure, restarting troubled servers and validating an alternative health‑check method.
• The interruption caused material effects for businesses and public services worldwide, forcing market operators, governments and hospitals to use phone, messaging apps and even fax as workarounds and delaying some corporate filings.
• As of Friday morning Microsoft reported initial signs of server stabilization and incremental recovery but services remain degraded, no definitive root cause has been confirmed and further status updates are pending.