Microsoft works to restore Outlook, 365 and other services after global outage
Microsoft said it is addressing a server issue that caused widespread downtime of Outlook, Microsoft 365 and other apps, and reported partial recovery while continuing remediation efforts.
Microsoft announced that it is continuing efforts to improve server stability and restore traffic flow after an outage that affected Outlook, Microsoft 365 and several other services for millions of users worldwide. In an update posted at 8:36 p.m. Pacific time, the company said it observed partial recovery in some regions but that the improvement had not been sustained, and it was reviewing additional actions to enhance overall stability. A later update at 9:01 p.m. Pacific time added that multiple workstreams were engaged to alleviate impact, address the current blocker and return portions of the service infrastructure to a healthy state.
By 6 p.m. Pacific time on Thursday, Microsoft reported "positive results" from efforts to restart the affected servers and said it was actively monitoring performance to verify stability. The investigation identified a process on the affected servers responsible for establishing secure connections that became overwhelmed, causing the servers to stop processing requests. Microsoft said it was preparing a configuration change to address the behavior, testing it on a subset of servers before broader deployment, and reverting a recent network configuration change that coincided with the outage. Temporary traffic limitations were applied in specific locations while the company monitored stability before gradually reintroducing additional traffic.