Microsoft says Outlook.com outage is causing sign‑in failures

Microsoft is investigating an active Outlook.com outage causing intermittent sign-in failures, 'too many requests' errors, and unexpected sign-outs. Downdetector has received thousands of user reports since the incident began. Microsoft has classified it as 'service degradation' but has not yet disclosed the root cause, affected regions, or user count. The investigation is focused on client sign-in scenarios and interactions across service components.