A problem with Microsoft (MS)'s cloud authentication system left some business services, including corporate email, not functioning properly for hours.
According to TechCrunch and other foreign media on the 1st, on the 31st MS's corporate email service "Exchange Online" experienced access and usage disruptions. Some users were unable to log in to their account or faced delays and failures when sending and receiving emails. It was also reported that some features, such as mail search and synchronization, did not work smoothly.
The disruption was not limited to Exchange Online. MS said it confirmed that a problem arising in authentication-related components affected other services as well. Exchange Online is a service that helps corporations manage email, calendars, contacts, and task information in the cloud.
MS analyzed service operation data and diagnostic information and narrowed the problem point to authentication-related components. It then prioritized applying recovery measures to some systems and checked whether services were returning to normal. The company said it would expand the scope of application as the effects of the measures are confirmed. However, it did not disclose when all services would be fully restored.
On the outage-tracking site Downdetector, user reports surged from around noon Eastern time on the 31st, and the number of reports at one point exceeded 5,000. Posts alerting access issues with Outlook and Exchange Online also appeared one after another on social media.