Microsoft said it had resolved the underlying technical issue that caused the global outage of its services and expressed its “deep regret” over the disruption affecting customers and partners. The company clarified that the cause was not related to a cyberattack, artificial intelligence or autonomous AI agents.
The problem began on November 12 and continued into the following day. Exchange Online — the service that supports email in Outlook — was the most seriously affected. Disruptions also occurred with calendars in Teams, Copilot and SharePoint. The outage affected users in 74 countries and territories, as well as companies, schools and government institutions.
The problem occurred following a network change
According to Microsoft, the technical fault was introduced during an earlier network capacity upgrade and surfaced after a subsequent network change. The load on the affected infrastructure caused difficulties in processing traffic and problems synchronizing changes.
The company restored access gradually because of the scale of demand for its services. It said this approach took more time, but allowed stability to be checked at each successive step. Microsoft reported broad recovery and stabilization of its systems, but warned that individual customers and regions could continue to experience difficulties.
The outage also affected public services
In the United Kingdom, the National Health Service used pre-prepared backup procedures after staff experienced problems accessing email and communication tools. Reports of disruptions also came from schools, government departments and other public organizations in various countries.
Microsoft said it would continue monitoring its services and accumulated email queues before declaring the incident fully resolved. The company will also publish a detailed report with its final analysis of the causes and measures to prevent a recurrence.
Sources: apnews.com, abc.net.au, theguardian.com