Microsoft 365 Outage Restored After Day-Long Global Disruption
Microsoft confirmed on Saturday morning that its services are fully back online, ending a global outage that left millions of users locked out of their email and workplace tools for more than a day. Outlook, Teams and Microsoft 365 were among the services knocked out from Thursday evening, and government agencies in Australia, Japan and the United States were caught up in the disruption.
What caused the outage?
According to Microsoft, the trouble began with an issue introduced during an earlier network capacity upgrade, which surfaced after a recent network change. The fault hit Exchange Online, the company’s cloud email backbone, and then spread to the services built on top of it. Microsoft says it has fixed the underlying problem and will publish a full post-incident report once its review is complete.
Not a cyberattack
Within hours of the outage, speculation about a cyberattack was circulating online. Microsoft moved quickly to shut it down. Charles Lamanna, the company’s executive vice president for Copilot, Agents and Platform, wrote on X late on Thursday that there was no indication the disruption was the result of malicious or cyber activity. The company apologised to customers on X, saying it knew how much trust they placed in its services.
How bad was it?
The problems began at about 16:00 GMT on Thursday, when users found they could not reach Outlook. Within an hour, reports were coming in from 74 countries and territories, and at the peak, Reuters counted more than 130,000 Outlook complaints in the United States alone. Microsoft restored services gradually, checking stability at each stage because of the scale of demand — and some servers that had been brought back online went down again when traffic was redirected to them, which made the recovery harder.
It is the second major Microsoft 365 outage this year. The January disruption lasted almost nine hours and was traced to a data centre in Cheyenne, Wyoming, taken down for maintenance. Last month, an outage of Microsoft’s Azure cloud platform also hit productivity software and industries worldwide.
