Millions of people could not open their email or join a Teams meeting on Thursday and Friday after a Microsoft outage swept across at least 74 countries. Outlook, Teams and Copilot went down for offices, schools, hospitals and government departments from the Americas to Europe and Asia. Microsoft said it was working to restore services, but some servers it brought back online failed again.
Problems began at about 16:00 GMT on Thursday, when users started reporting that Outlook would not load. Within an hour, the outage tracker Downdetector had logged reports from 74 countries and territories. Microsoft first said it was investigating problems in the Americas, then confirmed that users in any region could be affected. The company said its affected infrastructure was under unusually high load across multiple regions, and later that a number of servers had become unexpectedly unavailable. Microsoft said the load was not caused by a rise in traffic.
For anyone who relies on Outlook or Teams to do their job, the outage meant missed meetings, undelivered client emails and delayed work. Offices that run on Microsoft 365 had to fall back to phone calls and personal email. Congressional offices in Washington reported being paralyzed, and government systems in Singapore and Japan were disrupted. If your business runs on Microsoft’s cloud, the incident shows why you need a backup way to reach customers and staff.
Microsoft said early on Friday it had seen only “marginal success” in restoring services, more than 12 hours after the outage began. The company said it was reviewing server performance and confirming that patches had been applied and were working after infrastructure reboots. It has not confirmed how many users were affected.
How far it spread
Downdetector recorded at least 43,000 reports of Outlook problems from users in 72 countries by about 07:00 GMT on Friday. The real number is far higher, because the tracker only counts people who visit the site to report an issue. Walter Pasquarelli, an affiliate researcher at the Bennett School of Public Policy at the University of Cambridge, noted that about 430 million people use Microsoft services. In the UK, police, NHS services and schools were affected, and the Supreme Court of the Philippines reported communications problems.
Microsoft said there was no indication that the outage was caused by a cyber attack. The disruption came as the US Cybersecurity and Infrastructure Security Agency disclosed an actively exploited Outlook zero-day vulnerability, a separate issue that can expose NTLM password hashes. Security researchers said the flaw is being used in the wild.
The most striking detail in Microsoft’s own account is the word “marginal.” More than 12 hours after the outage began, the company said it had seen only marginal success in restoring services, and that servers it had restored were failing again. For a service used by about 430 million people, that is an unusually blunt admission.
Is the Microsoft outage a cyber attack? No. Microsoft has said there is no indication the outage was caused by a cyber attack. The company attributed the failure to unexpectedly unavailable servers and elevated load across regions, and said the load was not caused by an increase in traffic.
Microsoft says it is still working to restore full service and has not given a firm timetable. Downdetector reports had eased by Friday morning in some regions, but users continued to report problems. Check Microsoft’s service health page and Downdetector for live status before assuming an outage is over.
