Microsoft reported an outage involving its sprawling set of software tools early Thursday afternoon. The outage, which the company said may affect business and consumer users in “any region”, has continued for at least four hours, customers reported.

Between 5.15pm and 6pm the outage tracker Downdetector showed that more than 130,000 users were experiencing problems with Microsoft Outlook, which is used for email, calendars and other online tasks.

Similar spikes in outages were reported with Microsoft 365, the workplace messaging app Microsoft Teams, the artificial-intelligence assistant Microsoft Copilot and the Microsoft Store, Downdetector’s data showed.

The number of reported outages fell steadily across the afternoon. By 10pm, the number of users reporting issues with Microsoft Outlook had dropped by more than half.

Microsoft said initially that part of its infrastructure was “experiencing elevated load”.

Later the company said in a social media post that “we determined the elevated load isn’t driven by an increase in traffic, but by a number of servers being unexpectedly unavailable, straining the remaining infrastructure”.

The company said about 6.45pm that it had begun redistributing connection traffic across its broader worldwide infrastructure to help balance the load, and that it was restarting affected servers to return them to service.

“We’re working to safely return them to service,” Microsoft added in an update. – The New York Times