More than 2,100 people had reported issues with Microsoft 365 on the website Down Detector as of 10:30 a.m. EST on Monday, with 86% of reports coming from issues with Outlook, 9% with Exchange and 6% with Sharepoint.

A post to the Microsoft 365 account on X, formerly known as Twitter, said most users were having issues accessing Exchange Online—a cloud-based email server—and Microsoft Teams calendars.

Microsoft said it had started to deploy a fix as of 9 a.m.—shortly after reports of issues started spiking significantly—which includes "manual restarts on a subset of machines that are in an unhealthy state,” but did not give an estimated time for full restoration.

The company added that a "recent change" was likely responsible for the outage and that the change has been reverted. While Microsoft did not specify what change impacted programs, Monday morning was also the rollout of a new Recall AI tool for Windows Insiders that is meant to take regular snapshots of computer activity—essentially a "photographic memory" for computers—to store on PCs and make searchable later without remembering exact keywords or dates.

The feature first debuted in May but its initial version was criticized for privacy and security concerns, leading the full launch to be postponed.