Microsoft is investigating an issue with its Microsoft 365 service and its Teams app, with some users reporting to DownDetector that they are having problems using services such as Exchange and Outlook.

Higher than normal U.S. outage reports began as the workday kicked off on the East Coast and peaked hours later in the early afternoon before tapering off, according to the tracking site Downdetector. Worst hit was the web version of Outlook, with the phone and desktop apps faring better, the site said.

Microsoft said most Outlook and Teams services had been restored as of Monday evening, after more than 24 hours of technical delays.

User reports on Downdetector show issues with Microsoft 365, Teams, Outlook, and the Microsoft Store began around 5 a.m. ET on Monday. In a series of posts to X, the Microsoft 365 Status account explained that at around 2 a.

Microsoft said Monday that it has identified the cause of a major Outlook and Teams outage, and is deploying a fix to the problem.

A Microsoft outage on Monday has affected Outlook and Teams users. Microsoft is aware of the issue and working on a fix, but said it's "facing delays in our recovery efforts." Reports of issues began around 8 a.