Microsoft 365 users reported outages, saying they were unable to sign into their email accounts or access other applications. Downdetector, a website that tracks tech outages, estimated that over 24,000 users faced issues around the peak of the disruption around 9 a.m. ET.

The issue affected Teams, which many companies use for internal communications. X user Larry Pritchard commented: "Holler if you’re at work doing nothing cuz of the Microsoft outage."

Later in the morning on Thursday, Microsoft said that the systems were back up and running. Sorry, Larry.

How long was Microsoft 365 down?

According to Downdetector, more than 24,000 users reported Microsoft 365 outages around 9 a.m. ET Thursday. By 9:30 a.m., the number was back down to just under 3,500. At 10:45 a.m., Microsoft shared on X that the issue had been remedied.

What Microsoft apps experienced problems?

Outlook had the most outages, with 75% of reports centering around the email app. Seventeen percent of users had issues with server connections and 8% with Onedrive.

What was the issue that caused the Microsoft outage?

The Microsoft 365 Status account on X posted around 10:45 a.m. ET, saying the company had "confirmed that impact has been remediated."

In a series of posts leading up to the resolution, Microsoft said the problems stemmed from a change within a "third-party ISP (internet service provider's) managed-environment."

After the ISP reversed the change, Microsoft reported signs of recovery.