Microsoft 365 is experiencing an outage. Here’s what to know.

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.

On social media service X, Microsoft posted a message early Monday that it is assessing “an issue impacting users attempting to access Exchange Online or functionality within Microsoft Teams calendar.” The problem appears to be affecting Microsoft users globally, according to posts from users.

“We’ve identified a recent change which we believe has resulted in impact. We’ve started to revert the change and are investigating what additional actions are required to mitigate the issue,” Microsoft added in a subsequent post. 

Microsoft 365 is a subscription-based app that packages services like Word and Excel, while also providing cloud-based storage, while Teams is primarily used by workplaces for video calls and online chat. Although DownDetector, an online service that tracks tech outages, only had a few dozen reports of problems with 365 as of early Monday morning, users posted on social media that they were experiencing issues with the Microsoft services.

University of Galway “is aware of an issue impacting some Microsoft 365 services, including Outlook, Outlook Calendars, Teams etc,” noted the Irish university’s IT group on X. “This is an intermittent issue impacting Microsoft 365 customers globally. Microsoft is aware & investigating.”

When did the outage begin?

Reports of outages began at about 4 a.m. Eastern Time, according to DownDetector. By 10 a.m., there were about 2,000 reports from people saying they were having problems with Microsoft 365, the outage detection service said.

Monday’s problems with Microsoft 365 comes after a massive outage in July, when banks, airlines, health systems and other industries that rely on the service were hit by a technical problem caused by global cybersecurity firm CrowdStrike. 

The disruption, which led to thousands of flights and train services being canceled globally, spawned a number lawsuits, with Delta Air Lines suing CrowdStrike and Microsoft over the outage, which took down the airline’s internal systems and caused chaos for travelers. 

Is Outlook down?

Some users reported problems with Microsoft Outlook, including trouble connecting to the service as well as sending emails, according to DownDetector. 

“Outlook 365 is really spotty this morning. Experiencing intermittent email outages,” one user wrote on DownDetector. 

Others said they were having trouble accessing their OneDrive files, which are documents saved on the cloud. 

Has Microsoft given an update?

At 9 a.m. Eastern Time, Microsoft said it was working on a solution to fix the issue, although it didn’t provide a time frame for when its apps would be back up and running.

“We’ve started to deploy a fix which is currently progressing through the affected environment,” Microsoft wrote on X. “While this progresses, we’re beginning manual restarts on a subset of machines that are in an unhealthy state.”

Shortly before noon, Microsoft said the patch had been deployed to roughly 98% of the “affected environments” that “our targeted restarts required for mitigation are being performed as quickly as possible.”