Updated at 3:47 p.m. CT:Microsoft’s official service health status page has been updated to reflect what users have been reporting for hours: this outage extends well beyond Exchange Online alone.

At the time of writing, Microsoft’s status page now lists a broader “service degradation” affecting Microsoft 365 for both Business and Enterprise customers, according to the company. The updated list of impacted services includes OneDrive for Business and SharePoint Online, Exchange Online, Microsoft Teams, and both Microsoft Purview and Microsoft Defender XDR.

he company says it’s continuing to test its mitigation strategy to make sure the fix doesn’t introduce new problems, while also exploring other ways to reduce the impact in the meantime.

Notably, the update comes after the status page had reportedly shown many of these services as operating normally, even as users across X and Reddit spent much of the day describing widespread login failures, missing emails, and inaccessible files. Microsoft Azure and consumer-facing Microsoft products remain listed as unaffected.

Updated at 4:19 p.m. CT: Microsoft has offered a more specific explanation for what’s driving the ongoing disruption. In its latest update, the company said its investigation suggests a “misconfiguration issue” is stopping authentication components from deploying correctly to part of its infrastructure.

Our investigation indicates that a misconfiguration issue may be preventing authentication components from deploying as expected to a portion of infrastructure, and we're reexamining recent changes made to the service to determine why this is occurring. Additionally, we are…

— Microsoft 365 Status (@MSFT365Status) August 31, 2026

In plain terms, it just means that an internal change to Microsoft’s authentifcation system cause parts of it to not roll out properly. And now engineers at Microsoft are retracing those changes to pinpoint the cause.

Microsoft Outlook appears to be down for a significant number of users as of Monday late morning. According to Downdetector, reports of Outlook problems spiked sharply just before 11:16 a.m. ET, jumping from around 37 reports to over 6,000 in a short window.

Credit: DownDetector

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Of the issues users are reporting, the largest share involves receiving messages, followed by app-related problems and login issues, per Downdetector’s tracking. Microsoft acknowledged the outage on its Microsoft 365 Status account on X.

We're investigating reports of Exchange Online issues. Please see EX1464935 in the admin center for more information.

— Microsoft 365 Status (@MSFT365Status) August 31, 2026

The company stated it was investigating reports of Exchange Online issues, pointing users to incident EX1464935 in the admin center for updates.

About an hour later, Microsoft followed up to confirm the scope of the problem, saying it had verified that users may be experiencing degraded functionality across various Exchange Online features. The company said it was reviewing service telemetry and diagnostic data to pin down the root cause.

We've confirmed that users may experience degraded functionality with various Exchange Online functionalities. We're reviewing service telemetry and diagnostic data to isolate the source of the issue. For more information, please see EX1464935 in the admin center.

— Microsoft 365 Status (@MSFT365Status) August 31, 2026

At the time of this writing, Microsoft’s status account posted a more specific update, stating it had identified an issue with an authentication component that contributed to the disruption. According to the post, Microsoft has “developed a remediation strategy” and is testing it to confirm it resolves the impact before rolling it out more broadly. However, as of this writing, Microsoft’s Service Health Status page says that all its products are “currently operational.”

Mashable contacted Microsoft with questions about the potential outage, and we’ll update this story if we receive a response.

The outage has stirred up plenty of frustration online. On X, users have pushed back on Microsoft’s “degraded functionality” language, with one commenter calling it “one way to say ‘none of our shit works.’”

Others reported the disruption stretching on for hours, with entire offices and thousands of employees affected worldwide, according to posts under Microsoft’s status updates.

A parallel Reddit thread in r/Outlook saw a similar flood of confirmations from users locked out of the service, with dozens simply chiming in with variations of “down for me” and “yep, whole company having issues.”

This is a developing story…