Microsoft Outlook outage disrupts email services for users

At about 10:40 am ET on Thursday, Microsoft posted on its 365 status page on X that it was investigating reports of users experiencing issues when accessing or using Microsoft Teams functionality in North America, and by just before 1 pm ET it said it was aware of issues accessing Exchange Online mailboxes through multiple connection methods in the Americas.

The company later explained that its network was seeing elevated load across several regions, which it said was likely adding to the connectivity errors, but it attributed the problem to servers going offline rather than to the increased traffic. About an hour later Microsoft announced it had begun redistributing connection traffic across its worldwide infrastructure to balance the load and was aggressively pursuing all pathways to reduce impact. “We've paused all deployments. We're moving additional traffic off the affected infrastructure, and we're restarting affected servers to return them to service,” Microsoft wrote.

In a subsequent update Microsoft listed the affected services as Exchange Online, Microsoft Teams, SharePoint Online, Microsoft Copilot 365 and Microsoft Defender XDR. A Microsoft spokesperson told WIRED, “We are aware and investigating reports of users experiencing issues with Microsoft 365 services, primarily issues with Exchange Online.” Reports on Downdetector started to rise around 1:15 pm ET after a spike in users reporting Outlook and other 365 product problems around noon. In an X post just before 3 pm ET Microsoft said a “problem” was “causing servers to fail automated health checks and become unavailable” and that it was attempting to reboot the systems.

Outages in cloud services are common and can stem from configuration errors, DNS resolution issues or cyber‑attacks, though Microsoft said there is no indication a cyberattack caused this incident. While large‑scale Microsoft outages are relatively rare, they are not unprecedented; in July 2024 a corrupted update from Crowdstrike knocked out Azure services for several hours, resulting in significant revenue loss for affected companies. The outage’s end time and exact cause remain unknown.