Microsoft is investigating a widespread outage affecting several Business and Enterprise Microsoft 365 services, including Outlook. Here are the details.

Based on information available on (which is seemingly also facing reliability issues), users “may be seeing degraded service functionality or be unable to access multiple Microsoft 365 services.”

The incident began around2:00 p.m. ET and was attributed to backend infrastructure issues:

A portion of dependent service infrastructure in the North America region isn’t processing traffic as expected.

In its lastest status update, Microsoft said that the affected infrastructure had been restored, but recovery was still in progress as traffic was redistributed across healthy systems:

While we’ve restored the affected infrastructure to a heathy state, further load balancing is required to mitigate persistent impact. We’ve identified and are implementing additional actions to direct requests and traffic to additional healthy sections of infrastructure to achieve withstanding recovery.

Initially, Microsoft noted that impacted features included, but were not limited to:

• Sending and receiving email through Exchange Online, including notification emails from Microsoft Viva Engage.
• Collecting message traces.
• Searching within SharePoint Online and/or Microsoft OneDrive.
• Accessing the service portals, including Microsoft Purview, Microsoft Defender XDR, and the Microsoft 365 admin center.
• Creating chats, meetings, teams, channels or adding members in Microsoft Teams.
• Receiving presence or location information in Microsoft Teams.
• Applying and managing sensitivity labels, interactive operations on reports, and artifacts with sensitivity labels in Microsoft Fabric.”

In addition to the updates to its status page, Microsoft has also been posting updates on X. The company expects to publish its next status update at 6:00 p.m. ET:

We’ll keep monitoring the situation and update this post as it develops.