Microsoft 365 Outage Hits Thousands of Enterprise Customers

Microsoft acknowledged on Monday afternoon that thousands of its enterprise customers were experiencing problems accessing their email as they returned from the weekend. The issues affected Exchange Online and other Microsoft 365 business services, including OneDrive for Business, SharePoint Online, and Microsoft Teams. Initially, users took to social media and platforms like DownDetector to report problems with Microsoft Outlook.

Microsoft confirmed that service to Exchange Online had been disrupted due to an 'issue within a core authentication configuration used by multiple Microsoft 365 services.' The company is actively testing a remediation strategy to resolve the issue as quickly as possible. According to its official status page, Microsoft 365 admins can see MO1465074 and/or EX1464935 for the latest updates on the disruption.

Microsoft says it's continuing to review recent changes to the service to definitively confirm the source of the problem. The company provided an update at 6:01 p.m. ET, stating that it appreciates its customers' patience while services are restored. This is a developing story and will be updated as more information becomes available.