Microsoft confirmed a widespread outage affecting Outlook users, causing email delays, authentication issues, and problems with other key functions. The issue was linked to its Exchange Online service, a cloud-based platform used by businesses for email, calendars, contacts, and tasks. Microsoft first reported the problem on X (formerly Twitter), noting that users might experience reduced functionality across various Exchange Online features. The company was analyzing service data and diagnostics to pinpoint the cause of the disruption. Initially, Microsoft said it was looking into user reports of Exchange Online issues. Later, it identified a problem with an "authentication component"—a system that verifies user identities—which was causing the outages. The company was testing a potential fix on a portion of its infrastructure to see if it resolved the problem. If successful, the solution would be rolled out more widely. However, the authentication issue was not limited to Exchange Online; it was also affecting other Microsoft services. The outage began around 11:30 a.m. ET on Monday, according to the crowdsourced outage tracking site Downdetector. By 2 p.m. ET, the site had recorded over 5,000 reports of the issue. Many users also took to social media, particularly X, to express frustration with the disruptions. Those affected reported delays in sending or receiving emails, problems searching their mailboxes, authentication errors, and issues with other message-related tasks. As of 5 p.m. ET on Monday, Microsoft was still working to fully resolve the problem. The company has not yet provided a timeline for when normal service might be restored, but it continues to monitor the situation and test possible solutions.