Microsoft has acknowledged a widespread outage impacting its Outlook service, specifically the Exchange Online platform, which provides cloud-hosted business email, calendar, contacts, and task management. The issue, first reported around 11:30 a.m. ET on Monday, led to email delays, failures in sending or receiving messages, difficulties in content search, authentication errors, and other mailbox-related problems. By 2 p.m. ET, over 5,000 users had reported the outage on Downdetector, with additional complaints surfacing on social media platforms.
In response, Microsoft stated that it was actively investigating the cause of the disruption. The company identified the problem as stemming from an “authentication component” within the Exchange Online service. Shortly after 12:30 p.m. ET, Microsoft announced that it had devised a potential solution, which it plans to test on a limited segment of its infrastructure. If successful, the fix will be progressively deployed to a broader user base. Source