Microsoft tests remediation for extended Outlook service disruption

Microsoft confirmed on Monday that a multi-hour outage disrupted Outlook and other Exchange Online services, causing email delays, authentication errors and problems with mailbox operations. The company posted on X that it was reviewing service telemetry and diagnostic data to isolate the source of the issue. > "We’ve confirmed that users may experience degraded functionality with various Exchange Online functionalities. We’re reviewing service telemetry and diagnostic data to isolate the source of the issue," the statement read.

Engineers traced the problem to an authentication component that also affected services beyond Exchange. Microsoft said it is testing a remediation strategy on a portion of its infrastructure and will expand the fix if successful. User reports of the outage began around 11:30 a.m. ET, with more than 5,000 complaints logged by 2 p.m. ET on the crowdsourced monitoring site Downdetector, and additional complaints posted on social media.