Microsoft Exchange Online Outage Causes Widespread Disruptions
Microsoft's Exchange Online service suffered an outage on August 31, disrupting Outlook email, sign-ins, and mailbox operations for some business and enterprise customers. The company reported that authentication deployment was the cause of the issue.
The disruption led to degraded functionality across Exchange Online, affecting users' ability to connect to mailboxes, send and receive messages, and access other related services such as Teams, OneDrive for Business, SharePoint Online, Purview, and Defender XDR.
Microsoft said it was working on a remediation and testing it on part of the affected infrastructure before deploying it more widely. The company reported that it was experiencing a staged restoration, with mailbox connectivity returning to normal by late August 31, but search functionality still being restored and messages queued during the disruption taking time to clear.
The available reports indicate that the outage was broad enough to produce a pronounced public reporting spike, with nearly 6,000 Outlook-related reports on Downdetector at its peak. However, these figures do not represent the total number of affected people or mailboxes, but rather a snapshot of voluntary problem reports.