Microsoft acknowledges fixes have not eased global outage affecting Outlook, Teams and other 365 services
Microsoft said its recent server fixes have not yet restored full functionality to the worldwide outage that has disrupted Outlook, Teams, and other Microsoft 365 applications for thousands of users.
Microsoft reported that recent server fixes have not provided the anticipated relief to a global outage affecting its Microsoft 365 suite, including Outlook, Teams, Word, Excel, PowerPoint, SharePoint, OneDrive and the AI assistant Copilot. Down Detector logged nearly 130,000 user reports of access problems, with many users unable to send or receive email or load inboxes.
The company said it was investigating reports of users experiencing issues accessing Exchange Online mailboxes through multiple connection methods. It later identified a portion of its infrastructure as experiencing elevated load, likely contributing to connectivity errors, after a number of servers became unexpectedly unavailable during automated health checks.
At 21:00 UTC on Thursday, Microsoft validated an alternative health-check method on a subset of affected servers, allowing them to return to service, and began applying the fix more broadly. It also prepared an automated process to detect and restart unresponsive servers and noted that recent configuration updates might be a contributing factor.
By 21:41 UTC, the company was restarting and validating the affected servers and assessing whether reverting a small number of recent configuration changes could accelerate recovery. However, at 22:11 UTC it said the actions taken so far had not provided the anticipated relief and that a core process on the affected servers was becoming overwhelmed.
Microsoft said it was isolating portions of its service infrastructure, restarting affected components, and gradually reintroducing traffic to confirm stability before broader application. It also indicated it was analyzing traffic patterns across its infrastructure and evaluating regional isolation to allow affected regions to recover independently.
An earlier alert on Microsoft’s site said the firm was “aggressively pursuing all pathways to reduce impact” and had paused deployments and configuration changes while reviewing recent updates for any correlation to the event.
Mark Gregory, an associate professor at RMIT University, described the outage as a network-layer issue similar to a 2023 Optus incident, noting that misconfigured servers force customers onto a smaller pool of resources, leading to overload and a cascading failure. He advised companies to invest in testing environments for configuration changes and maintain backup options for cloud-based services.
OpenAI and Anthropic confirmed that the outage affected the Microsoft 365 connector used by ChatGPT and Claude AI. Microsoft also said it had restored Teams functionality in North America, though some users continued to experience connectivity problems.