Microsoft rules out 'malicious activity' as cause for global outage

Microsoft announced on Thursday that it was working to resolve a global outage affecting its Microsoft 365 applications, including Outlook and Teams. The company confirmed that its efforts to repair the major Outlook disruption were not proceeding as expected, prompting it to seek alternative solutions.

In a statement, Microsoft said it was "not aware" of any malicious activity that could have caused the widespread service interruption. The tech giant reported having successfully restored service health and functionality, though it has not provided a timeline for when the issue will be completely resolved.

Global Impact

Outage tracker Downdetector received reports from 74 countries and territories within about an hour of the disruption beginning. The outage blocked users from accessing email and other services, also impacting Microsoft 365 connectors used by companies OpenAI and Anthropic, which reported their tools were not functioning properly.

Downdetector logged nearly 130,000 reports of Outlook problems shortly after 1 p.m. EST (1800 GMT). Some customers experienced difficulties sending and receiving emails, while others found the program entirely inaccessible.

Service Disruptions

The Microsoft 365 cloud-based subscription service, which also includes the Teams workplace messaging app and the AI assistant Copilot, experienced multiple outages. Microsoft initially noted that users were "experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas," with part of its infrastructure "experiencing elevated load" that was "likely contributing to connectivity errors."

The company revealed that some restarted servers stopped responding again once traffic returned. In an update at 0254 GMT Friday, Microsoft stated its latest changes had not worked as expected and that it was exploring other methods to restore service. This marks the second disruption to Microsoft's 365 services this year.