Here’s a summary/analysis of the news article "Microsoft blames Outlook outage on another dodgy code change" from The Register: Summary
Incident: On March 19, 2025, users of Microsoft’s email service experienced a worldwide outage on Outlook’s web version, which blocked access to Exchange Online mailboxes.
Cause: Microsoft attributed the issue to "a recent change made to a portion of Outlook on the web infrastructure," which negatively impacted service.
Resolution: Microsoft reverted the change, which restored access to affected users. The company acknowledged the issue on social media, first admitting something was wrong, then confirming it was a recent change that caused the incident.
Pattern: The article notes this kind of incident is “depressingly commonplace,” referencing a major outage earlier in March (also blamed on “dodgy code”).
Impact: While end users lost access to email, the burden fell heaviest on enterprise administrators, who had little recourse other than contacting Microsoft support.
Broader Issue: The article points to the risks and complexity inherent in massive cloud services, where a single engineer’s mistake can affect tens of thousands of customers, and stresses the importance of rigorous testing and understanding before production deployments.
Accountability: The Register asked Microsoft about its change validation processes and guarantees for preventing recurrence, but received no initial response.
Update: After publication, a Microsoft spokesperson said, "We are working to enhance our detection of similar events and reduce the time needed to identify, mitigate, or prevent such impacts."
Key Takeaways
Outages caused by failed updates are a recurring issue for Microsoft’s cloud-based services.
The response time and communication have improved, but such incidents cast doubt on Microsoft’s change management and testing rigor.
End customers and especially IT administrators feel the brunt of downtime and repeated disruptions.
Microsoft claims it is working to improve its detection and mitigation processes for such events.