Microsoft services, including Outlook and Teams, experienced widespread disruption for around 10 hours on Thursday, affecting businesses and government agencies across several regions as the technology company worked to restore its systems.
The problems were linked to the unavailability of several servers, with Microsoft saying its efforts to improve service reliability were progressing more slowly than expected.
In its latest update, the company said it was exploring alternative ways to increase capacity and manage imbalances in network traffic. It had earlier reported that some servers had become unexpectedly unavailable, adding that the disruption was not caused by an increase in traffic.
Outage-tracking website Downdetector recorded more than 130,000 reports of Outlook problems in the United States at around 1pm Eastern Time on Thursday. By 9.30pm, more than 25,000 reports were still being registered.
Users in the Asia-Pacific region also reported problems with several Microsoft services, including in India, Australia and Japan, during the early hours of Friday.
Microsoft said the disruption affected features of Microsoft 365 that depended on Exchange Online and email services. Other functions that did not rely on Exchange Online continued to operate.
Exchange Online is Microsoft’s cloud-based platform for email, calendars, contacts and tasks, and is widely used by organisations to manage communications and workplace operations.
Government agencies affected
Australia’s Home Affairs and Cyber Security Minister Tony Burke said Microsoft believed the incident was not the result of a cyberattack.
Speaking at a press conference, Burke said the company suspected a problem similar in some respects to the CrowdStrike software failure in 2024, when a faulty update caused widespread disruption to computer systems.
He said the impact of the latest incident appeared to be concentrated on email services.
Australia’s intelligence agency and federal police were among the organisations affected on Friday. The US House of Representatives also confirmed that its users had experienced disruption and said its technical teams were working with Microsoft to address the problem.
The CrowdStrike incident in July 2024 caused major interruptions at hospitals, banks, airports and other organisations worldwide, highlighting the risks associated with the global dependence on interconnected technology systems.
Gradual recovery
Microsoft said it was redirecting traffic through alternative routes where possible and working to bring the remaining affected servers back online. It reported that restored servers had remained stable.
The company warned that recovery could take time as users’ devices and applications reconnected to its services.
At 6pm Eastern Time on Thursday, Microsoft reported limited improvement, with users gradually regaining access. However, its later update indicated that restoring normal service remained challenging as traffic management problems continued.
The disruption once again highlighted how heavily organisations depend on Microsoft’s cloud-based communication tools for daily operations, particularly email and collaboration services.
