A major server failure disrupted Microsoft 365 services across the world, cutting off email, calendars and artificial intelligence tools for millions of users.
A widespread Microsoft system failure disrupted workplace email, communications and artificial intelligence tools worldwide on Thursday and Friday, hitting government departments, schools and major technology firms.
According to BBC News, reports of problems with Outlook peaked globally at nearly 140,000 across 74 countries around 18:00 GMT on Thursday, tracked by the monitoring website Downdetector. The disruption crippled connectivity for Microsoft 365 programs, including email on Outlook, calendar apps, file access, and the artificial intelligence assistant Copilot. While some users could still message and hold meetings on Teams, others lost access entirely or found that restored services quickly dropped offline again. More than 430 million people rely on Microsoft 365 applications globally.
Disruption hits schools, airlines and state agencies
As reported by The Guardian, the outage swept from early reports in the United States across the Asia-Pacific region and into Europe. Government agencies in Australia, Japan, Singapore and the US reported system failures. In Australia, the federal police, the nation’s spy agency, courts, schools and public servants faced widespread disruption. Experts predicted the incident would cost Australia billions of dollars, and the Victorian government warned the public about opportunistic scammers taking advantage of the confusion. The Western Australian government said Microsoft was giving priority to life, safety and public services.
In Japan, the disruption forced officials and companies to revert to analogue communication methods. Ryosei Akazawa, the minister of economy, trade and industry, stated the incident had a major impact on the country’s economy. The Japanese digital agency saw its shared communication network go down, prompting Digital Minister Toshiharu Furukawa to turn to text messaging as an emergency measure. Japan’s defence ministry and cabinet office also use Outlook, with officials resorting to posting paper notices on bulletin boards to inform reporters about scheduled press briefings. The shipping company Sagawa Express could not process online bookings for its hands-free luggage system at stations and airports, while drugmaker Taisho moved customer orders to telephone lines. Japan’s meteorological agency noted that its earthquake and severe weather alerts do not rely on Microsoft software.
In the United Kingdom, where the government spends at least 1.9 billion pounds each year on Microsoft software, engineers began working with the technology company to evaluate the damage to public systems. Luke Pollard, the minister for defence readiness and industry, said, “Government engineers and the systems are working with Microsoft at the moment.” London schools warned parents that staff had lost access to Outlook and Teams, asking them to call by phone to report student absences. Wilton Church of England Primary School in Salisbury posted a similar request on Facebook, telling families that global email failures would not stop practical classroom teaching.
Beyond public administration, international airlines and major artificial intelligence developers were pulled into the disruption. Both Anthropic and ChatGPT maker OpenAI reported connectivity troubles tied to Microsoft’s underlying infrastructure, leaving some artificial intelligence tools unable to function as intended.
Server overload behind the breakdown
Microsoft said the breakdown was not triggered by a cyberattack or security incident. Instead, the company traced the failure to a portion of its server infrastructure that buckled under elevated load across several geographic regions.
A large number of servers became unexpectedly unavailable, Microsoft explained, which instantly routed heavy network traffic toward remaining machines and overwhelmed them. The company added that it was looking into configuration issues with the settings applied to servers responsible for maintaining Microsoft 365 operations, alongside problems accessing Exchange Online mailboxes in the Americas.
Cybersecurity expert Troy Hunt told the BBC that Microsoft forms a core piece of the internet’s foundation, adding that the outage showed how dependent daily life remains on email for work tasks, verifying accounts and managing appointments. Gorilla Technology advisory director Paul Spain pointed out that companies facing a day without email effectively lost an entire business day.
Microsoft works to restore services
Microsoft said it was working across several fronts to stabilise its systems and restore access. On social media, Microsoft stated, “We’re aggressively pursuing all pathways to reduce impact.”
Engineers initially applied software fixes in the early hours of Friday morning, but early remediation efforts stalled when the company acknowledged the repairs were not taking as expected. Technicians later deployed a software patch and reported seeing positive results for server stability.
Even with those gains, Microsoft warned that services could remain unresponsive or experience degraded performance across consumer, business and enterprise tiers while recovery operations continue worldwide.
