Global Microsoft outage disrupts Outlook, Teams and Copilot for users around the globe

Microsoft scrambled overnight to contain a global outage that knocked out email and collaboration services for users in at least 74 countries, after a failure in parts of its cloud infrastructure triggered connectivity problems across Microsoft 365. Reports of problems with Outlook surged to nearly 140,000 around 18:00 GMT on Thursday, more than 2,000 times the normal level, according to monitoring site Downdetector, which said issues began shortly after 16:15 GMT and persisted for at least eight hours. Outlook, Teams and the AI assistant Copilot were among the affected services, leaving many users unable to send or receive emails or access calendar details, though Microsoft said messaging and online meetings remained largely functional. The company ruled out a cyberattack, attributing the disruption to “elevated load” after a large number of servers became unexpectedly unavailable, straining the rest of its infrastructure.

The company's updates on X told the story of a fix that kept slipping away. Hours after announcing that engineers had “seen positive results” restarting affected systems, Microsoft said the changes were “not taking as expected”, as servers it returned to service became unresponsive again once traffic resumed. Its latest messages described a core process on affected servers “becoming overwhelmed, causing capacity loss”, and said the company was pausing deployments, rerouting traffic and exploring whether reverting recent configuration updates could accelerate recovery. Microsoft said it had no indication of malicious activity and vowed to treat the incident “with urgency and priority until full resolution”.

The fallout stretched from Asia to the Americas: Singapore's government technology agency reported government emails down, Japan's deputy chief cabinet secretary said the national IT infrastructure was affected, and India's Air India and IndiGo rerouted email services to keep customer queries flowing, with flight operations unaffected. Even AI rivals felt the pain: OpenAI and Anthropic both reported issues connected to Microsoft's services. Cybersecurity expert Troy Hunt told the BBC that the outage showed “Microsoft is a massive part of the internet backbone and reminds us how critical email still is”, while New Zealand technology analyst Paul Spain said companies had effectively “lost a business day”.