Global Microsoft Outage Disrupts Services Worldwide As Recovery Efforts Continue

A major overnight Microsoft outage has disrupted services worldwide, affecting Microsoft 365 applications including Outlook, Teams, and the artificial intelligence tool Copilot. Organizations across multiple sectors, including healthcare providers, schools, police forces, and government platforms, have experienced widespread connectivity and communication issues.

Microsoft ruled out a cybersecurity incident or cyber-attack, attributing the failure to an "elevated load" on its infrastructure. According to the company, a large number of servers became unexpectedly unavailable, diverting heavy traffic to the remaining operational infrastructure and putting severe strain on those systems. Professor James Ferryman from the University of Reading's computer science department explained that the server component responsible for establishing secure connections became overwhelmed, causing a snowball effect across the network that requires a gradual, phased restoration.

Widespread Impact Across Sectors and Tech Industry

The disruption extended beyond internal Microsoft applications. Tech companies OpenAI and Anthropic reported operational problems linked to the event, with OpenAI investigating connectivity issues that degraded tool performance. Globally, affected entities ranged from US city governments and court systems in Los Angeles and Texas to Australian intelligence agencies and Japan's shared government IT platform. In Canada, a healthcare network managing several Toronto hospitals reported email difficulties, though patient care remained unaffected. In the UK, GP surgeries, pharmacies, schools, and major police forces encountered service disruptions.

Although Microsoft 365 serves over 430 million users globally, the total reach of the outage remains unconfirmed. Monitoring platform Downdetector logged over 140,000 incident reports regarding Outlook from users in 74 countries on Thursday evening. Former lead software engineer Gergely Orosz noted that the event could rank as the most disruptive business email outage of all time due to its prolonged duration, while cybersecurity expert Troy Hunt highlighted the critical reliance on Microsoft's infrastructure for basic business and daily verification communications.

Status of System Recovery

By Friday afternoon, Microsoft reported encouraging progress in Europe alongside improvements in North America. The company noted that email queues were significantly reduced and approaching normal operational levels. However, Microsoft cautioned that users may continue to face intermittent access issues and delayed email deliveries as restoration actions proceed.

To protect delayed communications while delivery queues catch up, Microsoft extended its email timeout window—the period Outlook waits to receive a message—to 48 hours. Delayed messages will display the timestamp of when they were actually delivered rather than when they were initially sent.