Microsoft services gradually recover after global outage disrupts email and collaboration tools

Microsoft said its email services are "approaching normal levels" more than 20 hours after a global outage began, noting that email queues have been significantly reduced but some users may still face intermittent access or delayed delivery. The company added that recovery progress is encouraging in Europe and that further stabilization efforts are underway across all regions.

The fault has been traced to Exchange Online, the backend system that powers Outlook, Teams and Copilot. James Ferryman, a computer-science professor at the University of Reading, explained that the system became overwhelmed, causing a cascade of connection failures as devices repeatedly attempted to reconnect.

UK government departments are activating contingency plans. A deputy spokeswoman for the Prime Minister said officials are working with Microsoft to assess the impact and that frontline services have alternative arrangements to maintain essential operations.

The outage has affected a range of public and private organisations. Schools, councils and NHS trusts reported loss of email access, prompting phone-based communication and paper workarounds. The GMB union warned that ambulance and NHS 111 services faced a "massive backlog" due to the inability to refer patient details electronically, though emergency call-outs remain functional.

Airlines in India experienced flight cancellations, while Amazon Web Services confirmed normal operation. AI platforms such as OpenAI's ChatGPT and Anthropic's Claude reported connector issues linked to the Microsoft incident.

Users in the UK logged thousands of reports of Outlook and Claude problems on outage-tracking sites, with numbers gradually declining as services recover. Microsoft indicated that traffic is being restored in the Asia Pacific region and that email timeout periods have been extended to 48 hours to preserve delayed messages.

"We’re seeing encouraging recovery progress in Europe, with service availability and email delivery performance improving across a growing portion of affected Microsoft 365 infrastructure," Microsoft said in its latest status update.

"We’re working with departments and with Microsoft to establish the full picture, and where services are disrupted, departments have contingency arrangements in place," the government spokeswoman added.

The incident underscores the reliance of modern workplaces on a few large cloud platforms and the need for backup plans when critical services fail.