Microsoft Outlook outage disrupts Microsoft 365

On Thursday, Microsoft said Outlook email was down for business and consumer users after a large number of servers unexpectedly became unavailable. The problem was first flagged in the U.S. and the Americas before expanding to any region. Microsoft said Teams, SharePoint, Copilot, Defender XDR, OneDrive and Office for the web were also affected, and that it was redistributing connection traffic and investigating.

By early Friday, the disruption had reached users in Japan, Singapore and Hong Kong, with Outlook problem reports peaking at nearly 140,000 around 18:00 GMT on Thursday. In Hong Kong, financial sector workers, including staff at Goldman Sachs and Nomura, reported disrupted email and offline work. In the UK, hospitals, GP surgeries, pharmacies, police and schools were affected, with NHS England telling patients to keep attending appointments unless told otherwise.

Microsoft said the outage was caused by servers unexpectedly becoming unavailable, straining remaining systems, and warned that some restored services could become unresponsive again. OpenAI said it was investigating issues with its connections to Microsoft. Microsoft later said services were gradually being restored and the problems did not appear to be a cyber-attack.