Microsoft meltdown: Caused by AI? A cyber attack? Your questions answered

Microsoft services including Outlook, Teams, Copilot and parts of its cloud platform suffered widespread disruption, affecting customers around the world. The outage matters because Microsoft 365 services used by hundreds of millions rely on Exchange Online for email and related functions, and some users were left unable to access them.

Microsoft said the incident began at 4.17pm UK time and involved server failures, elevated infrastructure load and an imbalance in traffic within Exchange Online. Downdetector recorded nearly 140,000 Outlook problem reports by 6pm, while reports across five services peaked at 19,650 a minute; Microsoft said there was no indication of a cyber attack, and AI services appeared to be affected as a consequence rather than causing the outage.