Overview
- A major interruption to Outlook, Teams, Copilot and other Microsoft 365 services began on Thursday evening and, after staged fixes and backlog processing, Microsoft reported full restoration by Saturday morning.
- Microsoft attributed the failure to a network‑capacity upgrade that introduced a configuration problem which overloaded a process used to establish secure connections, and the firm reverted the change while increasing capacity.
- Millions of users and many organizations worldwide lost or had limited access to email, calendar and collaboration tools, forcing some public services to use paper records or suspend processes such as visa handling.
- Media-circulated estimates that the outage could cost billions and trigger large pro‑rata refunds are model-based and unverified, while Microsoft continues backlog processing and monitoring before issuing a detailed post‑incident report.
- The incident has intensified calls from governments and industry for redundancy, diversification and stronger European or open‑source alternatives to reduce dependence on a single foreign cloud provider, building on earlier 2026 outages that raised similar concerns.