Global Outage of Microsoft 365 Affects Outlook, Teams, and ChatGPT

On November 12, 2026, Microsoft 365 experienced a major outage that continued into November 13. Users in various countries faced issues accessing corporate email via Outlook and Exchange Online. The disruptions also affected certain functions of Teams, Copilot, and services working with Microsoft data through APIs.

Why Outlook Mail Stopped Working

According to notifications from Microsoft, the Exchange Online outage began on November 12 at 16:17 UTC. An overload of the process responsible for secure connections led to some servers ceasing to process requests. The company restarted infrastructure, redistributed traffic, and increased computing power.

By 07:25 UTC on November 13, a configuration fix improved the stability of some servers. However, in an update at 09:03 UTC, Microsoft reported that recovery was ongoing and service throughput remained below normal. The company found no signs of malicious activity; the root cause of the incident is still being determined.

Which Microsoft 365 Functions Became Unavailable

Issues arose with sending and receiving emails, accessing mailboxes, and calendars. In Teams, some users experienced problems with meeting scheduling and invitations, although main chats and calls mostly remained available. The outage also affected Microsoft 365 Copilot and Defender for Office 365 functions.

Outage Impacted ChatGPT, Claude, and Government Agencies

OpenAI reported connection errors with Microsoft 365 in ChatGPT. Anthropic noted widespread failures in mail, calendar, and search queries through the corresponding connector Claude. This concerns integrations with Microsoft, not the shutdown of the AI models themselves.

The Ministry of Finance of Japan, certain government services in Singapore, and the office of the U.S. Tenth Circuit Court of Appeals reported email issues. Microsoft did not specify the exact timeline for full service restoration.