why is microsoft outlook not working

Microsoft Outlook is currently experiencing a widespread service outage caused by unexpected server failures across Microsoft 365. The disruption began on Thursday, November 12, 2026, around 12:30 p.m. ET, impacting users globally who are trying to access Exchange Online mailboxes, send or receive emails, and load their inboxes.

Microsoft reported that the issue stems from a specific component responsible for processing server health checks, which unexpectedly took a number of servers out of service and strained the remaining infrastructure. Engineers have deployed an alternative service health check method and activated automated recovery systems to restart unresponsive servers, gradually bringing affected accounts back online.

What Is Affected

• Primary Impact on Enterprise Users. The outage primarily impacts business and enterprise customers using Microsoft 365 and Exchange Online rather than standalone consumer accounts.
• Other Connected Services. Alongside Outlook, users have reported connectivity errors across Microsoft Teams, SharePoint Online, Microsoft Copilot 365, Defender XDR, and To Do.
• Widespread Reports. Outage tracker Downdetector logged a peak of nearly 130,000 Outlook issue reports early Thursday afternoon, though those numbers have steadily declined as recovery efforts continue.

What You Can Do

• Wait for Server Recovery. Because this is a server-side infrastructure issue under incident codes EX1550543 and MO1550821, local troubleshooting steps like reinstalling the app will not resolve the connection errors.
• Monitor Live Updates. You can track real-time restoration progress on the Microsoft 365 Service Health Status page or through the official Microsoft 365 Status X Account.
• Troubleshoot Local App Freezes. If your service region has already been restored but your desktop app remains stuck, follow the Microsoft Support Outlook Troubleshooting Guide to force-close background tasks in Task Manager and restart the application.