A widespread outage disrupted Microsoft’s Outlook email service and other apps on Thursday, Nov. 12, as users reported difficulty accessing accounts, sending and receiving messages, and connecting to workplace services.

More than 120,000 users had reported Outlook problems to outage-tracking website Downdetector by about 1:30 p.m. ET, according to CityNews reporting credited to News Staff and The Associated Press. Reports included messages that would not send or arrive, as well as email delays.

Thousands of users also reported problems with Teams, Microsoft’s workplace messaging app, its Copilot AI assistant and broader Microsoft 365 services. The Downdetector figures reflected user reports rather than a Microsoft-confirmed count of affected accounts.

Microsoft initially said in social media updates that it was aware of users “experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas.” That statement described mailbox access problems extending across more than one way of connecting to the service.

In a later update, the company said part of its infrastructure was “experiencing elevated load,” which it described as “likely contributing to the connectivity errors.” Microsoft said it would begin redistributing traffic to help balance that load. Its explanation remained qualified, rather than a definitive account of the outage’s cause.

The company subsequently broadened its warning, saying the issue could affect Microsoft 365 service connectivity for users in any region while mitigation work continued. It directed customers to incident EX1550543 in the Microsoft 365 admin centre for more information.

Earlier Thursday, Microsoft had said it had “successfully restored” problems affecting Teams in North America. Some users nevertheless continued reporting connectivity issues. Microsoft did not immediately provide further information, according to the CityNews report.

Sources