Microsoft 365 outage affects Outlook, Teams and other services

Microsoft’s first update, posted to X at 12:54 p.m. ET, said customers in the Americas were having trouble with Exchange Online mailboxes. Exchange Online provides cloud-based back-end support for Outlook.

By 1:07 p.m. ET, the company said the disruption could affect Microsoft 365 connectivity in any region. Its status page warned that users might be unable to connect to multiple services. The status page itself briefly went offline, according to multiple Mashable reporters.

Microsoft had not determined the root cause. It said the elevated load was not caused by an overall increase in traffic, but by a large number of servers becoming unexpectedly unavailable and shifting load onto the remaining infrastructure. The company said it was investigating why the servers were failing and working to return them to service safely.

In later updates, Microsoft said it had found no recent change that correlated with the outage. It added that failed health checks might originate in a specific component responsible for processing server health. The company said it was working both to prevent further servers from being affected and to restore those already down.