Microsoft investigating mailbox outages

Microsoft is currently investigating a nationwide outage affecting mailboxes, including Outlook.

“We’re investigating reports of users experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas,” Microsoft 365 Status posted on X Thursday morning.

We’re investigating reports of users experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas. More details can be found in the Microsoft 365 admin center under EX1550543.

— Microsoft 365 Status (@MSFT365Status) November 12, 2026

Microsoft determined a portion of infrastructure is experiencing an elevated load across multiple regions, which could be contributing to the connectivity errors.

“We’ve begun redistributing connection traffic across our broader worldwide infrastructure to help balance the load,” the company stated.

Microsoft said it is looking into every pathway to reduce the impact. It also paused all deployments and is moving additional traffic to the affected infrastructure.

“We’re restarting affected servers to return them to service,” the company stated.

The City of Tacoma also reported that its website is unavailable as many city employees are experiencing outages.

This is a developing story, check back for updates.

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