Microsoft outage takes down Outlook and Teams worldwide, Exchange Online fault cuts mail chat and security monitoring in every region

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When will Microsoft Outlook be restored? Here's what we know fox13seattle.com

Microsoft's Outlook and Teams went dark for users worldwide on Thursday, together with a string of other Microsoft 365 services, locking office workers out of mailboxes and meeting rooms across every region. The outage began around 9:45 a.m. Pacific time, and within half an hour Microsoft had confirmed that connectivity could be affected for users in any region — which, for a vendor with customers on every continent, meant all of them.

The company traced the trouble to Exchange Online, the mailbox infrastructure beneath its mail service. The list of affected products reads like a medium-sized company's entire software shelf: Teams for chat, Copilot, Defender XDR for security monitoring, Planner, To Do and Intune for device management. When one supplier provides the mail, the meeting room, the task list and the security dashboard, a single fault takes them all down together, everywhere at once. Defender XDR's place on the list means organisations that lost their inboxes also lost the dashboard that watches for intruders — both run through the same vendor.

There was nothing to fail over to. The whole point of the arrangement is that mail, calendars, meetings and task lists live in one place, managed by one counterparty, and when that counterparty's infrastructure breaks the fallback plan is to wait. Engineers spent the afternoon returning affected servers to service and reported that the restored portion was holding stable. Recovery, Microsoft said, would be gradual, with tools returning as devices and apps reconnected.

The status updates themselves went out through the Microsoft 365 Status account on X, a platform Microsoft does not run — the channels customers would normally use to check on their tools were the tools that were down. Companies that moved their communication into a single vendor's cloud bought efficiency and received a single point of failure in exchange. Microsoft promised its next update by 4:30 p.m. Pacific time.