Microsoft Outlook Down? Here’s Exactly When the Email Service Will Be Fixed—and What to Do Until Then

Millions of users worldwide asked “when will Outlook be fixed?” today after Microsoft 365 mailboxes began timing-out around 12:30 p.m. ET. According to Microsoft’s service-health feed on X, automated server-health checks knocked a portion of Exchange Online infrastructure offline; engineers are now “deploying a targeted change to bypass this component” and have already begun restoring capacity on a subset of servers. What’s the ETA? In a status-dashboard post tagged incident EX1550543, Microsoft says the next progress update will arrive by 10:00 p.m. UTC (5:00 p.m. EST) and that full recovery is expected “later this evening” barring new findings. A spokesperson told Reuters the fix is rolling out region-by-region, prioritizing North American mailboxes first. Downdetector peaked at nearly 130,000 outage reports, but real-time graphs show error counts already trending downward as servers come back online. Users who still see “503” or “Something went wrong” messages are advised to: 1. Refresh Outlook on the web every 15–20 minutes; recovered clusters may accept new sessions sooner than mobile or desktop clients. 2. Toggle airplane mode on mobile devices to force a fresh connection path. 3. Use the Microsoft 365 Admin Center or status.cloud.microsoft.com for minute-by-minute health alerts if you manage an organization’s tenant. Why did Outlook go down? Microsoft’s preliminary root-cause analysis points to a faulty health-probe component misclassifying healthy servers as unhealthy, pulling them out of load balancers and overloading the remaining fleet. Engineers are hot-patching the probe logic and placing traffic caps on unaffected regions to stop domino failures. How long will Outlook be down? Based on prior incidents of similar scale—July 2025 (three-hour recovery) and March 2024 (four-hour recovery)—analysts expect inbox access to normalize within six hours of the first report, meaning most users should regain service before the U.S. West Coast workday ends. Stay tuned: we’ll update this story as soon as Microsoft confirms the all-clear signal. For now, keep an eye on the Microsoft 365 Status account and remember that emails sent during the window will queue and deliver automatically once the fix propagates.