A Microsoft outage disrupted Outlook and Teams worldwide for over 12 hours. Early signs of recovery are emerging.
A massive outage hit more than a dozen Microsoft cloud services, including Outlook email and Teams messaging, and stretched into Friday as the company struggled to restore them. Microsoft began warning users on social media around 12:50 p.m. ET Thursday that it was investigating problems accessing Exchange Online, its cloud email service. Within about an hour, Downdetector had logged reports from 74 countries and territories.
Downdetector recorded more than 130,000 Outlook problem reports around 1:27 p.m. ET Thursday, along with more than 46,000 for Microsoft 365. By about 07:00 GMT Friday, it still had at least 43,000 Outlook reports from users in 72 countries. Microsoft listed Exchange Online, Teams, SharePoint Online, Copilot 365 and Defender XDR as affected. Its consumer products, including Outlook.com and OneDrive, were also hit.
Microsoft said the connectivity problems stemmed from elevated load across multiple regions, after a number of servers became unexpectedly unavailable and strained the remaining infrastructure. A Microsoft executive confirmed the outage was not the result of a security breach. Amazon Web Services said it was operating normally.
At 4 p.m. ET Thursday, Microsoft said an alternative service health check method had brought some affected servers back online. More than 12 hours in, the company reported only “marginal success,” and it extended the email timeout window to 48 hours. At about 2:30 a.m. ET Friday, it reported positive results after applying a patch to an upstream authentication and routing configuration component on part of its infrastructure. It later cited early stabilization and capacity improvements, while saying recovery work was still ongoing.
Outlook is central to the daily work of governments, schools and businesses around the world, and Microsoft has about 450 million users. Experts said the outage shows the risks of companies relying on a handful of tech giants. Microsoft gave no timeline for full restoration and referred users to its health dashboard for accurate data.
This report draws on NBC News, CNBC, CNN, Al Jazeera, TechRepublic (citing Reuters), TechRadar and ABC News.