Sorry, Margaret, your email is working again.
After a widespread outage shut down Microsoft 365 services for businesses, governments, and tens of millions of other users around the world, the essential cloud services are now (mostly) back online, according to the company’s status page.
The outage debacle began around lunchtime on the East Coast on Thursday, with users reporting Outlook outages to the service-tracking website Downdetector just after 12 pm ET. Within the hour, Microsoft said it was investigating reports of an outage that at the time was limited to North America. It quickly spread to impact more than 70 countries around the world.
The full cause of Microsoft’s unprecedented outage remains unknown, but the company repeatedly ruled out a cyberattack as the cause in statements to its status page. It is also ruling out AI or AI agents playing a role in the debacle.
“We are seeing broad recovery and stability across our services,” a Microsoft spokesperson says in a statement. “This was a technical issue not related to cyber or AI/agents. The incident was introduced by an issue during an earlier network capacity upgrade that surfaced following a recent network change. We have addressed the underlying issue and continue to restore service to remaining customers and regions.”
The company has promised a “full post-incident report” after it has fully reviewed what went wrong.
As Outlook, Teams, Copilot, and other Microsoft 365 systems come back online, users will likely see their inboxes turn into a mess. “You’re probably going to get a lot of notifications when things come back,” says Jonathan Leitschuh, an independent researcher.
Microsoft said it had increased the queue time for emails to 48 hours in an attempt to ensure that every message that people tried to send while its systems were down gets delivered. Leitschuh points out that, even with the bulk of systems restored, users may receive “a flood of notifications a few hours down the pike” as subsystems come back online.
The total impact of the Microsoft outage may never be fully known, but it’s safe to say it’s already significant. Governments from Japan to the United States reported disruptions to a bevy of functions. Airlines reported problems with their ability to communicate with customers. Many law enforcement and emergency services ground to a halt. And hospitals reported widespread interruptions to their operations.
Ultimately, the episode serves as a reminder of the risks involved when the whole world relies on a single company for a critical service. “We’re very interdependent on these systems in modern life,” says Leitschuh. Next time, delayed emails may be the least of our worries.