> Microsoft 365 outage: What you can do about it

Businesses around the world are continuing to struggle with a Microsoft 365 outage that has taken down Outlook, Microsoft’s flagship email service. It also disrupted a long list of services that depend on Exchange Online. More than 10 hours after the first reports, Microsoft still hadn’t announced a full fix. Here’s what happened, what Microsoft has said about the cause, who was affected, and what to watch out for as services come back online. When the outage started Users began reporting problems around 12:30 PM Eastern Time on Thursday. Microsoft’s first status update said users were “experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas.” It later warned that the problem could affect customers “in any region.” Outlook problem reports on Downdetector peaked around 130,000, while services like Microsoft Teams, Microsoft OneDrive, and Copilot Chat also generated outage reports that grew into the thousands. Business Standard said that users in 74 countries had reported disruptions. Which services were affected Outlook took the hardest hit. People couldn’t open their mailboxes on the web, desktop, or mobile apps, and emails arrived late. But so much of Microsoft 365 relies on Exchange Online that the problems went well beyond email. Business Standard reported problems with Copilot Chat, Planner, To Do, Defender, Purview, Microsoft Graph, Fabric, Power BI, SharePoint Online, Universal Print, Windows 365, and some Intune functions. Some users couldn’t open recently used files, and parts of the Microsoft 365 admin center wouldn’t load. Microsoft 365 Education tools were also affected. Teams messaging and meetings mostly kept working, though calendars and meeting scheduling were disrupted. Features that don’t depend on Exchange Online reportedly kept running. What caused it Microsoft hasn’t published a full root cause. Its updates describe a chain of infrastructure failures rather than a single event. Microsoft said “a core process on affected servers is becoming overwhelmed,” which stopped those servers from processing requests, according to its 365 status account on X. Some servers then failed automated health checks and were taken out of service, which pushed more load onto the servers that were left. Microsoft said the extra load came from “a number of servers being unexpectedly unavailable,” not from more traffic. In a post on X, Microsoft Executive Vice President Charles Lamanna said that a security breach wasn’t the cause. He also said there was “no indication” of “malicious” activity. Watch out for scammers Even if the outage itself is not the result of an attack, these events do attract opportunistic actors trying to capitalize on the confusion and people’s desperation to get back to work. In previous cases, phishing scammers have been known to send out fake password-reset messages as services come back, trying to trick people into handing over their credentials and access to their services. Don’t fall for it. Microsoft doesn’t need you to reset your password. It just needs your patience as it tries to get back on track. Why it matters This comes after another major Microsoft 365 outage in January, which took 10 hours to sort out. Other providers have also experienced downtime in recent years, including Gmail and Proton Mail, although those incidents were resolved in a few hours, at most. Many organizations run email, calendars, files, chat, and security tools through one provider. When that provider goes down, it can take most of the working day with it. Business leaders already worry about this risk. In a Proton survey of 1,500 business leaders in the UK, Germany, and France, 54% said they couldn’t continue operations for more than one business day without access, and only 34% had a fallback for email. The same survey found that 74% worry a US kill switch could disrupt their operations. That’s a different trigger with the same result: losing access to the tools your business runs on. Planning ahead helps. Proton’s business continuity solution sets up backup email and communication tools in advance, using the email addresses your team already has, so you stay reachable when your main workspace fails. For organizations rethinking how much they rely on one provider, Proton Workspace is a secure and private Microsoft 365 alternative.