Businesses around the world spent a day struggling with a major outage that took down Outlook, Microsoft’s flagship email service. The outage disrupted access to email and other Microsoft 365 services that depend on Exchange Online.
So, is Outlook still down? Nearly a full day after the first reports, Microsoft announced that email volumes were “approaching normal levels.” 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 did the Microsoft outage start?
Users began reporting problems around 12:30 PM Eastern Time on Thursday. Microsoft’s first status update(new window) 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(new window) had reported disruptions.
Which services are 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.
The Outlook issues were part of a wider disruption affecting Microsoft’s cloud infrastructure. While the email outage prevented many users from accessing their inboxes, other Microsoft 365 applications also experienced interruptions.
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.
Why is Outlook down?
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(new window). 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(new window) that a security breach wasn’t the cause. He also said there was “no indication” of “malicious” activity.
What to watch out for
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.
What the outage means for businesses
This comes after another major Microsoft 365 outage in January(new window), which took 10 hours to sort out. Other providers have also experienced downtime in recent years, including Gmail(new window) and Proton Mail, although those incidents were resolved in a few hours, at most.
The latest Microsoft issues highlight how dependent businesses have become on a single provider for essential communication and productivity tools. When Microsoft experiences an outage, disruptions can extend well beyond email.
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.
FAQ
Is Outlook still down?
The Microsoft outage has disrupted access to Outlook for users across multiple regions. Check Microsoft’s official service status updates for the latest information on service restoration.
Why is Outlook down?
Microsoft has attributed the disruption to infrastructure issues affecting Exchange Online servers. These issues prevented some servers from processing requests, disrupting access to Outlook mailboxes.
Is Microsoft Teams down too?
Microsoft Teams was also affected by the wider Microsoft 365 disruption. However, messaging and meetings largely continued working, while some connected features, including calendars and scheduling, experienced problems.
What should I do during a Microsoft email outage?
Businesses should monitor Microsoft’s official service updates, avoid suspicious password-reset messages, and use established backup communication channels until services are restored.
