Ing. Calogero Bono
Since Thursday afternoon, Microsoft 365 has not been working for millions of users around the world. The outage affects Exchange Online, the service that handles email and calendars, and it takes Outlook down with it, along with the Teams and Copilot features that depend on email. After more than twelve hours, Microsoft has not yet said when everything will be back to normal. It matters because it shows how much a company can depend on a single cloud provider.
A few terms before we get into the facts. Exchange Online is Microsoft's service that hosts mailboxes and calendars. Health checks are the automated tests the system uses to decide whether a server is able to work. Downdetector is a portal that collects user reports of service disruptions. Post-Incident Report is the report with the cause and the fixes that Microsoft promises once the problem is resolved.
What is happening to Microsoft 365?
According to The Register, the outage began on Thursday around 18:00 UTC. Users cannot access email, join Teams meetings, or use cloud PCs and Copilot. Another 15 hosted services are also involved.
Microsoft says the problem affects services that interact with Exchange Online and email. Those that do not depend on it remain operational. DDay notes that Teams calls, meetings and chats remain largely usable.
What is the cause of the outage?
The cause has not been confirmed. Microsoft has spoken of servers failing automatic health checks and becoming unavailable. The work has focused on the remaining machines, which went into overload. Microsoft clarifies that the number of connected users has not increased, but capacity has dropped.
Overnight, restarted servers were locking up as soon as they received traffic. The company also reported a spike in internal requests, partly caused by its own attempts to redistribute the load. According to some press sources cited by DDay, Microsoft is reportedly rolling back a recent network configuration change, but it has not confirmed that this is the cause.
Is it a cyberattack?
Microsoft says no, or rather that it is not aware of one. As The Register reports, at 04:11 UTC it spoke of "no indication that this is the result of malicious activity", then at 05:46 UTC it wrote that it was not aware of any malicious activity behind the incident. The tone changed, but the substance did not.
CNN reports that a Microsoft executive ruled out a security breach. Banks, however, are urging customers to beware of scams and phishing, because criminals can take advantage of the disruption.
Who is being affected?
According to CNN, Downdetector reports reached 74 countries and territories within about an hour. Banks, governments and courts have been hit. In the United States several local authorities cannot send or receive email, and one company postponed its quarterly results presentation. In Japan some public services have switched to paper.
Several airlines reported problems with email customer support, with no effect on flights. The outage also hit the connectors through which the assistants of OpenAI and Anthropic access Microsoft 365 data. Punto Informatico reports a sharp rise in reports from Italy on the morning of November 13.
To go deeper, Microsoft, November 2026 Patch Tuesday with over 1,000 flaws and a zero-day in Outlook and Windows 11 KB5132061, the November update does not install on some PCs and Microsoft fixes it.
Limits to know
The confirmed cause and the recovery times are still missing. The network change is only a rumor from the press. We do not know how many users are really affected, because Downdetector numbers measure reports, not users. The Post-Incident Report promised by Microsoft will only arrive once the problem is mitigated, and it could change the picture.
What changes for those working in digital
For anyone working in digital, the first effect is practical. If email sits in the cloud of a single provider, when it stops everything stops, including notifications from management software and customer confirmations. It is worth having an alternative channel to communicate with clients and teams, and knowing who activates it. Those who use Microsoft 365 should also remind employees not to click on messages offering help with the outage. If you are evaluating the platform, you can reread our comparison between Google Workspace and Microsoft 365.
Our take
An outage of more than twelve hours on a service this widespread is not just a technical problem. What stands out is that the attempts to fix it made the load worse, as Microsoft itself admits. It is a sign of very complex systems, where the correction can become part of the problem. The answer is not to abandon the cloud, but to stop treating it as infallible infrastructure. Whoever manages a company's email should have a written plan for the days when it is not available. The European debate on technological sovereignty, raised by CNN, also runs through here.
Frequently asked questions
Why is Outlook not working?
Because Exchange Online, the service that handles email, has capacity problems. Many servers stopped passing health checks and were excluded. The machines left running went into overload.
Is Teams down?
Only partly. Calls, meetings and chats remain largely usable, according to DDay. The features that depend on email, however, are affected, and The Register also reports meetings that cannot be reached.
Was it a hacker attack?
Microsoft says it is not aware of any malicious activity. One of its executives ruled out a security breach. We will have to wait for the final report for full confirmation.
When will everything be back to normal?
No time has been announced. Microsoft first reported marginal success and then positive results on stability and capacity. Full recovery still has no date.
Should I worry about scams these days?
Yes, it is wise to be careful. Several banks warn that criminals may take advantage of the outage. Do not click links from unknown senders and never share passwords or one-time codes.
What to watch for when Microsoft publishes the outage report
The real clarification will come with the Post-Incident Report. Until then, many of the hypotheses remain hypotheses.
- Read Microsoft's final report and check whether it confirms the network change as the cause.
- Check your Microsoft 365 contract to see whether refunds or credits are provided for the outage.
- Watch whether European institutions revive the technological sovereignty debate after this episode.
