A major Microsoft outage that began on Thursday, November 12, has left millions of people around the world unable to reliably use Outlook email, with knock-on problems in Teams, Copilot, SharePoint and other Microsoft 365 services. More than 15 hours later, Microsoft’s engineers are still fighting to restore full service, and the company has not given a time for complete recovery. Here’s everything we know: what went down, why, who was behind it, what Microsoft has said, and when it is likely to be fixed.
Quick answer: The outage started on November 12 (around late evening IST / early afternoon US Eastern time) when a large number of Microsoft’s Exchange Online servers unexpectedly went offline. Microsoft says it was not caused by a traffic surge or a cyberattack. Instead, a core process that sets up secure connections on the servers became overwhelmed, servers failed automated health checks and dropped out, and the remaining servers buckled under the load. Microsoft is reverting a recent network configuration change that coincided with the start of the problem. As of Friday morning (IST), recovery was only partial and no estimated time for full restoration had been given.
This is a developing story. Information is based on Microsoft’s service health updates and news reports up to about 12:30 PM IST on Friday, November 13, 2026.
What went down in the Microsoft outage
The heart of the problem is Exchange Online, the cloud service that runs Outlook email, calendars and mailboxes for businesses, schools and governments. Because so many Microsoft tools depend on it, the failure rippled outwards. Microsoft listed these services as affected:
| Service | What users saw |
|---|---|
| Outlook / Exchange Online | Couldn’t open mailboxes, send or receive email; calendars not loading |
| Microsoft Teams | Calendar and meeting features hit; core chat and calls mostly worked |
| Microsoft 365 Copilot | Features relying on email and calendar data failed |
| SharePoint Online | Shared mailboxes affected; direct file access largely worked |
| Planner, To Do, Intune | Listed as impacted by Microsoft |
| Microsoft Defender XDR, Defender for Office 365 | Listed as impacted by Microsoft |
Some users also couldn’t receive two-factor authentication codes by email, which locked them out of other services too.
How big is it?
- About 130,000 reports of Outlook problems were logged on Downdetector in the US shortly after 1 PM Eastern time on Thursday, according to the Associated Press. Those are complaints, not a count of affected users; the real number of people affected is far higher.
- Downdetector recorded disruption in 74 countries and territories, according to CGTN.
- Microsoft first said the issue was limited to the Americas, but soon warned it “may affect Microsoft 365 service connectivity for users in any region.”
- As the US went to sleep, the problems hit Australia and Asia during their working day on Friday. In Australia, businesses and government agencies said they were brought to a standstill.
- New York City Emergency Management warned of delays to emails and online city services, and told residents to call 311 or 911 for urgent needs.
Timeline of the Microsoft outage
| Time (IST) | What happened |
|---|---|
| Thu Nov 12, ~9:10 PM | A separate Teams incident in North America begins; Microsoft resolves it within about 90 minutes |
| Thu Nov 12, ~9:47 PM | Microsoft opens incident EX1550543 as users can’t reach Outlook mailboxes |
| Thu Nov 12, ~11:30 PM | Outlook reports on Downdetector spike to about 130,000 in the US |
| Thu Nov 12, ~11:37 PM | Microsoft warns users in any region may be affected |
| Thu Nov 12, ~11:56 PM | A wider incident, MO1550821, is opened for the rest of Microsoft 365 |
| Fri Nov 13, ~12:36 AM | Microsoft pauses all deployments and configuration changes |
| Fri Nov 13, ~12:48 AM | Microsoft says the load isn’t from extra traffic; servers are failing health checks and dropping out |
| Fri Nov 13, early morning | Some servers return after an alternative health check is used; Microsoft reports “limited recovery” |
| Fri Nov 13, ~5:50 AM | Microsoft warns restored servers “can become unresponsive again once they receive traffic” |
| Fri Nov 13, ~6:50 AM | Microsoft identifies an overwhelmed secure-connection process and starts reverting a recent network change |
| Fri Nov 13, ~9:00 AM | Microsoft says executive Charles Lamanna confirmed no sign of malicious or cyber activity |
| Fri Nov 13, ~9:40–10:30 AM | Partial recovery in some regions, but Microsoft says it isn’t “sustained”; it is scaling up capacity |
Times are converted from Microsoft’s UTC-stamped updates as reported by UC Today, ABC News and ABC Australia, and are approximate.
Why did Microsoft go down?
Microsoft has not published a final root cause yet, but its updates paint a fairly clear picture of what happened:
- Servers suddenly dropped out. A large number of Exchange Online servers became “unexpectedly unavailable.” Microsoft stressed that this was not caused by an increase in traffic; it was a loss of capacity.
- Health checks made it worse. Microsoft’s systems automatically test whether each server is healthy enough to take requests. Many servers failed these checks and were pulled out of service, so the remaining servers had to handle everyone’s connections.
- A core process was overwhelmed. On the affected servers, a process that establishes secure connections became overloaded and stopped handling requests, so even more servers stopped working. It became a vicious cycle.
- A recent network change is under suspicion. Microsoft says it is reverting a recent network configuration change whose timing matches the start of the outage. It hasn’t confirmed this change was the cause.
Think of it like a supermarket where half the checkout counters suddenly close. The queues at the remaining counters grow so long that those staff get overwhelmed too, and more counters shut. Even when Microsoft reopened “counters,” the waiting crowd rushed in at once and knocked them over again.
Who made it go down? Was it a cyberattack?
No, according to Microsoft and governments that have been briefed.
- Microsoft executive vice-president Charles Lamanna said there was no indication of malicious or cyber activity behind the outage.
- Microsoft said in its updates there was “no indication” the outage was caused by a cyberattack.
- In Australia, Home Affairs Minister Tony Burke said after a briefing that authorities “do not believe they are dealing with a cyber event.” The country’s National Cyber Security Coordinator, Lt Gen Michelle McGuinness, was monitoring the situation.
So, as things stand, no hacker or outside group caused this. It appears to be an internal infrastructure failure, possibly linked to a configuration change by Microsoft itself. A full post-incident review should confirm the exact trigger.
What Microsoft has said and done
Microsoft has posted regular updates on its Microsoft 365 Status account and service health dashboard. Its key statements and actions:
- It is “aggressively pursuing all pathways to reduce impact.”
- It paused all deployments and configuration changes so nothing new could make things worse.
- It moved traffic away from affected infrastructure and onto alternate routes.
- It restarted servers and used an alternative health check to bring some back online.
- It temporarily limited some types of traffic in certain locations to protect recovering servers.
- It is rebuilding some servers on a previous configuration and reverting the suspect network change.
- It admitted some fixes were “not taking as expected” and that restored servers kept becoming unresponsive once traffic returned. It also reported a surge of calls from routing services to backend servers, with some machines “stuck in a bad state.”
When will Microsoft be fully back?
Microsoft hasn’t given an ETA. As of Friday morning IST, both main incidents (EX1550543 and MO1550821) were still open, and recovery was partial and uneven. Teams chat and calls were mostly working, but Outlook, Exchange Online, calendars and Copilot were still impaired for many users.
Based on how these incidents usually go, the likely path is:
- Gradual recovery, region by region, as Microsoft rebuilds servers and slowly lets traffic back in so they don’t get overwhelmed again.
- A delay in emails arriving even after access returns, as queued messages are delivered.
- A preliminary post-incident report from Microsoft within a few days of the fix, with a fuller root-cause review later.
Treat any exact “fixed by” time you see on social media with caution until Microsoft confirms it.
What you can do right now
- Check the official status: the Microsoft 365 Status account on X, or status.cloud.microsoft. IT admins should follow EX1550543 and MO1550821 in the Microsoft 365 admin center.
- Try other ways in: some users had more luck with the Outlook mobile app or Outlook on the web than with the desktop app, or vice versa.
- Don’t keep reinstalling or resetting Outlook. The problem is on Microsoft’s side, not your device.
- Use a backup channel such as phone, WhatsApp or another email account for urgent messages, and let contacts know.
- Beware of scams. Fraudsters exploit outages with fake “Microsoft support” calls, messages and links. Never let anyone remotely access your device or share passwords or codes. Read our guide to common online scams.
Why this matters
This is the latest in a string of major cloud outages, and it shows how much of the world now runs on a handful of providers. When one Microsoft service fails, it can stall hospitals, governments, banks, schools and businesses across dozens of countries at once. Experts quoted by ABC Australia warned that even though big providers spread data across many locations, a single underlying flaw can still take everything down together. Microsoft’s AI assistant Copilot was hit too, a reminder that AI tools are only as reliable as the cloud underneath them. Learn more in how AI chatbots actually work.
Frequently asked questions
Is Microsoft down right now?
As of Friday morning IST, Microsoft 365 services, especially Outlook and Exchange Online, were still only partly working. Check Microsoft’s official status page for the latest.
Why is Outlook not working?
Many Exchange Online servers went offline after a core secure-connection process became overwhelmed and servers failed health checks, leaving too little capacity for everyone.
Was the Microsoft outage a cyberattack?
No. Microsoft and the Australian government say there is no sign of a cyberattack or malicious activity.
When will the Microsoft outage be fixed?
Microsoft hasn’t given a time for full recovery. Service is returning gradually and unevenly.
Will I lose my emails?
There’s no indication that data has been lost. Emails are expected to arrive, possibly late, once service recovers.
Sources: Microsoft 365 Status / Microsoft 365 service health (incidents EX1550543, MO1550821), Associated Press, ABC News (US), ABC News (Australia), CGTN, UC Today, CIO&Leader, Cybersecurity News.
