The Microsoft 365 outage that began on Thursday, November 12, 2026 knocked out Outlook email, Teams, SharePoint, Copilot and other Microsoft services for millions of people, and it was still not fully fixed on Friday morning. Microsoft says a group of servers kept failing automated health checks, which cut capacity and strained the rest of its system. So far, Microsoft has not confirmed a final root cause, and the sources we checked show no sign of a cyberattack. This guide explains what happened, who was hit, what Microsoft has said and what you can do right now.
Quick facts
- When it started: Thursday, November 12, 2026, with user reports spiking at about 12:39 p.m. ET.
- What broke: Exchange Online (Outlook email), Microsoft Teams, SharePoint Online, Microsoft Copilot 365, Microsoft Defender XDR, Microsoft Planner, Microsoft To Do, Microsoft Intune and Microsoft Defender for Office 365.
- How big: nearly 130,000 Outlook problem reports on Downdetector around 1 p.m. ET, and close to 150,000 combined reports in the US and Canada at the peak.
- Where: Microsoft first said the Americas, then warned that connectivity could be affected in any region. Users in India also reported problems on Friday morning.
- Cause so far: servers failing automated health checks and a core process on them being overwhelmed. Microsoft says it was not caused by extra traffic.
- Status: partial recovery on Thursday, but restored servers failed again under load. The outage stretched into Friday.
- Incident numbers: EX1550543 (Exchange Online) and MO1550821 (Microsoft 365).
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Timeline of the outage
| Time (ET) | What happened |
|---|---|
| Thursday, about 12:39 p.m. | Downdetector starts showing a spike in Outlook problems |
| 12:54 p.m. | Microsoft 365 Status says it is investigating users who cannot access Exchange Online mailboxes in the Americas |
| About 1:09 p.m. | More than 129,000 error reports are logged on Downdetector |
| 1:35 p.m. | Microsoft says the “elevated load” is not caused by more traffic but by a number of servers being unexpectedly unavailable, which strains the rest |
| Afternoon | Microsoft says affected servers are failing automated health checks and starts testing a workaround that bypasses the part that processes those checks |
| About 4 p.m. | Microsoft says it has restored some servers and is restarting others |
| Evening | Microsoft reports “positive results” and “partial recovery across regions,” but later says some planned fixes did not work as expected |
| Overnight | A core process on affected servers is found to be overwhelmed. Servers that came back later failed again under traffic |
| Friday morning | Services are still affected, and users in India and other regions report problems |
Times come from news reports and Microsoft’s status posts. Check Microsoft’s official status page for the latest.
What Microsoft has said about the cause
Here is the story in simple words:
- First guess: heavy load. Microsoft first said part of its system was “experiencing elevated load.”
- Then a correction. It said the load was not from extra traffic. Instead, a number of servers had become “unexpectedly unavailable,” which put more strain on the servers that were still running.
- Health checks failed. Servers are checked automatically to see if they are healthy enough to stay in service. Microsoft found that these checks were failing and taking servers out of service.
- A workaround helped, but only partly. An alternative method for the checks brought some servers back. But a returning server was not always able to handle a full load, and some failed again when traffic reached them.
- An overwhelmed process. Microsoft said a core process on affected servers was becoming overwhelmed, which caused a loss of capacity.
- Why it happened is still open. As of the reports we checked, Microsoft had not explained why the health checks failed or why processor use rose.
Was it a cyberattack?
Microsoft has not said so. A SecurityWeek report said Microsoft had not confirmed the root cause or shown evidence of a cyberattack, and that Microsoft’s advisories had not linked the outage to any security flaw. Treat any claim of an attack as unconfirmed until Microsoft or authorities say otherwise.
Who was affected
Everyday users. People could not open Outlook, send mail or log in to Microsoft apps. Both personal and work users reported problems.
Workplaces. Teams meetings, shared files in SharePoint, task tools such as Planner and To Do, and AI features in Copilot 365 were hit. Features that do not depend on Exchange Online kept working, according to Microsoft.
IT and security teams. The list of affected services included Defender XDR, Defender for Office 365 and Intune, which can reduce visibility and device management while the outage lasts.
Public services and transport.
- Hospitals in Canada said the outage affected some services. One said patient and resident care was not affected. Another, in Quebec, said appointment requests and some international operations were hit.
- Via Rail said passengers might not get emails about their trips.
- New York City’s emergency management office warned that people trying to email city agencies or use online city services that depend on Microsoft systems could see delays.
India. A report from The Statesman said users in India faced problems on Friday morning as the outage entered a second day. We did not find statements from Indian regulators or the government about this outage in the sources we checked. If you run IT for an Indian organisation, check your own service health dashboard.
What you can do right now
If you are a regular user
- Check Microsoft’s status first. Look at status.cloud.microsoft or the Microsoft 365 Status account on X before you spend an hour troubleshooting.
- Do not reset your password just because Outlook is down. The problem is on Microsoft’s side.
- Use another channel for urgent messages: phone, WhatsApp, SMS or another email account.
- Be patient and avoid refresh storms. Repeated retries can add load when services are recovering.
- Watch for scams. Criminals often send fake “outage fix” emails and texts during big outages. Do not click links or enter your password. See our guides on how to identify a fake text message and OTP scams in India.
If you manage IT for a company
- Open your Microsoft 365 admin center and follow incidents EX1550543 and MO1550821 for updates meant for admins.
- Tell your staff once, clearly: what is down, what still works and how to reach each other.
- Switch to backup communication, such as a company chat on another platform, a phone tree or a group messaging channel.
- Do not make big changes during the incident. Avoid changing mail flow, security policies or devices unless Microsoft tells you to.
- Expect delayed email. Mail may queue and arrive late. Warn customers that replies may be slow.
- Treat partial recovery as not stable yet. Microsoft reported servers that came back and then failed again.
- Keep a record. Note start and end times, affected users and business impact, so you can ask about service credits under your agreement.
- Review security visibility. If Defender tools were affected, check that logging and alerts are working again, and look for missed alerts once services return.
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Is this the first time?
Major cloud outages are not new, and Microsoft has had several:
- January 2026: reports said a Microsoft 365 outage in North America was linked to elevated service load and temporary capacity constraints during maintenance.
- October 2025: a large Microsoft outage affected Azure, Microsoft 365, Xbox and other services at the same time.
- July 2024: a faulty update from the security company CrowdStrike crashed Windows computers worldwide, disrupting airlines, banks and hospitals. That was a different cause, but it showed how a single failure can spread.
The pattern is clear: when so many companies depend on a few cloud providers, one failure can affect millions of people at once.
Lessons for businesses
- Have a backup way to communicate. Do not rely on one email and chat provider.
- Write an outage plan. List who decides, who tells staff and customers and what tools you use instead.
- Know your service agreement. Microsoft’s service terms include uptime promises and ways to request credits, so understand how to claim them.
- Reduce single points of failure. Keep critical contacts, documents and contracts available offline or in a second system.
- Practise. Run a short drill: “What if email and Teams are down for a day?”
- Mind your security. Outages are a good time for attackers to try phishing and social engineering.
For more on staying prepared, read our guides on ransomware risk for IT firms in India, the software supply chain attacks checklist and the best DDoS protection services.
What to watch next
- Whether Microsoft says the outage is fully resolved and when
- A detailed post-incident report with the root cause and why the health checks failed
- Whether service credits or compensation are offered to business customers
- Any statements from regulators or government bodies, including in India
- Whether this triggers a wider review of cloud resilience in companies and public services
FAQs
Is Microsoft 365 down right now?
As of Friday morning, November 13, 2026, reports said the outage that began on Thursday was still not fully fixed. Check Microsoft’s official status page or the Microsoft 365 Status account on X for the latest.
What caused the Microsoft outage?
Microsoft says a number of servers were failing automated health checks and becoming unavailable, and that a core process on those servers was being overwhelmed, causing capacity loss. It said the problem was not caused by extra traffic. A final root cause has not been published in the reports we checked.
Was the Microsoft outage a cyberattack?
Microsoft has not said it was. A SecurityWeek report said Microsoft had not confirmed the root cause or shown evidence of a cyberattack. Treat attack claims as unconfirmed.
Which Microsoft services were affected?
Microsoft listed Exchange Online (Outlook email), Teams, SharePoint Online, Copilot 365, Defender XDR, Planner, To Do, Intune and Defender for Office 365. Parts of these services that do not depend on Exchange Online kept working.
Was India affected by the Microsoft outage?
Yes, some users in India reported problems on Friday morning, according to The Statesman. Microsoft also said connectivity could be affected in any region, not only North America.
How many people were affected?
Downdetector showed nearly 130,000 reports for Outlook around 1 p.m. ET on Thursday, and close to 150,000 combined reports for the US and Canada at the peak. These numbers count reports, not the total number of users affected.
When will Microsoft Outlook be back?
Microsoft had not given a fixed time. It reported partial recovery on Thursday, but some restored servers failed again. Follow the official status page for updates.
What should I do if Outlook is not working?
Check Microsoft’s status page first, avoid resetting your password, use another way to reach people for urgent matters and wait for recovery. Do not click links in emails or texts that claim to fix the outage.
Is my data lost?
No report we checked said data was lost. Microsoft described an availability problem, which means people could not reach services. Mail may arrive late. Check Microsoft’s final incident report for details.
Can businesses claim compensation?
Business customers may be eligible for service credits under Microsoft’s service level agreement if uptime targets were missed. Check your agreement, keep records of the impact and follow Microsoft’s claim process.
Is Copilot affected too?
Yes. Microsoft Copilot 365 was on the list of affected services, because many of its features depend on Exchange Online and other Microsoft 365 components.
How can I check if Microsoft is down?
Use Microsoft’s official service status page, the Microsoft 365 Status account on X and, for admins, the service health page in the Microsoft 365 admin center. Outage trackers such as Downdetector show user reports.
Has this happened before?
Yes. Reports mention a Microsoft 365 outage in January 2026 linked to capacity problems during maintenance, a large multi-service outage in October 2025 and the CrowdStrike-related global outage in July 2024.
Final thoughts
Outages like this are frustrating, but they teach a useful lesson: even the biggest cloud services can fail, and the best protection is a calm backup plan. Check official sources, avoid panic fixes, watch out for scams and keep a second way to reach your team and customers. We will update this article as Microsoft shares the full cause and the final fix.
Your next step: Join the Infovistar WhatsApp channel for fast updates, read our guide to ransomware risk for IT firms and contact us if your business needs help planning for outages.
This is a developing story. Facts come from news reports and Microsoft’s public status posts as of the morning of November 13, 2026, and may change. Confirm details on Microsoft’s official status page.
