The story in brief
- 1Microsoft 365, including Outlook, Teams and Copilot, went down on 12 November 2026 and was disrupted for nearly a day, with about 140,000 reports from 74 countries on Downdetector.
- 2Microsoft says settings applied to servers after an update overwhelmed a process that sets up secure connections, so servers stopped responding; it began rolling back a recent network configuration change.
- 3Microsoft said it was not a cyberattack and not caused by AI agents, and apologised after almost 24 hours of disruption. The final root-cause report is still pending.
- 4The outage followed the November Patch Tuesday that fixed 1,094 vulnerabilities, but Microsoft has not confirmed a link.
- 5The lesson for a business is not to panic but to plan: a second way to reach customers and staff, local backups of critical files, and tools that keep working when the cloud is down.
Microsoft 365, including Outlook, Teams and Copilot, went down on 12 November 2026 and stayed disrupted for nearly a day, with about 140,000 reports from 74 countries. Microsoft says a settings change applied after an update, not a cyberattack, was behind it. For a business, the takeaway is not to switch away from Microsoft but to have a plan for the day your main tool is unavailable.
What happened
According to the Wikipedia record of the 2026 Microsoft outage and TechRadar's live coverage:
- When: it began around 17:00–18:00 UTC on 12 November 2026 and continued into 13 November. Microsoft reported partial recovery at 4:36 GMT on 13 November, with email queues approaching normal that afternoon.
- What broke: Microsoft 365, mostly narrowed to Exchange Online, which powers email and Outlook, along with Teams and Copilot.
- How widespread: about 140,000 people from 74 countries reported problems on Downdetector by the evening of 12 November.
- Microsoft's timeline: it acknowledged the Exchange Online problem in the Americas at 17:54 GMT, warned of broader global problems at 18:07 GMT, and said it was "deeply sorry" after almost 24 hours of disruption.
Why it happened
Microsoft says settings applied to its servers after an update overwhelmed a process that establishes secure connections, so the servers stopped handling requests and capacity fell. It began rolling back a recent network configuration change that correlated with the start of the impact. Importantly, Microsoft said the outage was not a cyberattack and not caused by AI agents. The outage came days after the November Patch Tuesday that fixed 1,094 vulnerabilities, which we covered in our Patch Tuesday report, but Microsoft has not confirmed any link. The final root-cause report is still pending, so treat the configuration-change explanation as Microsoft's preliminary finding, not the last word.
What it means for businesses
If your email, meetings and files all live in one provider, an outage like this stops the whole office at once. The answer is not to abandon Microsoft 365, which is reliable the vast majority of the time, but to plan for the rare bad day.
- Have a second way to reach people. If Outlook is down, how do you tell staff and customers? A WhatsApp broadcast, a phone tree or a second email on a different domain keeps you reachable.
- Keep local backups of what you cannot work without. Today's quotes, today's orders, key contracts. A cloud outage is also a reminder that your data should exist in more than one place. See our note on Microsoft 365 for small businesses.
- Prefer tools that keep working offline. A point-of-sale or ordering system that keeps serving when the internet or a cloud service drops is worth more than one that simply stops. We built one for exactly this reason: our guide to an offline restaurant POS.
- Know your provider's status page. Microsoft posts incidents in the admin centre (this one was EX1550543 and MO1550821). Knowing where to look saves an hour of guessing whether it is you or them.
- Ask your IT provider the plan. "What do we do, step by step, when Microsoft 365 is down for a day?" is a fair question. If there is no answer, that is the gap to fix.
An outage is not a reason to panic or to blame your own setup. It is a prompt to check that one provider having a bad day cannot take your whole business offline with it.
We help businesses set up Microsoft 365, backups and a continuity plan through our IT support and cloud services. Tell us what your office relies on and we will help you work out the fallback.
Sources
Frequently asked questions
On 12 November 2026 Microsoft 365 services, including Outlook, Teams and Copilot, began failing, starting with Exchange Online in the Americas and spreading worldwide. About 140,000 people in 74 countries reported problems on Downdetector. Microsoft reported partial recovery the next day, with email queues approaching normal by the afternoon of 13 November.
Microsoft says settings applied to its servers after an update overwhelmed a process that establishes secure connections, so the servers stopped handling requests and capacity dropped. It began rolling back a recent network configuration change that correlated with the start of the impact. The final post-incident report is still pending.
Microsoft said the outage was not caused by a cyberattack and not caused by AI agents. It apologised after almost 24 hours of disruption.
You cannot stop a provider outage, but you can plan for it: keep a second way to reach customers and staff (a phone, WhatsApp or a second email domain), keep local backups of files you cannot work without, use tools that keep working offline, and ask your IT provider what the plan is when a core service is down.
Related services
Get new articles by email
How we build automation and software, with the lessons learned. One short email when a new article goes up. No spam.
- #Microsoft 365
- #Outage
- #Outlook
- #Cloud
- #Business Continuity
- #IT Support
