More than 430 million Microsoft 365 users face severe disruptions as a global software outage impacts Outlook, Teams, and Copilot across at least 74 countries.
The technical failure began on Thursday afternoon at 17.15 Dutch time, according to US. Users worldwide lost access to email inboxes, calendar functions, and online meeting tools in an incident that Downdetector recorded generating nearly 140,000 peak complaints, NRC reported.
Microsoft attributed the crisis to a spike in infrastructure load caused by unexpected server availability drops. A Microsoft executive said that the incident does not stem from a cyberattack or security breach, according to NRC.
‼️Update: Microsoft confirmed that its recent fixes haven't worked as expected. Engineers are exploring other ways to increase capacity and address ongoing traffic imbalances. Administrators can track updates in the Microsoft 365 admin center under EX1550543 and MO1550821.… https://t.co/4E4c8fxo7S
Corporate networks, government agencies, educational institutions, and media organizations like RTV Utrecht experienced immediate operational hurdles. OpenAI and Anthropic also reported disruptions in their integrations with Microsoft services, as noted by NRC.
Engineers attempt to stabilize server architecture through traffic adjustments
Microsoft engineers attempted to reboot failed servers and route data traffic through alternative pathways overnight. Those initial mitigation steps failed to deliver expected results, leaving systems unstable through Friday morning.
🔻 Massive Microsoft 365 Outage Impacts Outlook, Teams, SharePoint, Copilot, & Defender XDR users Details: https://t.co/pVFe4mMkw1 A major Microsoft 365 outage disrupted cloud service access on November 12 and continued into November 13, 2026, as Microsoft worked to restore… pic.twitter.com/4ENzplqsw7
Company representatives reported partial recoveries in targeted regions after implementing traffic adjustments. Engineers continue investigating additional measures to stabilize the broader server architecture.
“We are seeing a partial recovery in the regions where we have implemented these adjustments,” Microsoft said in an update shared by Broadcasting Brabant.
We're investigating reports of users experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas. More details can be found in the Microsoft 365 admin center under EX1550543.
Tech analysts warn that if the disruption reaches the 24-hour mark, it will rank among the heaviest outages in the platform’s history. Corporate productivity losses are expected to mount into the billions of dollars globally.
Operational Adjustments and Security Risks
Companies relying on Microsoft 365 have had to pivot toward alternative communication channels. Broadcasters such as Broadcasting Brabant established direct lines via WhatsApp and telephone to maintain news delivery.
IT experts advise organisations to exercise caution regarding phishing attempts during the outage. Bad actors might exploit communication gaps by using external email services to impersonate regular business contacts, Dutchcowboys warned.
Internal communication policies also face stress tests as teams consider third-party tools like Zoom or Google Meet. Security protocols often prohibit sharing corporate data on unauthorized consumer platforms.
We’re continuing our efforts to improve server stability to improve traffic flow. This includes adjusting traffic protocols, redistributing traffic, and applying strategic traffic blocking measures. We're observing partial recovery across regions in which we've applied these…
Frequently Asked Questions
Which specific Microsoft services are failing?
Exchange Online-dependent features such as Outlook email, Microsoft Teams meetings, and the Copilot AI assistant are primarily affected. Other independent modules within the Microsoft 365 suite continue to operate normally, according to NRC.
How many countries are experiencing downtime?
At least 74 countries and territories across West Europe, the Americas, Australia, and India registered system failures. Downdetector logged tens of thousands of complaints globally on both Thursday and Friday.
What is causing the server failures?
Microsoft said that unexpected server unavailability placed intense pressure on the remaining cloud infrastructure. The company explicitly ruled out any malicious cyber activity or hacker involvement.
How can people reach affected news organizations?
Outlets like Broadcasting Brabant established alternative communication channels including phone lines and messaging apps such as WhatsApp to bypass crippled corporate email servers.
Earlier coverage: Microsoft Outage Disrupts Outlook, Teams, and Microsoft 365 Services Globally
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