Microsoft 365 Outage: Outlook, Teams and Copilot Hit in 74 Countries

On Thursday, November 12, a Microsoft 365 outage, the subscription suite that includes Outlook and Teams, prevented access to email and other services in 74 countries and territories, according to the monitoring site Downdetector.¹²³ Microsoft attributed the problem to infrastructure under strain, and by the evening it was reporting a recovery that was still limited, without saying when services would return to normal.⁴²

Which services were affected

In the Microsoft 365 admin center notice, identified by the code MO1550821, the company listed as affected Exchange Online (the email service), Teams, SharePoint Online, Microsoft 365 Copilot and Microsoft Defender XDR.⁴ Around 5 p.m. Eastern Time (ET) in the United States, Planner, To Do, Intune, Defender for Office 365 and Purview were added to the list, while problems were also reported for Power BI and the Microsoft 365 app admin center.⁵ The notice concerned the Business and Enterprise tiers, but according to Engadget individual users were also affected.⁵ Microsoft explained that the functions of various services that depend on Exchange Online were compromised, while those that do not interact with email continued to work.⁶

How many users were involved

The disruption became global within about an hour. The map published by Downdetector showed users affected in the Americas and in parts of Europe, Asia and Africa.³ In the United States, about 130,000 users reported problems with Outlook shortly after 1 p.m. ET. By 6 p.m. the reports had fallen to about 37,000, again according to Downdetector.³ The estimates reported for the number of people affected worldwide range from tens of thousands to millions. Downdetector collects reports sent by users, so its figures measure reports, not the actual number of people without service.⁴²³

What Microsoft said about the cause

Microsoft first pointed to a heavy load on the infrastructure in several regions, then clarified that this load did not come from a rise in traffic but from a series of servers that unexpectedly became unavailable, overloading the remaining ones.⁵⁴ A later update explained that a central process on the affected servers was being overloaded, causing them to stop responding and reducing overall capacity. SecurityWeek reports that the servers’ health checks were failing and that Microsoft did not indicate any evidence of a cyberattack.⁵⁶ The company said it had paused all rollouts, redistributed connection traffic across its global infrastructure, moved other traffic away from the affected systems and restarted the servers involved. It also evaluated whether to roll back some recent configuration changes to speed up recovery.⁴³ According to Microsoft, the incident began on Thursday at 1:26 p.m. ET, although the company had already been investigating connection problems to Exchange Online mailboxes in the Americas before that.⁴ A separate Teams incident, tracked as TM1550488, had affected North and South America between 9:45 and 10:53 ET, with delays or errors in sending and retrieving messages. Microsoft attributed it to resource contention in the infrastructure and marked it as resolved, without saying whether the two episodes are connected.⁴

Where the recovery stands

At 6:57 p.m. ET, Microsoft announced on X that it had returned some servers, which were now stable, to service and that it was seeing limited recovery by shifting traffic onto alternative paths. It warned that the return to normal would be gradual, as customer applications reconnect.⁴³ According to SRF’s account, the attempts went in fits and starts. Microsoft reported that servers brought back online could freeze again as soon as they received traffic, then spoke of positive results after restarting parts of the infrastructure in isolation, and finally admitted that the measures were not working as expected.⁷ Exchange Online, under the code EX1550543, and the overall incident MO1550821 still appeared as open on the service health dashboard.⁶

The effects outside the United States

In Australia, where the problem had been reported from around 5 a.m. on Friday (Australian Eastern Time), the Guardian reported that schools, courts and public services were left without email and online meetings. The Western Australian executive said the federal government was working with Microsoft at the highest levels and that the company was prioritizing life, safety and government services.⁸⁹ The Australian Medical Association had not received reports of hospitals or clinics being affected, and the impact mainly concerned sending and receiving email.⁸

Why it matters

SRF recalls that Microsoft’s email services had already suffered an outage of several hours at the end of August, which Microsoft had attributed to a problem in the cloud infrastructure.⁷

Was the Microsoft 365 outage caused by a cyberattack?

Microsoft spoke of servers that had become unavailable and of an overloaded central process, and according to SecurityWeek it did not indicate any evidence of a cyberattack. The company was still investigating the cause.⁴⁶

This article was written by artificial intelligence from the sources cited, without human review. Automatic newsroom by Redazia.

Sources

Footnotes

1. Caída de Microsoft hoy, 12 de noviembre: Outlook, Teams y 365 presentan fallas a nivel mundial, ¿cuándo vuelven?, El Comercio (Perú), 2026-11-12 ↩

2. Major Microsoft Outlook outage disrupts services in 74 countries, France 24, 2026-11-13 ↩ ↩² ↩³

3. Microsoft Outlook and Teams face global outage, impacting millions across 74 countries, Gulf News, 2026-11-13 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

4. Massive Microsoft 365 outage disrupts Outlook, Teams, Copilot worldwide, BleepingComputer, 2026-11-12 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

5. Multiple Microsoft 365 services are experiencing an outage, Engadget, 2026-11-12 ↩ ↩² ↩³ ↩⁴

6. Microsoft 365 Outage Disrupts Outlook, Exchange Online and Teams, SecurityWeek, 2026-11-12 ↩ ↩² ↩³ ↩⁴

7. Software-Riese Microsoft – Stundenlanger Ausfall beeinträchtigt Outlook und Teams, SRF News, 2026-11-13 ↩ ↩²

8. Microsoft outage live: Microsoft prioritising ‘life, safety and government services’ as global outage wreaks havoc for Outlook users, Latest news, sport and opinion from the Guardian, 2026-11-13 ↩ ↩²

9. ‘Looks like we’ll have to talk to people’: Australia sent back to time before email with major Microsoft outage, The Guardian · World, 2026-11-13 ↩