Microsoft has suffered a major global outage, disrupting several widely used digital services, including Outlook, Microsoft Teams and cloud storage platforms. The disruption has affected individuals, businesses, schools and government services across different parts of the world.

According to outage-tracking website DownDetector, around 130,000 users reported problems accessing Microsoft Outlook by early Thursday afternoon US Eastern time, corresponding to early Friday morning in Sydney.

In a statement posted on X, Microsoft said it was working urgently to minimise the disruption and restore affected servers. The company also confirmed that it was restarting servers to bring services back online.

The incident highlights how failures in shared digital infrastructure can disrupt multiple services simultaneously, even when those services appear to operate independently.

More Than Just Emails and Online Meetings

The outage has affected a wide range of Microsoft's products and services, including:

  • Microsoft Outlook

  • Microsoft Teams

  • SharePoint Online

  • Microsoft 365 Copilot

  • Microsoft Planner

  • Microsoft Exchange Online

  • Microsoft Defender

The consequences have extended beyond routine workplace disruptions. Reports indicate that family violence support workers have been unable to access important client databases, while some schools have struggled to provide online lessons.

Psychologists have also faced difficulties delivering telehealth consultations. Meanwhile, businesses have experienced problems processing orders, job seekers have missed planned interviews, and some government service centres have been forced to close.

The disruption has also affected services outside Microsoft's ecosystem. OpenAI and Anthropic reported problems with tools connecting their AI services to Microsoft 365.

What Caused the Microsoft Outage?

Microsoft has yet to establish a definitive root cause of the global disruption, but its initial updates have pointed towards problems involving server availability and automated monitoring systems.

Initially, the company reported unusually high workloads across multiple regions. However, it later clarified that the issue was not caused by increased internet traffic. Instead, a large number of servers had unexpectedly become unavailable.

Investigations then focused on Microsoft's automated server health-check systems, which determine whether individual servers are functioning properly and can safely handle incoming traffic.

According to Microsoft, a critical process running on affected servers became overwhelmed. The company subsequently paused software deployments and configuration changes while reviewing recent updates.

However, it did not identify any recent changes directly responsible for triggering the incident.

Was Microsoft Hit by a Cyberattack?

Despite the scale of the disruption, Microsoft has said there is no indication that the outage resulted from a cyberattack.

A distributed denial-of-service (DDoS) attack typically involves overwhelming a service with excessive external requests, preventing legitimate users from accessing it.

However, Microsoft's statement that overall traffic had not increased does not support that explanation. The company has also disclosed no evidence of malicious activity.

A possible explanation is that Microsoft's automated health-check system malfunctioned, causing operational servers to be incorrectly marked as unhealthy and removed from service.

This could have placed additional pressure on the remaining servers, creating a chain reaction that made the disruption worse. However, the precise cause remains unconfirmed pending a full investigation.

Microsoft Services Still Facing Recovery Challenges

Microsoft has confirmed that some affected servers have returned to operation. However, the recovery process has not been completely smooth.

The company warned that certain servers could become unresponsive again when they begin receiving traffic.

This is not the first major disruption to Microsoft's services this year. Outlook, Teams and other Microsoft 365 services experienced outages in January, while another disruption in August affected Outlook and Exchange Online following a software code update.