Microsoft has confirmed that the major Microsoft 365 outage, which disrupted Outlook, Teams and Copilot services for more than 24 hours across at least 74 countries, has been resolved.

In its final status update, the company said it had completed efforts to address the underlying technical issue and restored services.

The widespread disruption affected businesses, government offices, hospitals and airlines, forcing many organisations to rely on alternative communication methods, including phone calls, paper records and even fax machines.

The outage began on November 12, when users in the Americas reported difficulties accessing their Exchange Online mailboxes. Microsoft acknowledged the issue at 5:54 pm GMT (11:24 pm IST) and subsequently warned that users across other regions could also face disruptions.

Microsoft Blames Network Upgrade For Outage

Microsoft attributed the disruption to a technical issue linked to an earlier network capacity upgrade.

According to a company spokesperson, the problem surfaced following a recent network change. Microsoft clarified that the incident was not related to a cyberattack or artificial intelligence (AI) agents.

Also Read:Microsoft global outage: Thousands affected as Outlook, Teams & 365 services face disruption

Initially, the company cited elevated network load across several regions as the possible cause. However, further investigation revealed that traffic levels had not increased.

Instead, several servers unexpectedly became unavailable after failing automated health checks. This forced the remaining operational servers to handle additional workloads, putting further pressure on the system.

Engineers later identified problems with a core process responsible for handling secure connections, which became overwhelmed and prevented servers from processing requests.

Why Did Restoration Take More Than 24 Hours?

Microsoft said restoring services was challenging because some servers stopped responding again after being brought back online and exposed to regular traffic.

To resolve the issue, engineers restricted certain types of network traffic, rolled back some servers to earlier configurations, fixed authentication and routing components, and added virtual machines to increase capacity.

The restoration process was further delayed by a backlog of undelivered emails. External mail servers continued retrying messages that could not be delivered during the outage.

To prevent emails from being lost, Microsoft extended its email timeout window to 48 hours.

The company said services were restored gradually, with engineers checking system stability at every stage.

India Among Countries Affected

The outage affected several organisations across the world, including businesses and essential services in India.

In India, IndiGo and Akasa Air faced disruptions to their email support services. Air India rerouted its emails to continue receiving customer messages, while its flight operations remained unaffected.

A major Indian brokerage firm also relied on backup arrangements to manage the Outlook disruption, although communication with clients through Microsoft Teams became difficult.

In the United Kingdom, NHS staff reportedly switched to paper records, pharmacies warned of prescription delays, and a judge in Manchester sent jurors home.

In the United States, a sheriff's office in Colorado asked people to pay bonds in person as online payments depended on Outlook email notifications. Some companies in Japan also returned to fax-based communication.

Even technology companies OpenAI and Anthropic experienced issues with their Microsoft 365 connectors. Meanwhile, electric truck manufacturer Workhorse Group postponed the announcement of its quarterly results to November 16.

Microsoft, which reported more than 450 million paid commercial subscriptions to its Microsoft 365 services in January, said the widespread impact reflected the platform's extensive global reach.