WASHINGTON, United States- Microsoft has apologised after a major global outage disrupted Outlook, Teams, Copilot and other Microsoft 365 services, saying the incident stemmed from a technical problem linked to an earlier network capacity upgrade.
The company said the outage was not caused by a cyberattack, artificial intelligence or AI agents, amid widespread disruption to email, workplace communications and cloud-based tools used by businesses, governments and institutions worldwide.
“We are deeply sorry for the disruption this incident has caused our customers and partners,” Microsoft said in a statement, adding that it was seeing “broad recovery and stability” across its services.
Microsoft said the underlying issue emerged after a recent network change exposed a fault introduced during a previous capacity upgrade.
“The incident was introduced by an issue during an earlier network capacity upgrade that surfaced following a recent network change,” the technology giant said.
“We have addressed the underlying issue and continue to restore service to remaining customers and regions.”
The outage, first reported on Thursday, affected a broad range of Microsoft 365 products, including Outlook email, Teams collaboration software and Copilot, Microsoft’s AI assistant.
Users in multiple countries reported difficulties signing in, sending and receiving emails, accessing workplace platforms and using online services reliant on Microsoft infrastructure.
Microsoft said it chose a gradual recovery process because of the scale of demand on its systems, with engineers validating stability before restoring more users and regions.
“Given the scale of demand, we restored services gradually, validating stability at each stage,” the company said. “While this took longer, it helped ensure a stable restoration.”
The controlled approach meant some customers continued to experience intermittent access problems and delayed email delivery even as service health improved. Microsoft said email queues were being reduced as infrastructure capacity stabilised. AP News
The disruption had effects beyond office inboxes, affecting businesses, schools, government agencies and some public services in several countries. Reports indicated that organisations dependent on Microsoft email and cloud tools turned to alternative communication channels as they waited for systems to return.
Microsoft has more than 450 million paid Microsoft 365 commercial subscriptions, illustrating the scale of potential disruption when its shared infrastructure experiences a failure.
The company has not linked the incident to malicious activity or recent workforce changes.
Instead, it said its focus remains on completing restoration for affected customers and reviewing how the network issue developed.
Microsoft said it will publish a full post-incident report once its internal review is complete, including further details on the root cause and measures intended to prevent a repeat of the outage.
