Outlook outage: Microsoft reports 'issues' with Teams and email

Microsoft is struggling to restore Outlook, Teams, Copilot and other Microsoft 365 services after a widespread outage that began on Thursday around 18:00 UTC and stretched past 12 hours into Friday, according to The Register. The outage has affected users around the world, including hospitals, GPs, schools and police across the UK, as reported by The Guardian, and has forced airlines to divert customers to alternative communication methods, according to NPR. NPR also reported that jails in the United States were unable to release people on bail because their email systems were down.

Microsoft said the problems affect Microsoft 365 services "that interact with Exchange Online and email services," while services that do not need Exchange Online remain functional, The Register reported. Yahoo Finance UK said Microsoft attributed the outage to "elevated load," explaining that its servers had become "unexpectedly unavailable," rather than an increase in traffic. The company has not said exactly why the servers became unavailable.

Microsoft initially blamed a "problem that's causing servers to fail automated health checks and become unavailable," The Register reported, and later admitted that "Actions taken thus far have not provided the anticipated relief." The company's status page updates described applying infrastructure capacity improvements, reviewing traffic flows, scaling up virtual machines, and encountering issues with machines stuck in a bad state.

Microsoft said it has found "no indication this is the result of malicious activity," and executive vice president Charles Lamanna said Microsoft had ruled out a cyber attack, according to Yahoo Finance UK. NPR reported that Microsoft posted on its website that "we have no evidence of malicious activity." Experts cited by Yahoo Finance UK said the outage was most likely caused by a software update containing a bug, though the exact details remain unclear.

More than 430 million people use Microsoft 365 services, according to Microsoft's website as cited by Yahoo Finance UK and NPR. NPR reported that as of around 7 a.m. Eastern time, services in Europe and North America were starting to come back online, with some stability returning. Microsoft's latest status update, as reported by The Register, said the company is "continuing to pursue multiple workstreams to pinpoint the underlying cause of the traffic influx and advance the recoverability of the backend servers," and that it is taking a measured approach to identify and repair affected infrastructure.