Microsoft Restores Teams and Outlook After 24-Hour Global Outage

Microsoft restored service to Teams, Outlook and its remaining products on Saturday, ending a global outage that had disrupted business and government communications for more than 24 hours. The company attributed the failure to server issues tied to Exchange Online, its cloud-based email and scheduling hub, and said it had found no evidence of malicious activity.

"We have completed our efforts to address the underlying issue of the incident and restored service to the remaining impacted customers and regions," Microsoft posted on X.

How big was the disruption?

The scale was measurable in raw numbers. Downdetector, the outage-tracking platform owned by Ookla, logged more than 7.4 million reports worldwide during the incident, with reports peaking at nearly 20,000 per minute. That peak ran more than 1,500 times normal levels, according to Ookla. Reports began climbing around 1725 GMT on Thursday.

The outage ranks among the longest in Microsoft's history. It is also the second disruption to Microsoft's services this year, following a Microsoft 365 outage in January and another in October last year. Last month, a separate outage of the Azure cloud platform hit Microsoft's productivity software suite and a range of industries worldwide.

Outlook and Teams serve hundreds of millions of users and rank among the most widely used workplace applications in the world. For the duration of the outage, users could not send emails, manage calendars or host virtual meetings — the basic functions of the modern office. Applications not connected to Exchange Online remained operational, and organizations that host Microsoft services on their own servers, rather than in the cloud, were somewhat spared.

The incident also affected Microsoft's Copilot AI assistant. The company ruled out AI as the cause.

"It shows how much of the working day now runs through one provider's email and collaboration tools," said Luke Kehoe, lead industry analyst at Ookla.

What does the outage cost?

The financial toll, while significant, appears contained relative to recent precedent. Mario De Cicco, vice president of European financial institutions at rating agency Morningstar DBRS, estimated global insured losses from the incident at between $300 million and $500 million. That figure sits well below the estimated $400 million to $1.5 billion toll of the 2024 CrowdStrike outage, which crashed more than 8 million Windows-based computers and caused widespread disruption.

Disruptions and losses could still generate numerous insurance claims, De Cicco said, though he expects the overall hit to insurers to be limited.

Microsoft's stock showed little reaction. Shares closed flat at $523.88 on Friday and have gained roughly 8 percent so far this year.

Who was affected?

The outage's reach spanned governments, financial markets and airlines across multiple continents:

• Government agencies in Australia, Japan and the United States experienced disruptions.
• The UK's Metropolitan Police said the loss of email and other services affected its ability to report some crimes online, though its ability to respond to calls was not affected.
• The NHS said local services turned to alternate measures, including other IT systems and paper records.
• European exchange operator Euronext reported email disruptions.
• British insurer Aviva activated backups for its earnings calls.
• Danish shipping giant Maersk warned customers of delayed updates.
• Indian airlines IndiGo, Akasa Air and Air India said their email support services were impacted.
• OpenAI and Anthropic faced issues with Microsoft connectors, later resolved.

A spokesperson for the UK government said it was working with Microsoft to find a solution for organizations such as the NHS and the Metropolitan Police.

In Australia, where the spy agency and federal police were among the organizations caught in the outage, Cyber Security Minister Tony Burke said Microsoft does not suspect a cyberattack. "The impact that they are dealing with ... is very much on email systems," the minister said.

The financial sector felt the failure most acutely. The outage disrupted fund management at Taiwanese securities firms, life insurers and investment trust companies. One of the companies cancelled a bond repurchase transaction, a source familiar with the situation told Reuters. A second Taiwanese financial company resorted to fax machines to confirm trades.

Corporate reporting schedules also slipped. American electric truck maker Workhorse Group rescheduled its Thursday results to November 16. Switzerland's Richemont briefly delayed its first-half results announcement on Friday.

Why does concentration in one vendor matter?

The incident deepens a structural question about the global economy's reliance on a handful of Big Tech companies that supply both the essential software and the cloud infrastructure underpinning it. Outage reports spiked as employees began their workdays across Asia and Europe, according to Ookla — a pattern that mapped the global workday onto a single provider's status page.

"The bigger worry is that this is not the first Microsoft 365 outage this year," said Josh Gilbert, a market analyst at trading platform eToro. "If reliability starts to look like a recurring problem, it hands every IT department a reason to think twice before putting even more of their business in one provider's hands."

Some analysts question whether even repeated incidents can push customers toward rivals. The switching costs of replacing tools embedded so deeply in daily operations remain steep, which limits the competitive consequences of any single outage.

For now, Microsoft has restored service and pointed to server issues rather than an attack. The deeper test will be whether the second major disruption of 2025 alters procurement decisions, or whether the economics of switching keep hundreds of millions of users exactly where they were when the reports started climbing on Thursday.