Microsoft outage eases after nearly 24 hours, 7.4 million reports logged

Summary:

The latest:

A global failure of Microsoft Outlook and Teams eased on Friday after roughly 24 hours that froze corporate email, calendars and virtual meetings across four continents. Microsoft said server issues caused the incident, which also hit its Copilot assistant, and that a broader roll-out of fixes was stabilizing systems. The company said it was not aware of any malicious activity and ruled out AI as the cause.

Details:

• The scale: Downdetector logged more than 7.4 million reports worldwide, peaking at nearly 20,000 a minute, over 1,500 times normal levels, according to parent company Ookla. Reports began climbing around 1725 GMT on Thursday and spiked again as workdays opened across Asia and Europe.
• The technical cause: Microsoft said the disruption specifically hit features tied to Exchange Online, its cloud-based email and scheduling hub, leaving unconnected applications operational. Organizations hosting Microsoft services on their own servers rather than in the cloud were somewhat spared the worst of the failure.
• Governments hit: Agencies from Australia and Japan to the United States were affected. A British government spokesperson said officials were working with Microsoft on a fix for an outage that struck the NHS and London’s Metropolitan Police, which said online crime reporting was degraded though emergency call response was not.
• Back to paper and fax: The NHS said local services switched to alternate IT systems and paper records. A Taiwanese financial company used fax to confirm trades, a source told Reuters, while another cancelled a bond repurchase transaction, according to a second source. Fund management at Taiwanese securities firms, life insurers and investment trusts was disrupted.
• Corporate fallout: Euronext reported email disruptions, Aviva activated backups for its earnings calls and Maersk warned customers of delayed updates. OpenAI and Anthropic faced issues with Microsoft connectors. IndiGo, Akasa Air and Air India said email support services were hit, and trading firms reported delays.
• Earnings delayed: US electric truck maker Workhorse Group pushed its results from Thursday to November 16, and Switzerland’s Richemont briefly delayed its first-half results announcement on Friday.
• Insured losses: Mario De Cicco, vice president of European financial institutions at Morningstar DBRS, estimated global insured losses at $300 million to $500 million. That sits below the $400 million to $1.5 billion toll from the 2024 CrowdStrike outage, which crashed more than 8 million Windows computers.
• Canberra’s read: Australian Cyber Security Minister Tony Burke said Microsoft does not suspect a cyberattack, and that the impact was “very much on email systems.” Australia’s spy agency and federal police were among the organizations caught in the disruption.
• The pattern: Microsoft faced a 365 outage in January and another in October last year. Last month it reported an Azure cloud failure that hit its productivity suite and industries worldwide. Josh Gilbert, market analyst at eToro, said a recurring reliability problem would give IT departments reason to hesitate before deepening their exposure.
• Market reaction: Microsoft shares were slightly higher in afternoon trading, with the stock up roughly 8% so far this year. Some analysts questioned whether such incidents can shift customers to rivals, given the steep cost of replacing tools embedded so deeply in daily operations.

Background:

Outlook and Teams count hundreds of millions of users and sit at the center of workplace communication, handling email, calendars and virtual meetings. Both run on Exchange Online, the cloud service Microsoft identified as the point of failure in this incident.

Between the lines:

The outage deepens questions about global reliance on a handful of Big Tech firms supplying both essential software and the cloud infrastructure beneath it. Ookla analyst Luke Kehoe said the episode shows how much of the working day now runs through one provider’s email and collaboration tools. The counterweight, as analysts noted, is switching costs: the same depth of integration that made the failure so disruptive also makes leaving expensive.

What’s next

Watch whether Microsoft publishes a post-incident report naming the server fault, Workhorse Group’s rescheduled results on November 16, and whether insurers begin logging claims against De Cicco’s $300-500 million estimate.