For most of Thursday, the world’s inboxes just stopped working. Emails wouldn’t send. Meetings wouldn’t open. By Friday morning, the problem was still there — and Microsoft, the company that runs the tools half the working world depends on, was still trying to explain what had gone wrong.
The outage began on Thursday, November 12, 2026. Reports started climbing at about 5:25 p.m. GMT, according to outage tracker Downdetector, and within hours the numbers were enormous: more than 130,000 people reported problems with Outlook by 1:27 p.m. Eastern Time, Reuters reported, and by Thursday evening the BBC put the figure at around 140,000 reports from 74 countries. Outlook took the worst of it. Teams went down too. So did Copilot, Microsoft’s AI assistant, along with other Microsoft 365 services that run on Exchange Online — the company’s cloud-based email and scheduling hub. OneDrive and SharePoint were affected too.
A very bad day at the office
The timing couldn’t have been much worse. It was a working Thursday, and the outage landed right in the middle of the business day in Europe and the morning in the Americas. People who couldn’t reach their email did what people always do when the modern tools fail: they went looking for older ones.
Reuters spoke to businesses that dusted off fax machines, picked up desk phones and leaned on Bluetooth to get work done. In Taipei, fax machines came back into service. In Paris, Euronext — the operator of the European stock exchange — told listed companies on Friday morning to phone in their corporate announcements because its email was down. At least one European bond repurchase was halted because the systems behind it couldn’t be reached, according to AAP.
The disruption reached further than office workers. In Australia, the country’s spy agency and federal police were both caught up in it. The Australian Security Intelligence Organisation and the Australian Federal Police confirmed they had been affected, Reuters reported, and the government triggered an agreement to make sure Australia got priority when services were restored. Home Affairs Minister Tony Burke said Microsoft had told him it did not believe the outage was caused by a cyberattack.
That last point mattered. When something this big breaks, the first question everyone asks is whether someone broke it on purpose. Microsoft said no — repeatedly. The company said it was not aware of any malicious activity, and later ruled out both a cyberattack and any link to artificial intelligence.
What Microsoft said went wrong
Microsoft’s own account of the failure changed as the hours passed, and it’s worth being straight about that. At first, the company blamed server trouble: part of its infrastructure was under “elevated load”, it said, because a large number of servers had “unexpectedly become unavailable”, straining the ones that were left. A computer science professor at the University of Reading told the BBC the part of Microsoft’s servers that sets up secure connections had been swamped, creating a snowball effect as servers stopped answering.
By Friday, the explanation had shifted. Microsoft said it was rolling back a network change, and then issued a fuller statement: the incident “was introduced by an issue during an earlier network capacity upgrade that surfaced following a recent network change”. The company said it had addressed the underlying issue and was restoring service to the remaining customers and regions — but it stopped short of declaring the outage over.
It also apologised, in unusually plain language for a company statement. “We are deeply sorry for the disruption this incident has caused our customers and partners,” Microsoft said. “We know the trust they place in our services and take that responsibility extremely seriously. We are seeing broad recovery and stability across our services.”
By noon GMT on Friday, Reuters reported “encouraging recovery progress” in Europe and improvements in North America, though users could still expect problems while recovery continued. AAP described the outage as one of the longest in Microsoft’s history and the second disruption to its services this year.
How big is “big”?
Here’s the scale of what was at stake. Microsoft says on its website that more than 430 million people use its 365 services, according to Reuters. The Associated Press reported that the company said in January it had more than 450 million paid Microsoft 365 commercial subscriptions. When a system that size stumbles, the stumble is felt everywhere — in banks, in shipping firms, in government offices, in schools.
And yet, for all the chaos, most organisations kept their core systems running. The damage was mostly to the everyday plumbing of office life: the email that confirms a deal, the Teams call that starts a meeting, the calendar that tells you where to be. Annoying, expensive, disruptive — but not, for most people, catastrophic.
That’s also why the outage will linger in boardrooms longer than it lingered on screens. Companies pay Microsoft precisely so they don’t have to think about email servers. A day without email is a reminder of how much of modern work sits on top of a single company’s infrastructure — and how little backup most organisations have when it fails. Reuters’ Breakingviews column made the point bluntly: the outage “will supercharge backup plans”.
What we still don’t know
Microsoft has promised a full post-incident report once its review is complete, but as of Friday it had not published a definitive root cause. The company’s statements describe a network capacity upgrade that went wrong and a network change that brought the problem to the surface — but the precise chain of events, and why it took more than 24 hours to fix, is still unclear.
There are other questions, too. How many people were actually affected? Microsoft hasn’t said. The Downdetector numbers — 130,000 reports here, 140,000 there — only count the people who bothered to report a problem, so the real number is almost certainly much higher.
What happens next
Services are coming back, region by region. If your Outlook was down on Thursday, it was very likely working again by late Friday — or close to it.
The longer story will play out over the next few weeks. Microsoft’s post-incident report will be read closely by its biggest customers, and by its competitors, who will be quick to point out that their systems stayed up. Regulators may ask questions too, especially in Europe, where the outage hit government agencies and financial markets.
And for everyone else, there’s a smaller lesson, the kind you only learn the hard way. Back up the things that matter. Keep a phone number for the people you usually email. And maybe — just maybe — don’t throw the fax machine away yet.
Sources: Reuters; BBC; Associated Press; AAP; Al Jazeera.
