Is Outlook still down? Microsoft’s patch helps, not everywhere yet

The short answer is that recovery has started but is not finished. In its most recent update before this article went live, Microsoft said it had applied a patch to an upstream component that handles authentication and routing configuration on a portion of its infrastructure, and that it was seeing positive results for server stability there. It said it was working to expand that patch to servers in other active regions as they come back online.

Earlier on Friday the company described only marginal success from its repair work, and overnight it admitted that its first fixes were not taking as expected. Rerouting traffic and selectively blocking some of it produced partial recovery, but not a lasting one.

Microsoft has not given a time for full restoration. It has warned that recovery will be gradual, because each app has to reconnect on its own once the servers behind it are healthy. So a coworker’s inbox may come back an hour before yours does.

This is not just Outlook. Microsoft’s own incident notice for business customers, tracked as MO1550821, lists trouble connecting to these services:

• Exchange Online, the system behind work and school Outlook mailboxes
• Microsoft Teams chat and meetings
• SharePoint Online, where many companies keep shared files
• Microsoft 365 Copilot, the AI assistant built into Office apps
• Microsoft Defender XDR, a security tool used by IT teams

Home users are hit too. Microsoft says the problem reaches Outlook.com, OneDrive, OneNote, Microsoft To Do, Teams and the web versions of Microsoft 365, and possibly other services. Experiences vary a lot: some people can still use Teams messaging and meetings normally, while others cannot send or receive email, open certain files or see their calendar details.

Microsoft first blamed unusually heavy load across several regions. It then clarified that the load was not caused by more people using its services. Instead, a number of servers unexpectedly became unavailable, and the traffic they normally carry piled onto the remaining machines, straining them as well. The company later said a core process on the affected servers was becoming overwhelmed, which cut capacity further.

To stop the slide, Microsoft says it paused all deployments, spread connection traffic across its worldwide infrastructure, moved more traffic away from the worst-hit systems and restarted affected servers. It also looked at whether rolling back a small number of recent configuration updates could speed things up.

Is it a hack? Microsoft says no. Charles Lamanna, the executive vice president who runs Copilot and agents at Microsoft, said on X that there is no indication the outage stems from malicious or cyber activity, and the company’s status page repeats that it is not aware of any. Australia’s home affairs minister, Tony Burke, said Microsoft believes the situation resembles the 2024 CrowdStrike incident, which he described as an update gone awry. Microsoft has promised a post-incident report with the full root cause once the problem is fixed.

Big. Microsoft says more than 430 million people use its Microsoft 365 apps. On Thursday evening, Downdetector logged problem reports about Outlook from 140,000 people in 74 countries, and the true number is almost certainly higher because most people never file a report.

The incident started at 1:26 PM Eastern on Thursday, which is around 6pm in the UK, according to Microsoft’s own timeline for business customers. As workdays began in Asia and then Europe, the reports followed the sun:

• Japan’s government said its email went offline and switched to text messages and other formats as an emergency measure, and its trade minister called the impact major.
• Australia’s spy agency and federal police were among the organizations disrupted, Australian schools and courts opened to dead inboxes, and Singapore’s government was hit too.
• OpenAI and Anthropic both reported problems with tools that connect to Microsoft services.
• Bankers at Morgan Stanley and Goldman Sachs in Hong Kong were reportedly locked out of email and Teams, and two Indian airlines, IndiGo and Akasa, lost their email support channels.
• US cities including Miami Beach and Austin told residents to phone rather than email.

For most people the outage is an inconvenience, but it changes how you should reach anyone who runs on Microsoft email today. In the UK, several police forces, including Hertfordshire and Dorset, said they cannot reliably receive online crime reports. They ask people to call 101 for time-critical reports that are not emergencies, and 999 in an emergency. If your report can wait, Dorset Police suggests submitting the online form after Microsoft restores service.

NHS services are affected as well. One London mental health trust asked patients to call their usual service instead of emailing, warning that emails may not be received. Another trust in Greater Manchester said its care systems were not affected and patients should attend appointments as planned. Schools in London and Salisbury asked parents to phone in absences rather than email.

The UK government says it is working closely with Microsoft and has contingency plans in place. Microsoft has not given country-by-country figures for the US or Canada, but reports first surged in the Americas before the problem spread worldwide.

1. Check Microsoft’s status, not social media rumors. The Microsoft 365 status page and the company’s status account on X carry the official updates, including the current repair stage.
2. Phone for anything urgent. If you emailed a school, clinic, council or employer since Thursday afternoon, assume it may not have arrived and confirm by phone.
3. Expect a staggered return. Because apps reconnect one by one, your Outlook may recover before your Teams, or after a colleague’s. Give it time before assuming your own account is the problem.
4. Watch out for fake tech support. Banks including Standard Chartered and ING Australia, and the Victorian government in Australia, have warned that scammers are posing as support staff to exploit the chaos. Hang up on unexpected support calls about the outage and never hand over passwords or codes.
5. Keep a record of anything time-sensitive. If a deadline, payment or report was missed because email failed, note the time. Dorset Police, for one, is already telling people to resubmit non-urgent forms once service returns.