Microsoft 365 and Outlook outage affects thousands of US users

Microsoft says it is working to tackle "connectivity problems" after users worldwide reported outages on Thursday.

Services including Teams, Outlook and Microsoft's AI software Copilot were affected.

The tech giant said a part of its infrastructure was experiencing "elevated load", which was likely contributing to connectivity errors.

While the issue was originally reported in the US, Microsoft said the connectivity problems could affect users "in any region".

At around 18:30 GMT on Thursday evening, monitoring website Downdetector showed a spike in UK users reporting issues with Microsoft products.

Similarly for the US, the monitoring site suggested there had been over 131,000 reports of Microsoft Outlook problems at 18:15 GMT.

"We determined the elevated load isn't driven by an increase in traffic, but by a number of servers being unexpectedly unavailable; straining the remaining infrastructure," Microsoft said in a statement.

In a further update issued at 19:50 GMT, Microsoft said it was "testing a configuration" to fix the problem, which was "causing servers to fail automated health checks and become unavailable".

All affected servers had been restarted, it added.

NBC News reporting

As of around 1:30 p.m. ET, more than 120,000 users on outage tracker Downdetector reported problems accessing Outlook — with many saying they couldn’t send and receive emails, or encountering delays.

Thousands also reported issues with Microsoft’s workplace messaging app Teams, as well as its AI assistant Copilot and wider Microsoft 365 services.

Microsoft said that it was investigating.

In updates posted on social media, Redmond, Washington-based Microsoft said it was aware of users “experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas.”

Microsoft later added that a portion of its infrastructure was “experiencing elevated load” — which it said was “likely contributing to the connectivity errors.” The company said it would begin ”redistributing” traffic to help balance the load.

Microsoft did not immediately provide further information. Earlier in the day, the company said it had “successfully restored” problems related to Microsoft Teams in North America, although some users continued to report connectivity issues.

Why it matters

The outage disrupted email, workplace messaging and AI assistant services for Microsoft 365 users across the US and other regions, with Downdetector recording more than 131,000 Outlook reports in the US and more than 120,000 Outlook reports as of around 1:30 p.m. ET.

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Sources

• bbc.com: Microsoft outage sees Teams, Outlook and Copilot suffer 'connectivity issues'
• nbcnews.com: Is Outlook down? Widespread outage hits Microsoft apps

This article was drafted with AI assistance and checked against the sources above. Company claims are reported as claims. Cover image is AI-generated.