Key facts
- Microsoft said server adjustments did not produce sustained recovery, though some regions showed partial improvement.
- Downdetector showed more than 18,000 US Outlook problem reports at 11:30 p.m. ET on November 12.
- Microsoft said it was not aware of any malicious activity causing the outage.
- Australian minister Tony Burke said Microsoft believed the cause resembled the 2024 CrowdStrike update malfunction.
- The US House of Representatives said the outage affected its users and its engineers were working with Microsoft.
- A source said one Taiwanese investment trust company canceled a scheduled bond repurchase agreement.
A disruption of Microsoft services including Outlook, Teams and Copilot stretched into Asia-Pacific business hours on November 13, 2026, after affecting thousands of US users. Microsoft blamed server problems for the outage and said it was working to resolve them.
In its latest update, Microsoft said it had applied adjustments to the affected servers, but they did not result in sustained recovery. It said it had observed some partial recovery in the regions where it applied the adjustments. "We're reviewing what additional actions we can take to improve overall infrastructure stability," the company said on X.
Downdetector, which tracks outages by collating status reports from a number of sources, showed more than 18,000 reports of Outlook problems in the US at 11:30 p.m. ET on November 12. At its peak, it showed more than 130,000 US Outlook reports around 1 p.m. ET on November 12. The outage had lasted about 12 hours as of the report.
In a service health notice, Microsoft said features of Microsoft 365 services that depended on Exchange Online and email were affected, while elements that did not rely on Exchange Online remained functional. The company said it was "not aware" of any malicious activity causing the outage.
Australian Home Affairs and Cyber Security Minister Tony Burke said Microsoft believed it was not dealing with a cyberattack. "They believe they are dealing in some ways similar to what we saw with respect to CrowdStrike where there is an update that has gone awry," Burke said at a press conference. Australia's spy agency and federal police were among organizations caught up in the outage on November 13.
The US House of Representatives said the outage impacted its users and its engineers were working with Microsoft. Japanese Deputy Chief Cabinet Secretary Masanao Ozaki told reporters the outage was affecting the government's information system infrastructure. OpenAI and Anthropic said they had faced issues with Microsoft connectors, while Indian airlines IndiGo and Akasa Air said their email support services were impacted.
The outage also disrupted fund management at Taiwanese securities firms, life insurers and investment trust companies. One company canceled a bond repurchase agreement transaction it had already scheduled, a source familiar with the situation told Reuters, declining to name the company.
Josh Gilbert, a market analyst at trading platform eToro, said investors would likely look past the outage but that repeated disruptions could hurt Microsoft over time. "The bigger worry is that this isn't the first 365 outage this year, and 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," Gilbert said.
Microsoft faced an outage with its 365 services in January 2026 and in October 2025. Microsoft reported an Azure cloud platform outage in October 2026 that impacted its productivity software and a range of industries worldwide. Workhorse Group, which was expected to report third-quarter results on November 12, rescheduled the release to November 16, citing business disruptions caused by the outage.