Microsoft services, including Outlook and Teams, suffered a prolonged outage on Thursday, disrupting businesses and government agencies worldwide for about 10 hours as the technology company struggled to restore affected servers.
The disruption affected users of the company’s Microsoft 365 productivity suite, with Microsoft saying efforts to improve service availability were progressing slower than expected.
In its latest update, the company said it was exploring alternative measures to address persistent traffic management imbalances.
“We’re identifying alternate workstreams that can be applied to increase capacity in the face of sustained traffic management imbalances,” it said.
Outage monitoring platform Downdetector recorded more than 130,000 reports of Outlook problems in the United States at the peak of the disruption around 1 p.m. Eastern Time on Thursday.
Although the number of complaints later declined, more than 25,000 reports were still recorded at 9:30 p.m.
Eastern Time, while disruptions were also reported across the Asia-Pacific region, including India, Australia and Japan, in the early hours of Friday.
Microsoft said the disruption primarily affected features of Microsoft 365 that depended on Exchange Online, its cloud-based messaging platform responsible for email, calendars, contacts and tasks.
Services and features that did not rely on Exchange Online remained operational, according to the company.
CYBERATTACK RULED OUT
Australia’s Home Affairs and Cyber Security Minister, Tony Burke, said Microsoft did not believe the disruption was caused by 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.
“The impact that they are dealing with … is very much on email systems,” the minister added.
Australia’s spy agency and federal police were among organisations affected by the outage on Friday.
The disruption has drawn comparisons with the 2024 CrowdStrike malfunction, which caused widespread technology failures across hospitals, banks, airports and other critical services globally.
The United States House of Representatives also confirmed that its users were affected, adding that its engineers were working with Microsoft to address the problem.
Microsoft had earlier attributed the disruption to the unexpected unavailability of several servers, dismissing increased traffic as the cause.
The company said it was redirecting traffic through alternative routes and working to restore the affected servers.
It also reported that the servers already recovered had remained stable.
“As capacity is restored, users may experience a gradual recovery as their clients reconnect,” Microsoft said in an earlier statement.
At 6 p.m.
Eastern Time on Thursday, the company reported limited recovery as users gradually reconnected to its services.
BUSINESSES COUNT LOSSES
The outage also affected other technology companies relying on Microsoft’s infrastructure.
OpenAI said it was investigating problems with its Microsoft connectors, warning that new connections could fail and some tools might not function as expected.
Anthropic also reported an issue with an upstream provider affecting its Microsoft 365 connector.
The disruption had business consequences for electric truck manufacturer Workhorse Group, which postponed the release of its third-quarter financial results from November 12 to November 16, citing the global Microsoft outage.
The incident follows another disruption involving Microsoft’s Azure cloud platform last month, which affected its productivity software and businesses across several industries worldwide.
