Microsoft is continuing to battle a major outage affecting several of its services, including Outlook, after acknowledging that restoration efforts were “not taking as expected.”
Roughly 130,000 users in the United States reported problems with Outlook shortly after 1 p.m. Eastern time on Thursday, according to Downdetector.
Although the number of fresh reports has declined, tens of thousands of users around the world—or potentially more—were still unable to access their inboxes or send messages.
Microsoft’s subscription software suite is used by more than 430 million people, although the company has not disclosed how many customers were directly affected by the disruption.
Users also reported trouble with Microsoft Teams, the Copilot AI assistant and several other Microsoft 365 products.
On Thursday night, Microsoft said it was exploring “alternate workstreams” to increase capacity and address “sustained traffic management imbalances” behind the continuing disruption.
Earlier in the day, the company said infrastructure facing an “elevated load across multiple regions” was probably contributing to the connectivity failures.
Charles Lamanna, a Microsoft executive vice president, wrote Thursday night on X: “For now I can confirm that there is no indication this is the result of malicious or cyber activity.”
Microsoft said Thursday night that its efforts to restore services after the widespread outage were “not taking as expected”
Thousands of users worldwide were unable to access Outlook and other Microsoft services for much of the day
Microsoft previously said several servers had become “unexpectedly unavailable” after failing during automated health checks.
The company did not immediately explain what had caused the failures.
Microsoft later said it was testing a repair and deploying an alternative process to return the affected servers to service.
“We’re aggressively pursuing all pathways to reduce impact,” the company’s 365 Status account wrote on X.
Around noon, Microsoft posted that “mitigative actions” had “successfully restored service health and functionality” across North America.
However, users continued to report problems, saying the outage remained active during the middle of the working day for many customers.
Australian Home Affairs Minister Tony Burke also said Microsoft had told him it did not believe a cyberattack was responsible, according to Reuters.
Microsoft said earlier Thursday that infrastructure under “elevated load across multiple regions” was likely contributing to the extensive outage
OpenAI said the Microsoft disruption caused ChatGPT to experience “degraded performance” on Thursday
The Microsoft disruption also spilled over to other technology platforms.
OpenAI said Thursday afternoon that it was investigating a problem with Microsoft connectors, warning that new connections could fail and tools might not operate properly.
OpenAI also reported that ChatGPT was operating with “degraded performance.”
Anthropic, another major AI company, said its users were encountering problems linked to the Microsoft 365 service incident.
According to Anthropic, mail, calendar and search features within its Microsoft 365 connector were failing for most requests.
The outage also disrupted jail operations in parts of the United States. The Arapahoe Sheriff’s Office in Colorado said Thursday evening on X that it could not receive the email alerts required to process online bond payments.
People seeking immediate release on bond were therefore instructed to complete the process in person at the jail.
The New York City Department of Investigation said the outage had also led to the suspension of evictions scheduled for Friday.
Microsoft has said that more than 90 percent of Fortune 500 companies use Copilot, its artificial intelligence assistant.
More than 430 million people use Microsoft’s subscription services (pictured: the company’s campus in Redmond, Washington)
The outage occurred in the same week Microsoft issued a security update for an unrelated vulnerability that could allow hackers to steal sign-in details.
Attackers could use that information to impersonate victims and potentially gain access to personal accounts or workplace systems.
Microsoft released a fix on November 10 as part of its regular security updates, but computers remain exposed until the patch is installed.
To install the update, users should open an Office program such as Word, select File, then Account, and choose Update Options followed by Update Now.
In classic Outlook, the account section may instead be labeled Office Account.
The vulnerability has already been exploited in real-world attacks.
Until the update is applied, users should avoid opening unexpected attachments or message files, even when they appear to have been sent by someone they know.