Microsoft suffered a widespread outage on Thursday and Friday that disrupted millions of customers. Connectivity problems began shortly before 1 p.m. ET Thursday and continued into Friday. Outlook and Teams were affected, along with Microsoft 365 services including SharePoint and Copilot. External services that connect to Outlook Calendar were also hit.

Microsoft said it was not aware of any malicious activity causing the outage. It initially blamed a traffic surge in part of its infrastructure and issues with a component that processes server health. Its early updates said a number of servers were unexpectedly unavailable, which strained the remaining infrastructure. Some servers were failing automated health checks.

In an update around 5 a.m. ET Friday, Microsoft said users may still be unable to connect to multiple Microsoft 365 products, including Outlook on web or desktop. The company did not give a timeline for full restoration. It said Teams access was mostly available. Microsoft reported "incremental improvement in several workloads," but said service was variable and full capacity had not been restored. It also said it is extending the retry window for delayed emails by up to 48 hours to help protect messages.

Microsoft shares were 2.6% lower in premarket trade, according to the report. Richemont delayed its earnings release on Friday because of the outage. Workhorse Group moved its third-quarter results from Nov. 12 to Nov. 16, citing business disruptions tied to the Microsoft outage. Air India said it temporarily rerouted emails to keep receiving customer messages, and said its flight operations were not affected. The U.K.'s National Health Service said some of its services were affected but that patients should attend appointments as normal.

Australian Home Affairs and Cyber Security Minister Tony Burke said Microsoft "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," according to Reuters. The report notes that a faulty CrowdStrike update caused one of the world's biggest IT outages in 2024.

Amazon Web Services and Google users also reported outages on Thursday. Amazon said its services were "operating normally" and that an "unrelated disruption elsewhere on the internet is prompting some inaccurate news reports."