Microsoft restores some servers after global 365 outage

A widespread Microsoft ↗ 0.36% 365 outage on Thursday, November 12, cut off business and consumer users from Outlook email, Teams, Copilot and other cloud services in several regions. Reports on outage tracker Downdetector peaked at nearly 130,000 for Outlook just after 1 p.m. ET, AP reported. By late afternoon, Microsoft said some servers were coming back online. It had not given a root cause or said when service would be fully restored.apnews.com

Servers fell offline

Microsoft first reported problems with Exchange Online mailboxes in the Americas. It later said "the issue may affect Microsoft 365 service connectivity for users in any region," according to The Post and Courier. In a Microsoft 365 admin center advisory tracked as MO1550821, the company listed Teams, SharePoint Online, Microsoft 365 Copilot and Defender XDR among the affected services, BleepingComputer reported.bleepingcomputer.com+1

Microsoft first blamed elevated load on its infrastructure. It later said "the elevated load isn't driven by an increase in traffic, but by a number of servers being unexpectedly unavailable; straining the remaining infrastructure," BleepingComputer reported. The servers were failing automated health checks, and Microsoft was also looking into high processor usage on the affected machines, according to SecurityWeek. "We've not identified any recent change correlated with the start of impact," the company said, CNET reported. Microsoft has disclosed no evidence of a cyberattack, SecurityWeek noted.securityweek.com+2

Partial recovery

"We've paused all deployments, we're moving additional traffic off the affected infrastructure, and we're restarting affected servers to return them to service," Microsoft said in a social media post, The Arizona Republic reported. In a 4 p.m. ET update, the company said it had "validated an alternative service health check method, which allowed a subset of affected servers to successfully return to service." It added that it was applying the change more broadly and preparing automated systems to detect and restart unresponsive servers, according to The Wichita Eagle. About 49,000 Outlook problem reports were still showing on Downdetector at 4:50 p.m. ET, the same report said.azcentral.com+1

Fresh scrutiny of cloud reliance

Users said they could not send or receive email, and some inboxes stayed "effectively frozen in time," The Seattle Times reported. At times, Microsoft's admin center and its own status page would not load, according to TechCrunch and Insurance Business. That publication said the disruption has put cloud concentration risk back on insurance brokers' radar.techcrunch.com+2

TechCrunch noted that a days-long Microsoft 365 outage in September was blamed on a "core authentication configuration" issue. A Microsoft spokesperson said Thursday, "We appreciate our customers' patience while we work to restore services as soon as possible".seattletimes.com+1