Microsoft 365, Outlook and several other Microsoft services faced a widespread outage on Friday, disrupting access for thousands of users for more than seven hours. The disruption also affected OpenAI and Anthropic services that rely on Microsoft 365 connectors.
Reports of Outlook outages on Downdetector peaked at approximately 1,38,058 around 1.30 am on Friday, before declining to around 34,490 by 4.30 am.
In a statement issued at 3.30 am, Microsoft said it was working to restore affected servers, with services gradually recovering as users reconnected.
The company identified an issue with a process responsible for establishing secure connections on affected servers. The process was becoming overwhelmed, preventing servers from processing requests. Microsoft clarified that the problem was not caused by an overall increase in traffic, but by a reduced number of servers available to handle connections.
To address the disruption, Microsoft began testing a configuration change on a subset of servers before a wider rollout. It also initiated infrastructure restarts and reversed a recent network configuration change that coincided with the outage. Temporary traffic restrictions were introduced in certain locations while the company monitored server stability.
The disruption affected Exchange Online, leaving users unable to access mailboxes through Outlook’s web, desktop and mobile applications. Email delivery was also delayed. Other affected services included Microsoft 365 applications, Copilot, SharePoint Online, Power BI, Microsoft Planner and Microsoft To Do.
Teams continued to support core messaging and online meetings largely normally, although features dependent on Exchange Online, including calendars and meeting scheduling, were affected.
The outage extended to third-party AI services. OpenAI reported issues with Microsoft connectors that could prevent new connections and disrupt tools, while Anthropic identified an upstream provider issue affecting its Microsoft 365 connector.
The disruption also affected businesses. Electric truck maker Workhorse Group postponed its third-quarter results announcement from November 12 to November 16, citing business disruptions caused by the outage.
The incident follows another disruption to Microsoft’s Azure cloud platform in recent weeks, which had affected productivity software and businesses across multiple industries.
Source: India Today
