New Delhi: A global Microsoft outage disrupted Outlook, Microsoft 365 and several other services for more than 11 hours on Friday, leaving users unable to access emails, files and workplace applications. The disruption also affected third-party platforms, including OpenAI and Anthropic’s Microsoft 365 connectors, as the company worked to restore its systems.
Microsoft said services were gradually recovering as it restored affected servers and shifted traffic to alternate routes. The company has not confirmed the precise cause of the outage but has identified an overwhelmed secure-connection process on affected servers as a key factor.
Which services were affected?
The disruption primarily affected Exchange Online, Microsoft’s cloud-based email service. Users reported problems accessing Outlook through web, desktop and mobile applications, while email delivery was also delayed.
The outage spread to several other Microsoft applications, including Microsoft 365, Copilot, Planner, Microsoft To Do, Defender, Purview, SharePoint Online, Power BI and Windows 365. Some Microsoft 365 Education features and Microsoft Intune services were also affected.
Microsoft Copilot users reported difficulties loading Copilot Chat and accessing work-related information, including emails, calendars and files. Users also experienced problems accessing recently used files and certain pages of the Microsoft 365 admin centre.
Microsoft Teams continued to support core messaging and online meetings largely normally. However, features dependent on Exchange Online, including calendars and meeting scheduling, were disrupted.
Businesses and government services report impact
The outage affected businesses and government organizations in Australia, prompting the country’s national cyber security coordinator, Lieutenant General Michelle McGuinness, to look into the disruption.
A spokesperson for Australia’s home affairs minister confirmed that McGuinness was aware of the outage and was examining the issue, ABC reported. The disruption began affecting Australian users shortly after 3 am AEDT.
The impact extended to third-party technology platforms. OpenAI said it was investigating an issue with Microsoft connectors that could prevent new connections and cause tools to malfunction. Anthropic also identified an issue with an upstream provider affecting its Microsoft 365 connector.
The US electric truck maker Workhorse Group postponed its third-quarter results announcement from November 12 to November 16, citing business disruptions caused by the global outage.
In India, IndiGo issued a service advisory on X, warning that its email support services were affected by the Microsoft disruption. The airline said customers might not be able to reach it through email and directed those requiring urgent assistance to its 6E Skai chatbot through its website or mobile application.
What caused the outage?
Microsoft’s investigation identified a process responsible for establishing secure connections on affected servers as a key factor behind the disruption. According to the company, the process became overwhelmed, causing servers to stop processing requests.
The company also said it was investigating recent configuration changes that may have contributed to the problem. It began reversing a network configuration change that coincided with the start of the outage to determine whether it had played a role.
In an update posted on X, Microsoft initially said it was investigating problems affecting Exchange Online mailboxes through multiple connection methods in the Americas. It later confirmed that the disruption could affect Microsoft 365 connectivity in any region.
Microsoft also introduced configuration changes and restarted affected infrastructure while restricting traffic in certain locations. It said the measures were intended to stabilise servers before gradually restoring additional traffic.
In its latest updates, the company said it was scaling up virtual machines to increase capacity and reduce pressure on its systems. It was also attempting to fix machines stuck in a faulty state by forcing them to synchronize recent network changes, although some machines were not syncing as expected.
Microsoft clarified that the outage was not caused by an overall increase in traffic but by fewer servers being available to handle requests. A Microsoft spokesperson told ABC News that there was “no indication” the disruption had been caused by a cyberattack.
The company said it was continuing to monitor the recovery process and would make further adjustments if required.