The disruption, which began on Thursday, has affected several Microsoft 365 applications like Microsoft Teams, Copilot and other workplace services. Microsoft's Outlook email service is facing a major global outage on Friday leaving users unable to access their inboxes, send or receive emails, and use several other Microsoft 365 applications. The disruption, which began on Thursday, has also affected Microsoft Teams, Copilot and other workplace services, disrupting businesses, government offices and educational institutions across multiple countries. Microsoft has said it is not aware of any malicious activity causing the outage. (AFP/ Representational)The outage appears to stem from a major infrastructure failure involving Microsoft's servers. The company has acknowledged problems with server stability and elevated workloads, but has yet to provide a complete technical explanation of what triggered the disruption. Track Microsoft outage live updates hereDeep DiveImportantly, Microsoft has said it is not aware of any malicious activity causing the outage, indicating that there is currently no confirmed evidence of a cyberattack. Outlook outage: How many users are affected?The disruption has affected users in several countries, with outage-tracking platform Downdetector recording reports from more than 70 countries. Outlook outage reports in the US peaked at around 138,000 before declining, although users continued to report problems accessing the service. The disruption also affected businesses, government agencies, universities and other institutions dependent on Microsoft's cloud-based services. Why is Outlook down today?The outage is linked to a server-side infrastructure problem involving Microsoft's Exchange Online platform, which powers Outlook's email services. Microsoft's investigation found that a core process on affected servers was becoming overwhelmed. This caused the servers to stop responding to requests and eventually become unavailable. The problem appears to have triggered a cascading infrastructure failure. As some servers became unavailable after failing automated health checks, the workload shifted to the remaining operational servers. This increased the pressure on the available infrastructure, contributing to further instability and connectivity problems. Also Read I Microsoft outage: Outlook, Copilot and Teams remain disrupted, over 200,000 user issues reportedMicrosoft also clarified that the elevated load was not caused by an overall increase in user traffic. Instead, it was the unexpected unavailability of a large number of servers that created an imbalance across its infrastructure. The company has also been investigating a recent network configuration change that coincided with the beginning of the disruption, while testing alternative configurations to restore server stability. Why has Microsoft been unable to fix Outlook?Microsoft's initial recovery attempts have not produced the expected results. The company tried restarting affected servers, redistributing connection traffic across its global infrastructure and restricting certain types of traffic to reduce pressure on the affected systems. However, engineers found that some servers which had been brought back online became unresponsive again once traffic was redirected to them. This complicated efforts to restore services and meant that recovery had to be approached gradually. Microsoft subsequently acknowledged that its changes to improve service availability were not working as expected and said it was exploring alternative ways to increase capacity and stabilise the infrastructure. In its latest update, Microsoft said it had applied an upstream authentication and routing configuration component patch to a portion of its infrastructure. The company reported positive results in terms of server stability and said it was monitoring the changes before expanding them to additional servers supporting active regions. Is Outlook down because of a cyberattack?Microsoft has said it is not aware of any malicious activity causing the disruption. The company has explicitly said there is no indication of a cyberattack or malicious activity behind the incident. Its investigation has instead focused on server availability, authentication and routing-related infrastructure problems. Microsoft has promised to publish a detailed post-incident report once the disruption is fully resolved. The report is expected to explain the root cause and the additional measures being taken to prevent similar incidents. Which Microsoft services are affected by the outage?Although Outlook is among the most visibly affected applications, the disruption extends to several services that depend on Exchange Online and Microsoft's wider infrastructure. Users may be unable to access their Outlook mailboxes through the web, desktop or mobile applications. Email delivery may also be delayed. Microsoft Teams has also experienced disruptions, although its core messaging and meeting functions have largely remained operational. Calendar access, scheduling, invitations and certain chat-related features have been affected. Microsoft Copilot users may be unable to load Copilot Chat or receive responses. Access to workplace information, including emails, calendars and files, may also be disrupted. Some Microsoft 365 users may be unable to access recently used files or certain administrative features. Certain OneDrive and SharePoint features dependent on Exchange Online may also be affected, although access to files stored directly in SharePoint remains functional. Also Read I Microsoft working on ‘alternate workstreams’ as outage fix fails to deliver expected resultsMicrosoft Defender has also reported problems with some security features, including Safe Links, Safe Attachments and access to quarantine-related tools. Microsoft To Do and Planner users may encounter loading problems and failures while managing tasks and plans. The outage has also affected third-party services that depend on Microsoft's infrastructure, including tools that use Microsoft 365 connectors to access workplace information. When will Outlook be back up?Microsoft has not announced a definitive timeline for the complete restoration of Outlook and other affected services. The company is monitoring the performance of servers where fixes have been applied and gradually expanding its recovery measures. However, the repeated instability of servers after traffic is restored has complicated the process. Users may experience gradual improvements as Microsoft brings more infrastructure back online, but full recovery will depend on whether the company can restore server capacity and ensure that the affected systems remain stable under normal workloads. Follow the latest breaking news, major developments and agenda-setting stories from India and around the world with the newsdesk at Hindustan Times. Operating round the clock, the desk brings together experienced editors, reporters and correspondents to deliver fast, accurate and contextual reporting across subjects that influence public policy, governance, business, society and international affairs.
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