Microsoft Outlook outage: Efforts underway to restore Outlook, Teams and Copilot; when will services return?

Microsoft is exploring alternative ways to restore its services as the company continues to battle a widespread disruption affecting Outlook, Teams, Copilot and several other Microsoft 365 services. Microsoft's initial recovery measures failed to deliver the expected results.

In a post on X, the company said it had monitored the changes introduced to improve service availability but found that they were not working as expected. Microsoft is now identifying alternative measures to increase infrastructure capacity amid continuing traffic-management imbalances.

It is also working to increase infrastructure capacity, adjust network traffic and investigate why its servers are struggling to handle incoming connections.

Quick answers to key questions

•5 QUESTIONS

1

When will Outlook, Teams and Copilot be fully restored?⌵

Microsoft has not announced a timeline for complete restoration. Some regions have seen partial recovery, but the company says its recovery measures have not yet delivered the expected improvement.

2

What is causing the Microsoft 365 outage?⌵

Microsoft reported that affected servers were under elevated load and some were becoming unresponsive. It also identified difficulties routing requests between backend machines and traffic imbalances during recovery efforts.

3

What is Microsoft doing to fix the Outlook and Teams outage?⌵

Microsoft is increasing infrastructure capacity, scaling up virtual machines and adjusting network traffic. It is also investigating backend systems and trying to restore servers that are stuck in an unstable state.

4

Which Microsoft 365 services and features are affected by the outage?⌵

The disruption affects Outlook and Exchange Online, Teams calendar and meeting scheduling, and Microsoft 365 Copilot Chat. Some SharePoint, Defender, Planner, To Do, Purview, Power BI and Fabric functions are also affected, but not every feature.

5

What problems are Outlook and Teams users experiencing?⌵

Outlook users have reported trouble accessing mailboxes and delays in email delivery. Teams calendar and meeting-scheduling functions have been affected, while joining meetings, group chats and channel messages have largely remained functional.

In an update on its website, Microsoft said it had observed a surge in outbound call volumes from its routing services to backend servers following the mitigation measures introduced to restore services. The increase was linked to difficulties in routing requests between backend machines, alongside traffic-rebalancing measures implemented during the outage.

"We're continuing to observe heightened volume due to traffic rebalancing actions that we have taken throughout this event," Microsoft said in its service-health update.

Microsoft is increasing the capacity of its infrastructure by scaling up virtual machines to reduce the load on affected servers. It is also examining traffic flows and backend systems to identify the reasons behind the surge in network requests.

The company is attempting to fix servers that have become stuck in an unstable state and is trying to force-sync a recent network change to improve service availability. However, Microsoft said some machines were not responding as expected, preventing the changes from syncing successfully.

In an earlier update, the company said it had adjusted traffic protocols, redistributed connections and introduced strategic traffic-blocking measures. These steps had resulted in partial recovery in some regions, but the improvement was not sustained.

The disruption extends beyond Outlook and Exchange Online, affecting several applications and features across Microsoft's workplace ecosystem.

Outlook users have reported problems accessing mailboxes and delays in email delivery. In Microsoft Teams, calendar and meeting-scheduling functions have been affected, although core features such as joining meetings, group chats and channel messages have largely remained functional.

Microsoft 365 Copilot Chat has also experienced problems loading or responding. SharePoint Online users have faced issues with features dependent on Exchange Online, although direct access to stored files has remained functional.

The disruption has also affected certain Microsoft Defender security features, along with applications such as Planner, To Do, Purview, Power BI and Microsoft Fabric. Some functions involving task operations, security portals, data protection and the export of sensitivity-labelled reports have been affected.

Microsoft has clarified that the disruption does not affect every feature within these services.

The company is tracking the incidents under two references: EX1550543, covering Exchange Online mailbox connectivity, and MO1550821, covering multiple Microsoft 365 services.

Microsoft has not announced a timeline for the complete restoration of affected services.

Although some regions have experienced partial recovery, the company has acknowledged that its measures have not resulted in improvements. It is continuing to monitor its infrastructure and implement additional capacity and traffic-management measures.

Prabhakar Jha is a journalist and digital news editor with nearly a decade of experience in online media, specialising in breaking news, politics, national affairs. Having built his career across fast-paced digital newsrooms, he has developed a reputation for delivering accurate, timely, and reader-friendly stories while leading editorial teams during high-pressure news cycles. In 2026, he joined LiveMint as a Digital Content Producer. <br><br> A postgraduate in History from the University of Delhi, Prabhakar combines strong editorial judgment with a keen interest in public policy, governance, economics, and global affairs. Before joining LiveMint, he worked with leading digital publications, including News9Live and The Times of India, where he handled breaking news, copy editing, headline writing, live coverage, and newsroom coordination. <br><br> Beyond the newsroom, Prabhakar is passionate about long-form writing and storytelling. He has a particular interest in global affairs. An avid reader with a love for literary fiction, he also enjoys blogging, poetry, and working on creative writing projects.

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