Microsoft Outlook Outage Explained: What Caused It, What Is Affected and Why Is It Taking So Long to Fix?

Microsoft is experiencing a major global outage that has disrupted Outlook, Teams and several other Microsoft 365 services. This has left users unable to access emails, calendars, and workplace tools. The disruption began on November 12 and has since continued into the following day, affecting individuals, businesses and government organisations across multiple countries, including India. The Redmond-based tech giant has attributed the problems to infrastructure and connectivity issues, but restoring normal service has proved more difficult than expected.

With recovery efforts continuing and some services showing signs of improvement, here is all you need to know about the Microsoft outage.

What Caused the Microsoft Outlook Outage?

Microsoft has been investigating a disruption that appears to involve a configuration change and an unexpected increase in traffic across its infrastructure. The company's initial updates hinted at elevated load on its systems, which caused some backend servers to become unavailable and affected connectivity across Microsoft 365 services.

With no fix in sight, the problem appears to have compounded as more servers became unavailable. This means traffic that would normally have been distributed across those machines was redirected to the remaining infrastructure, putting additional pressure on servers that were still operational. Microsoft says this ultimately created a situation in which the available capacity was unable to handle the redirected traffic reliably.

Recovery efforts have encountered difficulties as well. According to the company's updates, some servers that were brought back online stopped responding again after traffic was restored. In simple terms, increasing the number of available servers did not necessarily solve the problem, with the returning traffic placing additional pressure on the infrastructure.

Microsoft says engineers have been working on several fronts, including restricting traffic to affected infrastructure, rolling back certain software configurations, optimising traffic distribution, and increasing backend capacity. The company added that it will share more details in a post-incident report after the disruption is mitigated.

A recently patched Microsoft Outlook security vulnerability has also drawn attention amid the ongoing disruption. The vulnerability, tracked as CVE-2026-124194, is a spoofing flaw that affects Microsoft 365 Apps for Enterprise and Office LTSC 2021 and 2024. Microsoft addressed it through a security update included in its November Patch Tuesday rollout, covering supported versions of classic Outlook.

The company, however, has sought to rule out concerns about a cyberattack. In an update, Microsoft said it was not aware of any malicious activity causing the incident. It reiterated that it was treating the disruption as a priority while continuing to investigate the underlying cause.

Which Microsoft Services Are Affected by the Outage?

Microsoft Outlook is not the only service that is experiencing disruption. According to complaints on the company's forum, several apps and services within the Microsoft 365 ecosystem are dealing with connectivity problems, with the extent of the disruption varying between users.

The affected services include:

• Microsoft Outlook: Users have reported problems opening inboxes, sending and receiving emails, and accessing calendar information.
• Microsoft Teams: Some users have faced difficulties with chats, meetings and other workplace communication features, although access has varied.
• Microsoft Word, Excel and PowerPoint: Users have reported issues accessing Microsoft's online productivity applications.
• OneDrive and SharePoint: The disruption has also affected cloud storage and workplace collaboration services.
• Microsoft Copilot: Microsoft's AI assistant has experienced connectivity problems, with some features not working as expected.

In addition to the company's own suite of applications, the disruption has also impacted services that leverage Microsoft's infrastructure. OpenAI and Anthropic have reported problems involving their connections to Microsoft services, including Microsoft 365 connectors.

Downdetector, which tracks service disruptions through user-submitted reports, recorded nearly 1.3 lakh reports of Outlook problems at the peak of the outage on November 12, globally. Reports came from 74 countries and territories, including India. The figure has since fallen, although not all users have regained access. Gadgets 360 staff have been unable to access Outlook and other Microsoft services since the disruption began.

Why Is the Microsoft Outlook Outage Taking So Long to Fix?

One of the main complications appears to be that restoring affected servers does not guarantee that they will remain stable once normal traffic returns. Microsoft has said that some servers became unresponsive again after being brought back online. This has made it difficult to restore capacity in a straightforward manner. As traffic returns to previously affected infrastructure, the additional load can cause further instability, potentially prolonging the disruption.

The company has been attempting to address this by optimising traffic, restricting access to affected infrastructure and increasing available capacity.

Microsoft's updates on November 13 indicated some progress. The company said it was seeing positive results for service stability and increased capacity following its latest traffic optimisation measures. It was also extending these actions across affected regions while working towards a more sustained recovery.

However, Microsoft has not provided a definitive timeline for complete restoration. Its service health page continued to show service degradation for Microsoft 365 business and enterprise customers, as well as consumer products, in an update at 11:16am IST.

The latest update, added at 4:41pm IST, further explained that the company has made additional progress towards recovery. Microsoft is said to have completed actions across portions of affected infrastructure, while also gradually restoring traffic. It is witnessing improvements in key scenarios, including mailbox access and delayed email processing, though some intermittent issues may continue.