Millions of users around the world are facing a widespread outage in Microsoft 365 services, leading to disruptions in email access and interference with vital functions within Teams, Copilot, and other associated services. The technical issues began on Thursday, November 12, 2026, with the Downdetector platform recording approximately 130,000 reports of Outlook service disruptions in a short period, reflecting the scale of the global impact of this flaw.
Scope of impact and affected services
According to reports, the core of the problem is concentrated in the Exchange Online infrastructure. This flaw was not limited to the Outlook application alone but extended to include:
- Email access: Difficulties in opening mailboxes via Outlook (web, desktop, and mobile versions), in addition to delays in message delivery.
- Third-party applications: Accounts accessed via other applications such as Apple Mail were affected as a result of the flaw in Microsoft's underlying infrastructure.
- AI tools: AI services linked to Microsoft accounts faced difficulties, as the Copilot assistant may fail to retrieve emails, calendars, or work-related files.
- Productivity and collaboration: Microsoft detected issues with Planner, To Do, and some SharePoint functions, although files stored directly on SharePoint remain accessible.
- Microsoft Teams: The service is not completely down, but users are encountering errors when scheduling meetings, handling invitations, or editing calendar entries.
What is changing in practice?
This outage goes beyond the disruption of individual applications; the impact has extended to business operations and government systems, with Japan confirming a significant impact on its government IT systems. Technically, Microsoft has increased the "email timeout window" to 48 hours, a step aimed at protecting delayed messages and ensuring they are not lost while attempting to process data backlogs.
Regarding repair efforts, recent updates indicated an improvement in mailbox access in the Asia-Pacific region, and the company is currently working to expand these efforts to include other regions and increase system capacity. Microsoft confirmed that there is no evidence so far of any malicious activity or cyberattack behind this outage, but it has not set a final deadline for fully restoring the service stably in all regions.