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Microsoft's Outlook and Exchange Online services went down for business and consumer users on November 12, 2026, beginning around 12:20 to 1 PM ET, according to several outlets. Microsoft attributed the problem to a large number of servers becoming unexpectedly unavailable, which pushed load onto the remaining infrastructure. As of about 6 PM ET, full restoration had no estimated time.
Key facts
- Reports on Downdetector began between about 12:20 and 1 PM ET. TechRadar saw a peak of more than 131,000 Outlook reports.
- Microsoft's status account pointed to Exchange Online issues in the Americas under incident EX1550543, per Android Authority. The Verge reported later updates describing multiple regions.
- Affected services include Exchange Online, Teams, SharePoint Online, Copilot 365 and Defender XDR, according to Engadget. Around 5 PM ET, Planner, To Do, Intune, Defender for Office 365 and Purview were added.
- TechCrunch reported that consumers also lost access to OneDrive and Office for the web.
- Microsoft had paused all deployments and configuration changes while it reviewed recent changes.
What Microsoft has said about the cause
Microsoft's early notes described "elevated load" on infrastructure across multiple regions. A later update, quoted by XDA, said the load was not driven by an overall traffic increase. Instead, a large number of servers were unavailable, shifting load onto the rest.
Engadget quoted a later status message saying a core process on the affected servers was becoming overwhelmed, causing them to stop responding. The same message said earlier actions had not delivered the expected relief.
Microsoft communications director Ben Hope said in a statement, as reported by The Verge, that the company was investigating issues primarily with Exchange Online.
Recovery efforts
According to XDA, which updated at 3:31 PM EST, Microsoft validated an alternative health check method on a subset of servers, allowing them to return to service, and began applying it more broadly. It also prepared an automated process to detect and restart unresponsive servers. The company said it was investigating a small number of configuration updates as possible contributors.
By about 6 PM ET, The Verge reported, Microsoft had begun returning some servers to service and shifting traffic to alternative pathways, with limited recovery in some regions. It warned that users may see gradual recovery as clients reconnect.
Why it matters
The outage hit email, collaboration, security and AI tools at once, and organizations including universities lost access to entire email systems, TechRadar reported. Microsoft's own status page and admin center were also hard to reach for some, which limited how administrators could follow updates. TechCrunch noted Microsoft pointed users to X instead.
It also follows a days-long Microsoft 365 outage in September, which Microsoft blamed on a "core authentication configuration" issue, TechCrunch reported.
