On November 12, 2026, Microsoft experienced a significant outage impacting Exchange Online and other Microsoft 365 services across North America, leaving many users unable to access their email and collaboration tools for several hours.
- Outage affected Exchange Online, Teams, SharePoint, and related services
- Issue caused by servers failing automated health checks, not cyberattack
- Microsoft actively balancing loads and restarting infrastructure to recover
What happened
Starting around 10:40 a.m. ET on November 12, Microsoft acknowledged issues affecting Microsoft Teams and Exchange Online users primarily in North America. Users reported problems accessing their email through multiple connection methods. By midday, Microsoft confirmed its network was experiencing elevated load across multiple regions caused by servers going offline, rather than from increased user traffic or external attack.
In response, Microsoft paused all ongoing deployments and began redistributing traffic across its wider global infrastructure. The company also restarted affected servers in an effort to restore service. Key impacted services included Exchange Online, Microsoft Teams, SharePoint Online, Microsoft Copilot 365, and Microsoft Defender XDR. Downdetector showed a sharp rise in outage reports from users, which gradually declined after Microsoft’s mitigation efforts.
Why it matters
Microsoft 365 services are deeply embedded in the workflows of businesses and enterprises across North America, making disruptions like this a significant impediment to daily operations. Email is a critical communication tool, and outages can delay information flow, disrupt meetings, hinder collaboration, and impact productivity on a large scale.
Cloud service outages are common but still pose a major risk given the scale of reliance on these platforms. While no cyberattack has been detected in this case, the outage adds to recurring concerns over the robustness and resilience of cloud infrastructure supporting essential business applications. It also highlights the necessity of having contingency plans for email and collaboration service failures.
What to watch next
Microsoft’s efforts to rebalance global server loads and reboot affected infrastructure will be critical to restoring full functionality. Watching for updates on the resolution timeline and any root cause identification will be important for enterprise IT teams and customers relying on Microsoft 365.
Additionally, it will be important to monitor if there are any recurring issues or follow-on service disruptions in the coming days. Microsoft’s handling of communication and transparency about the outage resolution process will also shape customer confidence moving forward in this high-dependency service environment.