Microsoft 365

FROM MICROSOFT - 16:00 Central

Current Status: We’re continuing to pursue all available pathways to restore service, as our actions taken thus far have not provided the anticipated relief. Our investigation has found that a core process on the affected servers is becoming overwhelmed, which causes the servers to stop responding and contributes to the capacity loss. To validate a potential recovery approach, we’re fully isolating a portion of our service infrastructure, restarting the affected components, and gradually reintroducing traffic to confirm our services remain stable before applying this approach more broadly. We’re also analyzing traffic patterns across our entire service infrastructure and evaluating whether isolating traffic within each region may allow affected regions to recover independently.

FROM MICROSOFT - 15:31 Central

“We’re continuing to work through restarting and validating the affected servers to safely return them to service, and we’re exploring opportunities to expedite this process. In parallel, we’re assessing whether reverting the small number of recent configuration updates we identified could help accelerate recovery.”

FROM MICROSOFT - 14:56 Central

Current Status: We’ve validated an alternative health check method on a subset of affected infrastructure, which allowed the servers in that subset to successfully return to service, and we’re now applying this change more broadly. We’re also preparing an automated recovery process to continually detect and restart unresponsive servers, to help keep them in service while this change progresses. Additionally, our review of recent changes has identified a small number of configuration updates that we’re investigating as potential contributors to the issue.

FROM MICROSOFT - 14:38 Central

Current status: While validating the targeted change, we found that many of the affected servers have become unresponsive, which is preventing us from confirming whether the change is effective. We’re restarting these servers so they can come back online with the change in place, and we’re applying the same approach to additional affected portions of our infrastructure to validate the results more broadly.

FROM MICROSOFT - 14:00 Central

Current status: While we haven’t identified any recent changes that correlate with the start of impact, our investigation indicates the failed health checks may originate from a specific component on the affected servers that’s responsible for processing them. We’re deploying a targeted change to bypass this component on a subset of servers to validate whether this restores availability, and we’ve taken steps to prevent additional servers from being removed from service while we work to return the affected servers to service. We’re also investigating why affected servers are experiencing elevated processor usage while handling requests.

FROM MICROSOFT - 13:35 Central
More info: Potentially impacted services include:

• Exchange Online
• Microsoft Teams
• SharePoint Online
• Microsoft Copilot 365
• Microsoft Defender XDR 

Current status: We’re aggressively pursuing all pathways to reduce impact. As a precaution, we’ve paused all deployments and configuration changes while we review recent changes for any correlation to this event. We’ve determined that the elevated load isn’t driven by an overall increase in traffic, but by a large number of servers being unexpectedly unavailable, which is shifting load onto the remaining infrastructure. We’re investigating what’s causing these servers to become unavailable while we work to safely return them to service.

Update From Microsoft - 13:15 Central

Current status: We’ve completed redistributing connection traffic across our worldwide infrastructure, and we’re moving additional traffic off the affected infrastructure to further reduce load. We’re also restarting affected servers to return them to service. In parallel, we’re investigating whether the elevated traffic reflects a genuine increase in requests or a shift in how traffic is being routed across our infrastructure.

From Microsoft at 12:45PM Central

We’ve identified a pattern in which affected servers are becoming intermittently unavailable, which places additional strain on the remaining infrastructure and contributes to the connectivity issues users are experiencing. We’ve begun redistributing Outlook connection traffic across our broader worldwide infrastructure to help balance the load, which may result in some latency while this change is in effect, and we’re reviewing recent changes to identify the source of the increased traffic.