From Microsoft: “13 Nov 2026, 9:38 am NZDT
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.”
Mis à jour
Update
From Microsoft: “13 Nov 2026, 8:57 am NZDT
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.”
Mis à jour
Update
From Microsoft: “13 Nov 2026, 8:43 am NZDT
We’ve identified that affected servers are failing automated health checks, which is causing them to become unavailable, and this may be related to a recent change to a component involved in processing those checks. We’re testing a configuration change on a subset of affected infrastructure to address this and, if successful, will apply it more broadly. In parallel, we’ve initiated a restart of all affected servers and are validating whether they’re successfully returning to service.”
Mis à jour
Update
From Microsoft: “13 Nov 2026, 8:18 am NZDT
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.”
Problème signalé
Summary
Exchange Online mailboxes seem to be inaccessible. This appears to be a global issue.