Microsoft 365 Issues Reported

Microsoft Update: Microsoft has made additional progress towards recovery, with actions now completed across portions of affected infrastructure and traffic being restored. We're seeing improvements in key scenarios, including mailbox access and delayed email processing, though some intermittent issues may continue. Our focus is extending these recovery actions across remaining affected infrastructure while continuing stabilization and adding capacity to improve consistency.

Current status: We’ve monitored the status of the changes applied to improve serviceability and confirmed that change is not taking as expected. We’re identifying alternate workstreams that can be applied to increase capacity in the face of sustained traffic management imbalances.

Current status: We’re applying infrastructure capacity improvements where possible in an effort to help support traffic in regions coming online. We’re continuing to monitor the results of changes applied so we can identify strategic actions that can help to improve service health across all affected regions.

Current status: Our investigation has found that a process on the affected servers responsible for establishing secure connections becomes overwhelmed, causing the servers to stop processing requests. We're preparing a configuration change to address this behavior that can be applied across all affected servers, and we're validating it on a subset of servers before applying it more broadly alongside restarts of the affected infrastructure. In parallel, we've begun reverting a recent network configuration change that correlates with the start of impact and are monitoring to determine whether this contributes to recovery. The temporary traffic limitations we previously described are now in effect in specific locations. We're monitoring the affected servers in those locations to confirm whether they remain stable while handling a narrower set of connections, after which we'll gradually reintroduce additional traffic.

Current status: While the servers we've returned to service initially remain healthy, we've observed that they can become unresponsive again once they begin receiving traffic; we're analyzing diagnostic data to determine what's triggering this behavior. In parallel, we're temporarily limiting which types of traffic can reach the affected infrastructure in specific locations.

Additionally, we're rebuilding a subset of affected servers using a previous software configuration to validate if this prevents them from becoming unresponsive. More info under EX1550543 and MO1550821 in the Microsoft 365 admin center, as well as status.cloud.microsoft if the admin center is not available to you.

Current status: We've begun returning a portion of the affected servers to service, and they're remaining stable so far. We’ve also shifted traffic and connections to alternative pathways wherever possible and have observed limited recovery in some regions.

Microsoft 365 Update:
We've validated an alternative service health check method, which allowed a subset of affected servers to successfully return to service. We're now applying this change more broadly. We're also preparing automated recovery systems to continually detect and restart unresponsive servers, to maintain service stability while this change progresses. More info under EX1550543 and MO1550821 in the Microsoft 365 admin center, as well as status.cloud.microsoft if the admin center is not available to you.

Update: Microsoft status- testing a configuration change to address a problem that's causing servers to fail automated health checks and become unavailable. In parallel, they've initiated a restart of all affected servers and are monitoring health as they return to service. More info under EX1550543

Information Technology Services (ITS) is aware of an issue affecting some Microsoft 365. They are currently investigating an issue impacting multiple Microsoft 365 services and determined the affected infrastructure is experiencing elevated load across multiple regions, which is likely contributing to the connectivity errors.

Microsoft engineers began redistributing connection traffic across global infrastructure to balance the load and recover services. They will update the outage status once the outage is repaired.

Updates will be posted here as they become available.

Internal USO Services - USO Microsoft 365