Microsoft 365 Alert – Service Degradation – Exchange Online – Users may be unable to send email messages to Microsoft.com users and get an Non-Delivery Report (NDR) – RESOLVED

23/06/2023 08:58:00 AM (GMT)

NHSmail Reference : INC36570375

Microsoft Reference : EX602369

Issue Status : RESOLVED

Issue Description : Users may have been unable to send email messages to Microsoft.com users and got an NDR.

Final Update : 23/06/2023 08:58:00 AM – Microsoft has determined that a service update had affected a subset of service infrastructure that facilitates inbound email messages to the Microsoft domain. The update caused the subset of service infrastructure to drop below the manageable service performance thresholds, resulting in impact. After removing the affected subset of service infrastructure from service, they have internally validated that the issue is resolved.

Scope of impact : This issue affected any user that was attempting to send email to Microsoft.com users.

Root cause : A service update affected a subset service infrastructure that facilitates inbound email messages to the Microsoft domain, resulting in impact.

Next steps : Microsoft are further analyzing the offending service update to better understand why impact was produced and so they can help identify similar problems during out testing and validation processes.