Microsoft 365 Alert – Service Degradation – Exchange Online – Some users may encounter Non-Delivery Report (NDR) failures when sending or receiving email messages – ONGOING

17/03/2025 08:37:00 AM

NHSmail Reference: INC46476230

Microsoft Reference: EX1030895

Issue Status: ONGOING

Issue Description: Some users may encounter NDR failures when sending or receiving email messages in Exchange Online.

More info: Microsoft expect the impact to be mitigated for a majority of our users; however, they remain focused on ensuring this incident is fully resolved.
Users may receive a Non-Delivery Report (NDR) containing an error stating “554 5.6.0 Corrupt message content”.

Current Update: 18/03/2025 07:42:00 AM – Microsoft have confirmed that the deployment of the fix is progressing as expected. In parallel, they have exhausted manual efforts to safely expedite the deployment and expect the remaining affected infrastructure to take an extended period to complete. They still remain confident that a majority of the impact has been mitigated. If your organization continues to see high impact related to this event, please work with your support representative to gather the relevant diagnostic data so they may explore avenues to address the impact being experienced.

Scope of impact: Some users serviced by the impacted portion of infrastructure sending or receiving email in Exchange Online may be affected, although impact is limited to a small subset of messages.

Next update by: Wednesday, March 19, 2025, at 3:00 PM UTC