Microsoft 365 Alert – Service Degradation – SharePoint Online – Some users that are mentioned in list comments in SharePoint Online may not receive email notifications- RESOLVED

Announcements Shagufta Naaz

21/01/2026 15:15:00 AM

NHSmail Reference: INC46729860

Microsoft Reference: SP1220310

Issue Status: RESOLVED

Issue Description: Users that are mentioned in list comments in SharePoint Online may not receive email notifications.

Final Update: 26/01/2026 08:45:00 AM – Microsoft reversion of the offending change has completed its saturation process throughout the affected environment, and they have confirmed through an extended period of monitoring the service health telemetry that impact has been remediated.

Scope of impact: Impact is specific some users that are mentioned in list comments in SharePoint Online.

Root cause: A recent service change to remove a separate feature is causing impact.

Next Steps: Microsoft are continuing to analyze how the service change was partially applied to understand why the potential for impact wasn’t caught during the update testing and validation phase. These actions will help us to clarify what actions they can take to ensure similar impact doesn’t occur in future and to continue their ongoing mission to improve the resilience of their service for all SharePoint Online users.