Microsoft 365 Alert – Service Degradation – Exchange Online – Some admins may be unable to make changes to distribution lists in Exchange Online and receive an error – RESOLVED

Announcements Sharmista Mohanta

14/07/2026 08:47:00 AM

NHS.net Connect Reference: INC46878558

Microsoft Reference: EX1426934

Issue Status: RESOLVED

Issue Description: Admins may be unable to make changes to distribution lists in Exchange Online and receive an error.

More info: Affected admins report being unable to view, add, remove, or edit users associated with distribution lists in Exchange Online and receiving “Unauthorized: You don’t have permission to access this page or perform this action” permissions errors, even when using global administrator accounts. This affects both the Exchange admin center and the Microsoft 365 admin center.

Final Update: 15/07/2026 08:49:00 AM – Microsoft has confirmed with affected users that this issue is resolved as a result of our reverting the offending service update.

Scope of impact: Some admins attempting to modify Exchange Online distribution lists through the Microsoft 365 admin center or Exchange admin center that are served by the affected infrastructure in the West UK, West Europe, India, Southeast Asia, West Japan, or East Australia regions may have been impacted.

Root cause: A recent update to distribution list management functionality inadvertently created a configuration conflict within a subset of the service infrastructure, resulting in impact.

Next steps: Microsoft is reviewing their validation and updating procedures to better detect and prevent issues like this prior to deployment in the future.