Some admins may be unable to make changes to distribution lists in Exchange Online and receive an error

Title: Some admins may be unable to make changes to distribution lists in Exchange Online and receive an error User impact: Admins may have been unable to make changes to distribution lists in Exchange Online and received an error. More info: Affected admins may have been unable to view, add, remove, or edit users associated with distribution lists in Exchange Online and received the following error message: "You don't have permission to access this page or perform this action". This issue affected both the Exchange admin center and the Microsoft 365 admin center. As a workaround, affected admins could’ve used the Exchange Online PowerShell cmdlet “Set-DistributionGroup” to manage distribution lists. Final status: We’ve 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. Start time: Sunday, July 12, 2026, at 11:00 PM UTC End time: Wednesday, July 15, 2026, at 1:00 AM UTC 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: - We’re reviewing our validation and updating procedures to better detect and prevent issues like this prior to deployment in the future. This is the final update for the event.

Title: Some admins may be unable to make changes to distribution lists in Exchange Online and receive an error User impact: Admins may be unable to make changes to distribution lists in Exchange Online and receive an error. More info: Affected admins may be unable to view, add, remove, or edit users associated with distribution lists in Exchange Online and receiving the following error message: "You don't have permission to access this page or perform this action". This issue affects both the Exchange admin center and the Microsoft 365 admin center. As a workaround, affected admins can use the Exchange Online PowerShell cmdlet “Set-DistributionGroup” to manage distribution lists. Current status: The process or reverting the offending service update is complete and we’re validating with affected users to ensure the issue is resolved as expected. 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 be impacted. Start time: Sunday, July 12, 2026, at 11:00 PM UTC 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 update by: Wednesday, July 15, 2026, at 9:30 AM UTC

Title: Some admins may be unable to make changes to distribution lists in Exchange Online and receive an error User impact: Admins may be unable to make changes to distribution lists in Exchange Online and receive an error. More info: Affected admins may be unable to view, add, remove, or edit users associated with distribution lists in Exchange Online and receiving the following error message: "You don't have permission to access this page or perform this action". This issue affects both the Exchange admin center and the Microsoft 365 admin center. As a workaround, affected admins can use the Exchange Online PowerShell cmdlet “Set-DistributionGroup” to manage distribution lists. Current status: Our rollback of the offending service update is still ongoing across affected regions and is taking longer than initially anticipated. We're discussing what actions we can take to expedite the rollback progress to remediate impact as soon as possible. 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 be impacted. Start time: Sunday, July 12, 2026, at 11:00 PM UTC 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 update by: Wednesday, July 15, 2026, at 3:00 AM UTC

Title: Some admins may be unable to make changes to distribution lists in Exchange Online and receive an error User impact: Admins may be unable to make changes to distribution lists in Exchange Online and receive an error. More info: Affected admins may be unable to view, add, remove, or edit users associated with distribution lists in Exchange Online and receiving the following error message: "You don't have permission to access this page or perform this action". This issue affects both the Exchange admin center and the Microsoft 365 admin center. As a workaround, affected admins can use the Exchange Online PowerShell cmdlet “Set-DistributionGroup” to manage distribution lists. Current status: We’ve determined that a recent update to distribution list management functionality inadvertently created a configuration conflict in a section of the service infrastructure, resulting in impact. We’re reverting the update to mitigate impact and initial indicators suggest that distribution list management functionality has been restored in West UK and West Japan regions. We’re continuing to deploy the fix across the remaining affected regions and expect deployment to be complete by our next scheduled 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 be impacted. Start time: Sunday, July 12, 2026, at 11:00 PM UTC 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 update by: Tuesday, July 14, 2026, at 11:00 PM UTC

Title: Some admins may be unable to make changes to distribution lists in Exchange Online and receive an error User impact: 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. Current status: We've identified that an API configuration conflict is affecting the permissions flow leveraged for distribution list administrative operations and resulting in impact. We're proceeding with further review of the impacted flow and details provided by affected users to determine our next steps towards remediation. Scope of impact: Any admins attempting to make changes to Exchange Online distribution lists through the Microsoft 365 admin center or Exchange admin center may be impacted. Next update by: Tuesday, July 14, 2026, at 10:30 AM UTC

Title: Some admins may be unable to make changes to distribution lists in Exchange Online and receive an error User impact: Admins may be unable to make changes to distribution lists in Exchange Online and receive an error. More info: Affected users report being unable to view, add, remove, or edit users associated with distribution lists in Exchange Online and receiving "Unauthorized" permissions errors, even when using global administrator accounts. Current status: We're investigating a potential issue with Exchange Online and checking for impact to your organization. We'll provide an update within 60 minutes.