Microsoft 365 Alert – Service Degradation – Exchange Online –Users may be unable to view or access some public folders within the Outlook desktop client and Outlook on the web – RESOLVED

Announcements Arpan Das

01/04/2025 07:48:00 AM

NHSmail Reference: INC46491030

Microsoft Reference: EX1042577

Issue Status: RESOLVED

Issue Description: Users may be unable to view or access some public folders within the Outlook desktop client and Outlook on the web.

More info: Additionally, affected users may be unable to create new or delete some existing public folders within the Outlook desktop client and Outlook on the web.

Final Update: 09/04/2025 08:59:00 AM – Microsoft have determined that their sync process is complete and their monitoring confirms that this issue is resolved.

Scope of impact: Impact is specific to some users who are served through the affected infrastructure.

Root cause: A framework change is causing an increase in connection limit exceeded errors and public folder hierarchy sync failures, which is resulting in impact.

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