Microsoft 365 Alert – Service Degradation – Exchange Online – Some users may be unable to sync contacts or receive notifications from third-party tools that use delegate access – RESOLVED

Announcements Habiba Tabasum

02/05/2024 08:50:00 AM

NHSmail Reference: INC42795452

Microsoft Reference: EX789514

Issue Status: RESOLVED

Issue Description: Users may be unable to sync contacts or receive notifications from third-party tools that use delegate access.

More Info: Impact includes, but isn’t limited to, a BlackBerry third-party tool which uses Exchange Web Services (EWS) to communicate with Exchange Online, in which the Exchange Online endpoint is returning ‘HTTP 500’ errors when Autodiscover is queried.

Final Update: 07/05/2024 08:53:00 AM – Deployment of Microsoft’s fix is complete, and they’ve determined from service telemetry that this issue is resolved.

Scope of impact: A portion of users utilizing third-party tools that use delegate access may be unable to sync contacts or receive notifications.

Root cause: A portion of EWS infrastructure which supports Autodiscover, contains a code regression which is causing the process of syncing contacts and retrieving notifications to fail for some users when utilizing a third-party tool that uses delegate access.

Next steps: Microsoft are continuing their investigation into the affected subset of infrastructure to determine how the regression was introduced and to better detect and prevent issues like this from occurring in the future.