Some users’ quarantine notifications may not be received in their configured mailbox language in Exchange Online

Title: Some users’ quarantine notifications may not be received in their configured mailbox language in Exchange Online

User impact: Users’ quarantine notifications may not have been received in their configured mailbox language in Exchange Online.

More info: Affected users may have incorrectly seen that all quarantine notifications were being received in English when their mailbox has a different language configured.

Final status: Deployment of the fix is complete, and we’ve monitored service health telemetry to confirm that quarantine notifications are now received in the correct language and impact is remediated.

Scope of impact: Impact was specific to some users with quarantine notifications enabled who were served through the affected infrastructure.

Start time: Thursday, March 21, 2024, at 1:00 PM UTC

End time: Monday, April 15, 2024, at 8:00 AM UTC

Root cause: A recent service update to the code base responsible for identifying the user’s language when sending quarantine notifications introduced a code regression that led to impact.

Next steps:
– We’re reviewing our Exchange Online update procedures pertaining to the code base responsible for identifying users’ language configurations to prevent similar impact in future updates.

This is the final update for the event.