Title: Some users can’t access their shared mailboxes through the “Open another mailbox” option in Outlook on the web
User impact: Users couldn’t access their shared mailboxes through the “Open another mailbox” option in Outlook on the web.
More info: A new window opened after selecting the option in Outlook on the web. However, once it was done loading, the contents of the new window showed the user’s personal mailbox items instead of the shared mailbox.
Some users reported that changing the URL in the pop-out browser window to outlook.office.com/(SharedMailboxEmail) works, or directly assigning access to users instead of groups bypassed this issue. Others reported that opening the shared mailboxes’ calendar and then going to the inbox also worked.
Final status: We’ve identified that a recent feature update changed how shared mailbox data was routed in Outlook on the web, resulting in impact. We’ve reverted this change and confirmed with previously impacted users that impact is remediated.
Scope of impact: Impact was specific to some users who were served through the affected infrastructure attempting to access their shared mailboxes through the Outlook on the web “Open another mailbox” option.
Start time: Tuesday, February 27, 2024, at 7:28 AM UTC
End time: Thursday, February 29, 2024, at 7:52 PM UTC
Root cause: A recent feature update changed how shared mailbox data was routed in Outlook on the web, resulting in impact.
Next steps:
– We’re reviewing the offending feature update to gather insight that may enable us to prevent similar impact in the future.
This is the final update for the event.
