The new View Another Mailbox feature for the new Exchange admin center (EAC) lets you see and manage all mailboxes that you have permissions for from the new EAC.
[When this will happen:]
Worldwide and GCC: We began rolling out in late February 2024 expect to complete in late March 2024.
[How this will affect your organization:]
The new experience is more modern and easier to use, with a new design and faster performance.
We urge you to switch to this new EAC experience as soon as you can, as the old EAC experience will be deprecated mid-2024.
[What you need to do to prepare:]
Admins can access this new experience by clicking the ‘View another mailbox’ link.