In AU's serviceportal you can require access for a shared mailbox
Insert the name or email address of the mailbox and click the search field. Name of mailbox owner will automatically appear.
You can choose two types of access:
An email will automatically be send to Mailbox Owner, who can approve or reject. You will be notified when Mailbox Owner has reacted.
When access has been approved you need to assign the shared mailbox to outlook
For removing an access to a shared mailbox, you need to contact your local IT-Support