Get exchange Mail message form shared mailbox

Hi,
I am having issues trying to get mails from a shared inbox.
These are my properties in Get Exchange Mail Messages (SharedMailbox is filled like: xyz@domain.de):

And this is my mail folder structure:

postfach

When I try to get Mails from my main Inbox everything works perfectly fine.

What am I doing wrong?
The error code is: The SMTP address has no mailbox associated with it.