Click on "File".

Click on "Add Account".

Type in the email address of the shared Mailbox and continue with connect.

Depending on various circumstances, the following login windows will look different.
Regardless of this, enter your own ETH Benutzername@ethz.ch and its password, activate >Save login data< or >Stay logged in<.
Now you may have to enter the OTP.
Then click on >Process completed<

- Complete this step by restarting Outlook.
Click on File - Account settings - Account settings...
Double-click on the mail address of the shared MBX, deactivate the cache and click Next - Done - Close.
Exit Outlook and restart it.
After that, the mailbox will appear on the left side under your mailbox with the email address as the name.