Sub AddGroupMailbox()
    Dim objOutlook As Outlook.Application
    Dim objNamespace As Outlook.NameSpace
    Dim objRecipient As Outlook.Recipient
    Dim objMailbox As Outlook.Mailbox

    Set objOutlook = New Outlook.Application
    Set objNamespace = objOutlook.GetNamespace("MAPI")

    'Ersetzen Sie "GroupMailbox@example.com" durch die E-Mail-Adresse des Gruppenpostfachs
    Set objRecipient = objNamespace.CreateRecipient("GroupMailbox@example.com")
    objRecipient.Resolve

    'Überprüfen Sie, ob das Postfach gefunden wurde
    If objRecipient.Resolved Then
        Set objMailbox = objNamespace.GetSharedDefaultFolder(objRecipient, olFolderInbox)
        objMailbox.Display
    Else
        MsgBox "Das Gruppenpostfach konnte nicht gefunden werden."
    End If
End Sub