email - Outlook 2010 - VBA MsgBox if more then 10 unread elements mails

I would like to start Outlook, then Outlook should only show ALL mailboxes, which have also unread emails.

At the moment, my VBA-Script expand all my mailbox folders / accounts.
But the list is unfortunately too long, now.

I am looking for a way to check unread elements.

I have tried it with a simple MsgBox, but does not work.

    Private Sub Application_Startup()
    'Folder-Variable definieren
    Dim objFolderIMAP01 As Outlook.Folder
    Dim objFolderIMAP02 As Outlook.Folder
    Dim objFolderIMAP03 As Outlook.Folder

    'IMAP-Folder zuweisen (hier in Klammern mit Anführungszeichen den Namen der IMAP-Datendatei eintragen)
    Set objFolderIMAP01 = Outlook.Session.Folders("MailBox1")

    Set objFolderIMAP02 = Outlook.Session.Folders("MailBox2")
    Set objFolderIMAP03 = Outlook.Session.Folders("MailBox3")

    'Alle Unterordner selektieren (und damit aufklappen)
    Call selectAllFolderRec(objFolderIMAP01)
    Call selectAllFolderRec(objFolderIMAP02)
    Call selectAllFolderRec(objFolderIMAP03)

    'Posteingang als Startordnder auswählen
    Call Outlook.ActiveExplorer.SelectFolder(objFolderIMAP01.Folders("Posteingang"))

    Call Outlook.ActiveExplorer.SelectFolder(objFolderIMAP02.Folders("Posteingang"))
    Call Outlook.ActiveExplorer.SelectFolder(objFolderIMAP03.Folders("Posteingang"))

    'Info wenn mehr als 10 Emails ungelesen
    If objFolderIMAP01.UnReadItemCount > 10 Then
        MsgBox "Mailbox 1 ist voll!"
    End If
    If objFolderIMAP01.UnReadItemCount > 10 Then
        MsgBox "Mailbox 2 ist voll!"
    End If

    If objFolderIMAP01.UnReadItemCount > 10 Then
        MsgBox "Mailbox 3 ist voll!"
    End If
End Sub

Sub selectAllFolderRec(objFolder As Outlook.Folder)
    Dim lngCounter As Long
    Dim bolSkipSelect As Boolean
    bolSkipSelect = False
    For lngCounter = 1 To objFolder.Folders.Count

        If objFolder.Folders(lngCounter).Folders.Count > 0 And objFolder.Folders(lngCounter).Folders.UnReadItemCount > 10 Then
            Call selectAllFolderRec(objFolder.Folders(lngCounter))
          Else
            If bolSkipSelect = False Then
                Call Outlook.ActiveExplorer.SelectFolder(objFolder.Folders(lngCounter))
                bolSkipSelect = True
            End If
        End If
    Next lngCounter
End Sub