Die eigentliche Frage ist doch, welches Object diese Eigenschaften bereitstellt und wie der Inspector Dir dabei hilft?

Ein Beispiel von mir aus einem anderen Forum (artverwandte Problemstellung):

Option Explicit

Private WithEvents oInspector As Outlook.Inspectors
Public WithEvents oEmail As Outlook.MailItem
Const sMailItem As String = "MailItem"


Private Sub Class_Initialize()
    On Error GoTo err
    Set oInspector = Outlook.Application.Inspectors
err:
If err.Number <> 0 Then
    MsgBox err.Number & vbCrLf & err.Description
    Resume Next
End If
End Sub

Private Sub oEmail_Forward(ByVal Forward As Object, Cancel As Boolean)
    If Not oEmail Is Nothing Then
        With oEmail
            If .Class = olMail Then
                If Not Forward Is Nothing Then
                    Forward.BCC = "Email weiterleiten"
                End If
            End If
        End With
    End If
End Sub

Private Sub oEmail_Open(Cancel As Boolean)
if not oEmail is nothing then
    With oEmail
        If .Size = 0 And .ReceivedTime - .SentOn = 0 And .Subject = vbNullString Then
            'Emailgrösse Ist 0 Byte
            'zusätzlich ist Empfangszeit minus Versandtzeit = 0
            'ausserdem, kein Betreff
            .BCC = "Neue Email"
        End If
    End With
End if
End Sub

Private Sub oEmail_Reply(ByVal Response As Object, Cancel As Boolean)
    If Not oEmail Is Nothing Then
        With oEmail
            If .Class = olMail Then
                If Not Response Is Nothing Then
                    Response.BCC = "Auf Email antworten"
                End If
            End If
        End With
    End If
End Sub

Private Sub oInspector_NewInspector(ByVal Inspector As Inspector)
    If TypeName(Inspector.CurrentItem) = sMailItem Then
        Set oEmail = Inspector.CurrentItem
    End If
End Sub

https://www.ms-office-forum.net/forum/showthread.php?p=1942598&highlight=inspector#post1942598

gruß

Marco