' <DieseOutlookSitzung>
Option Explicit
Private WithEvents ReplyButton As Office.CommandBarButton
Private WithEvents m_Inspectors As Outlook.Inspectors
Private m_Mail As Outlook.MailItem

Private Sub Application_Startup()
  Set ReplyButton = Application.ActiveExplorer.CommandBars.FindControl(, 354)
  Set m_Inspectors = Application.Inspectors
End Sub

Private Sub m_Inspectors_NewInspector(ByVal Inspector As Outlook.Inspector)
  On Error Resume Next
  If Not m_Mail Is Nothing Then
    m_Mail.Delete
    Set m_Mail = Nothing
  End If
End Sub

Private Sub ReplyButton_Click(ByVal Ctrl As Office.CommandBarButton, _
  CancelDefault As Boolean _
)
  On Error Resume Next

  If TypeOf Application.ActiveWindow Is Outlook.Explorer Then
    Set m_Mail = Application.ActiveExplorer.Selection(1)
  Else
    Set m_Mail = Application.ActiveInspector.CurrentItem
  End If
End Sub
' </DieseOutlookSitzung>