Private Sub TestCDO()
  Private Const PR_SMTP_ADDRESS = &H39FE001E
  Private Const PR_EMS_AB_PROXY_ADDRESSES = &H800F101E

  Dim olMail As Object
  Dim objSession As MAPI.Session
  Dim objMessage As MAPI.Message
  Dim objField As MAPI.Field
  Dim FlagVal As String
  Dim FVal As Variant
  
  Set objSession = CreateObject("MAPI.Session")
  objSession.Logon "", "", False, False,  0 
  
  For Each olMail In Application.ActiveExplorer.Selection
    If LCase(TypeName(olMail)) = "mailitem" Then
      Set objMessage = objSession.GetMessage(olMail.EntryID)
      Debug.Print (objMessage.Subject)

      FlagVal = ""
      If LCase(objMessage.Sender.Type) = "smtp" Then
        FlagVal = objMessage.Sender.Address
      Else
        For Each objField In objMessage.Sender.Fields
          If (objField.ID = PR_SMTP_ADDRESS) And (FlagVal = "") Then FlagVal = objField.Value
          If (objField.ID = PR_EMS_AB_PROXY_ADDRESSES) And (FlagVal = "") Then
            For Each FVal In objField.Value
              If InStr( 1 , LCase(FVal), "smtp:") >  0  Then FlagVal = Right(FVal, Len(FVal) - InStr( 1 , LCase(FVal), "smtp:") -  4 )
            Next
          End If
        Next
      End If
      Debug.Print (FlagVal)
    End If
  Next
End Sub

Private Sub TestRDO()
  Const PR_SMTP_ADDRESS = &H39FE001E
  Const PR_EMS_AB_PROXY_ADDRESSES = &H800F101E
  Dim olMail As Object
  Dim objSession As RDOSession
  Dim objMessage As RDOMail
  Dim FlagVal As String
  
  Set objSession = CreateObject("Redemption.RDOSession")
  objSession.MAPIOBJECT = Application.Session.MAPIOBJECT

  For Each olMail In Application.ActiveExplorer.Selection
    If LCase(TypeName(olMail)) = "mailitem" Then
      Set objMessage = objSession.GetMessageFromID(olMail.EntryID)
      Debug.Print (objMessage.Subject)

      FlagVal = ""
      If LCase(objMessage.Sender.Type) = "smtp" Then
        FlagVal = objMessage.Sender.Address
      Else
        FlagVal = objMessage.Sender.Fields(PR_SMTP_ADDRESS)
        If FlagVal = "" Then FlagVal = objMessage.Sender.Fields(PR_EMS_AB_PROXY_ADDRESSES)
      End If
      Debug.Print (FlagVal)
    End If
  Next
End Sub