coloque este vba no seu módulo thisoutlooksession
e ajuste suas configurações de macro adequadamente
Public WithEvents myOlApp As Outlook.Application
Public Sub Initialize_handler()
Set myOlApp = CreateObject("Outlook.Application")
End Sub
Private Sub myOlApp_ItemSend(ByVal Item As Object, Cancel As Boolean)
Dim prompt As String
prompt = "The BCC Field is empty!"
If Item.BCC = "" Then
If msgbox(prompt, vbYesNo + vbQuestion, "BCC Field") = vbNo Then
Cancel = True
End If
End If
End Sub