Email Upon Workbook Opening

I hope this is not a violation of any of the security rules. At work, we are wanting to track when users open up a workbook by sending an email (not my idea). I have the email on open part working just fine, I wanted to know if there is an option that it does not save the sent message in the sent folder?

Private Sub Workbook_Open()
Run "EmailMacro"
End Sub
Sub EmailMacro()
Dim OutApp As Object
Dim OutMail As Object
Dim strbody As String
Set OutApp = CreateObject("Outlook.Application")
Set OutMail = OutApp.CreateItem(0)
strbody = "User xx has opened workbook" & vbNewLine & vbNewLine & _
"..." ...................