If Not CreateObject("Scripting.FileSystemObject").FileExists(strFullPath) = _
  True Then
    Error 1002
End If
 
'Save file
myMailItem.SaveAs strFullPath, vExtConst
 
Set objFile = CreateObject("DSOFile.OleDocumentProperties")
objFile.Open(strFullPath)
 
objFile.SummaryProperties.Author = EXM_OPT_SENDER
objFile.Save