root\CIMV2:Win32_PerfRawData_SMTPSVC_SMTPServer\MessageBytesTotal

The total number of bytes sent and received in messages.

        Dim mc As ManagementClass
        Dim menge As ManagementObjectCollection
        Dim mo As ManagementObject
        Dim strTmp As String
 
        Try
            mc = New ManagementClass( _
              "\\MeinServer\root\cimv2:Win32_PerfRawData_SMTPSVC_SMTPServer")
 
            menge = mc.GetInstances()
 
            For Each mo In menge
                strTmp = mo("MessageBytesTotal")
            Next
            mc.Dispose()
            Return strTmp
        Catch ex1 As Exception
            console.writeline (ex1.Message)
        End Try