          <p>
                    The buffers containing the message part to send. The implementation
                    will make copies of this object as needed, but ownership of the
                    underlying memory is not transferred. The caller is responsible
                    for ensuring that the memory locations pointed to by buffers
                    remains valid until the completion handler is called.
                  </p>
                </td>
</tr>
<tr>
<td>
                  <p>
    