You use First Middle of the Last family. The clerk of court will only issue process to First Middle. The Receipt will be First Middle or sometimes MIDDLE V. LAST.
Once you are a court of competent jurisdiction you adjudicate the mail as suits against you. If you are receiving mail to First Middle Last then you likely gave somebody that name as if it was you. Over time, that will stop happening except where you have chosen to be the trustee for it.