When any application, report, statement, notice or any other document required to be filed by the provisions of Title 67, Chapter 66, Idaho Code has been deposited post paid in the United States mail properly addressed, it shall be deemed to have been received on the date of mailing. It shall be presumed that the date shown by the post office cancellation mark on the envelope is the date of mailing.
Idaho Admin. Code r. 34.03.01.012