The transferor’s delivery under section 55-2509, Idaho Code, of a property disclosure form as described under section 55-2508, Idaho Code, and the prospective transferee’s delivery under section 55-2509, Idaho Code, of an acknowledgement of his receipt of that form shall be made by personal delivery to the other party or his agent or subagent by ordinary mail or certified mail, return receipt requested or by facsimile transmission. For the purposes of the delivery requirements of this section, the delivery of a property disclosure form to a prospective cotransferee of residential real property or his or her agent shall be deemed considered delivered to other prospective transferees unless otherwise provided by contract.