Unless otherwise specified, service of a Notice of Hearing or any other document under this part must be effected by registered or certified mail, return-receipt requested, or by personal delivery. In the case of personal service, the person making service shall, if possible, secure from the party or other person sought to be served, or his or her agent, a written acknowledgement of receipt, showing the date and time of such receipt. If the person upon whom service is made declines to acknowledge receipt, the person effecting service shall execute a statement, indicating the time, place and manner of service, which shall constitute evidence of service.