Within three days after the filing of a Request for Notification of Intended Adoption or a Notice of Objection to Adoption and Intent to Obtain Custody with the putative father registry pursuant to sections 43-104.01 and 43-104.02, the Department of Health and Human Services shall cause a certified copy of such request or notice to be mailed by certified mail to the mother or prospective mother of such child at the last-known address shown on the request or notice or an agent specifically designated in writing by the mother or prospective mother to receive such request or notice.