Upon receipt by the election commissioner or county clerk of a complete and correct registration application showing that the registrant is qualified to be a registered voter pursuant to sections 32-312.01 to 32-312.05, the registrant shall be a registered voter and the election commissioner or county clerk shall send, by nonforwardable first-class mail, an acknowledgment of registration to the registrant at the postal address shown on the registration application. If an acknowledgment of registration is returned as undeliverable, a second nonforwardable first-class mailing shall be attempted. If a registration application is a duplicate of a registration already on file, the registrant shall be so notified.