1. Within twenty-one days of receiving a voter registration form completed under section 48A.7A, the commissioner shall send an acknowledgment to the registrant, in the manner provided in section 48A.26, subsections 2 through 5, as applicable, at the mailing address shown on the registration form. The acknowledgment shall be sent by nonforwardable mail.
 2. If the acknowledgment is returned as undeliverable by the postal service, the commissioner shall attempt to contact the voter by forwardable mail. If a response is not received from the voter within fourteen days after the notice is mailed, the commissioner shall change the status of the registration to inactive status and shall immediately notify the state registrar of voters and the county attorney.
 3. A county attorney receiving a notification pursuant to subsection 2 shall review the voter’s registration documents and other such information as may be necessary, and report the findings to the commissioner and state registrar of voters.