Mich. Comp. Laws § 168.478

Sec. 478. At the time of filing a petition proposing a constitutional amendment, an initiated law, or a referendum, the person or persons filing the petition may request a notice of the approval or rejection of the petition to be forwarded to the person or persons or any other persons designated at the time of the filing of the petition. If a request is made under this section, the secretary of state shall, immediately upon the determination of the sufficiency or insufficiency of the petition, transmit to the person or persons notice of the determination of the sufficiency or insufficiency of the petition.