Mich. Comp. Laws § 168.509x

Sec. 509x. An application for registration is considered received on or before the fifteenth day before an election if 1 of the following requirements is met: (a) An application is received at a department of state office, a designated voter registration agency, or the office of a county, city, or township clerk on or before the fifteenth day before an election. (b) An application is received through the mail that is postmarked on or before the fifteenth day before an election. (c) An application is received through the mail on or before the eighth day before an election, if the postmark is missing or is unclear and the application, on its face, is dated by the applicant on or before the fifteenth day before an election. The clerk shall consider an application received under this subdivision as received before the fifteenth day before an election. (d) An application is submitted electronically through the electronic voter registration interface on or before the fifteenth day before an election.