Mich. Comp. Laws § 440.2856: Offer to make lease contract; manner of acceptance; lapse.

Sec. 2A206.

Unless otherwise unambiguously indicated by the language or circumstances, an offer to make a lease contract must be construed as inviting acceptance in any manner and by any medium reasonable in the circumstances.

If the beginning of a requested performance is a reasonable mode of acceptance, an offeror who is not notified of acceptance within a reasonable time may treat the offer as having lapsed before acceptance.