Mont. Code Ann. § 76-16-111
What constitutes receipt of notice
76-16-111 . What constitutes receipt of notice. In all cases where notices are given to permittees under this chapter by certified mail and addressed to the post-office address of the permittee as shown by the records of the state district, the notices must be considered received by the permittee when deposited in the United States post office by the state district or by the commission.