Me. Rev. Stat. tit. 1, § 505

All addressees on mailing lists used for the distribution of all matters printed or distributed at state expense by dedicated or undedicated revenues shall at least once in every 12-month period be contacted in writing to inquire if continuance of delivery to said addressees is desired. Failure of the addressee to affirmatively reply within 30 days of the written inquiry shall cause such addressees to be removed from said mailing list. However, nothing in this section shall prevent any printed matter being distributed where otherwise required by law.