Packages from Amazon will be showing up on doorsteps at unconventional times. Last October, the U.S. Postal Service launched a new policy of Sunday and holiday delivery in the mid-Michigan area as part of a two-year contract with Amazon. The service is available only to Amazon Prime members and products must be ordered two days ahead of time. The Mt. Pleasant Post Office handles all Sunday and holiday deliveries for its coverage area as well as Alma and Shepherd.