The development of a sustainable postal system depends on the sustainability of its postal network, especially the organization of the postal access points. Postal service providers around the world face great challenges due to changes in the service trends and in consumer behavior. In this paper, the authors argue the importance of the postal network and its significance in rural areas. Methodologies including advanced search algorithms such as brute force and simulated annealing are proposed for best determining the possible locations of postal access points with no or minimal decrease in service accessibility. To the best of our knowledge, these algorithms are scarcely used for determining postal service accessibility. The results show that the decline of the postal office could significantly affect service accessibility. An analysis of the numbers of access points and their impacts on the postal network is provided, as well as the scenario of an additional access point. This methodology could help postal service providers to better plan network organization and resources. For service users, the application of the methodology adds to better service accessibility that considers the distances traveled.