Inspired by the real-world case of the urban area a Bologna, northern Italy, and targeting the United Nations SDG-11 - Sustainable Cities and Communities, this paper focuses on the high impact logistic problem of the last-mile delivery of products in urban areas, generalizing, modeling using linear programming, and exemplifying the strategic and tactical design of an urban logistic network for last-mile deliveries using intermediate lockers as transit points and the crowd as a key mobility vector next to traditional professional drivers. The goals to reach and best balance are both economic and environmental, while the final purpose and implication is contributing to the long-term urban sustainability transition by assessing the feasibility and convenience of promoting ‘hybrid’ last-mile delivery networks mixing professional carriers and private people, as the crowd, with potential benefit for the end-users, the local communities and the society as a whole. Results for the urban area of Bologna showcase the feasibility and convenience of this potentially disruptive delivery system.