E-commerce growth is driving the need for novel, more sustainable last-mile delivery strategies. One potential strategy is based on setting up a mobile-depot from where last-mile deliveries are conducted using cargo bikes. This research explores the impacts of this strategy through a microscopic traffic simulation based on a medium-sized European city. The strategy was evaluated at three levels: operational (route length and duration), energy consumption, and emissions. The results showed that adopting a last-mile delivery strategy based on a mobile-depot and cargo bikes leads to significant benefits in terms of energy consumption and emission, which decrease by more than 80 %, but imply lengthier (+49 %) and more time-consuming (+14 %) routes compared to a traditional parcel delivery strategy.