The rapid growth of online purchasing on ecommerce platform has reinforced the requirement for efficient supply chain and logistics networks to meet increasing demands of customers with minimum costs. This research addresses the transportation problem in e-commerce logistics with the help of a mixed-integer linear programming (MILP) model to optimize the multi-group network of suppliers, distribution centers, and customers. The proposed model minimizes the total costs, including fixed costs for opening distribution centers and variable costs for transportation, while considering and satisfying the supply, demand, and capacity constraints. The proposed method efficiently determines the optimal locations for distribution centers and flow product allocations using MILP. The simulation using datasets of e-commerce network demonstrate cost savings compared to the baseline configurations represents robust performance under demand fluctuations. This research provides model for e-commerce system to design scalable and cost-efficient logistics networks.