Postal service is the cheapest. ZTO Express, starting price 10 yuan, and it must be within 2kg. If it exceeds 2 kg, 8 yuan will be charged for each excess 1 kg; Dayun Express starts at 8 yuan, but the first weight is only 1kg, and every time it exceeds 1kg, 6 yuan will be charged; The starting price of postal service is also 8 yuan, the first weight is 2kg, and the excess is only in 6 yuan. So the postal service is the cheapest. Postal service is a communication department managed by the state or directly engaged in delivering all kinds of mail (letters or articles), which has the characteristics of communicating officials, businessmen and people.