The counter clerk will give you a certificate of posting which he has initiated with the date stamped.

柜台职员会给你一份他已经开始的并盖有日期戳的邮寄证明。

You should get a certificate of posting from the container in the post office and follow the instructions shown on the reverse.

你应该从邮局的集装箱里拿一张邮寄证明，并按照背面的指示去做。