I would like to have a post box.

我想开一个邮政信箱。

youdao

'Snail mail' is the traditional letter delivering service in which you have a postman and a post box.

所谓的“蜗牛邮件”就是传统的邮寄信件，没有邮递员也没有邮箱。

youdao

He produced 1000 leaflets tagged with his phone number and a post office box number.

他做了一千份标有他的电话号码和邮箱号码的传单。

《柯林斯英汉双解大词典》

In the future, subscriptions can be delivered to a printer rather than a post box.

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Meanwhile a post box in St Peter's Road is proving to be a port in a storm.

BBC: Kensington post boxes sealed after postman loses keys

On 15 April, a further package, addressed to Mr McBride, was intercepted by Royal Mail staff at a post box on Montgomery Terrace, Kilwinning.

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