You have to pay a premium for express delivery.

寄快速投递你得付额外费用。

Please transmit the stock certificates by special messenger.

请通过特种邮件投递将股寄来。

In case of non-delivery, return to (the) sender.

(邮件用语)无法投递时, 回原处。

The postman delivers letters.

邮递员投递信件。