Standard for Popularized Delivery Services Article 5

Chunghwa Post shall set up a total of not less than 8,000 pieces of dedicated equipment for collecting items throughout the country.The dedicated equipment for collecting items as mentioned in the preceding paragraph refers to the mailboxes, letterboxes or other special equipment for collecting documents or articles set up by Chunghwa Post.
中文原文 遞送普及服務標準第5條
中華郵政公司應於全國設置收受物件專用器具,其總數不低於八千個。
前項所稱收受物件專用器具,係指中華郵政公司所設信箱、信筒或其他收受文件或物品專用器具。

English translation for reference only; the Chinese text prevails. Not legal advice.