Regulation on the Electronic Exchange Operations of Official Documents of Government Agencies Article 13

If the recipient of an electronically exchanged official document is a private individual, a legal person, or unincorporated association, Article 6 to Article 8 do not apply; government agencies may as necessary for the sake of their operations separately adopt their own requirements.
中文原文 機關公文電子交換作業辦法第13條
受文者為人民、法人或其他非法人團體之機關公文,以電子交換行之者,得不適用第六條至第八條之規定,由各機關依其業務需要另定之。

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