Administrative Litigation Act Article 62

Service of process shall be effectuated by an execution officer or post office delegated by the administrative court clerk.In cases of service effectuated by a post office, the relevant postman shall be deemed the person who effects service; the implementation rules shall be promulgated by the Judicial Yuan in collaboration with the Executive Yuan.
中文原文 行政訴訟法第62條
送達由行政法院書記官交執達員或郵務機構行之。
由郵務機構行送達者,以郵務人員為送達人;其實施辦法由司法院會同行政院定之。

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