Customs Act 1962

84. Regulations regarding goods imported or to be exported by post. - 

The Board may make regulations providing for -

(a) the form and manner in which an entry may be made in respect of goods imported or to be exported by post;

(b) the examination, assessment to duty, and clearance of goods imported or to be exported by post;

(c) the transit or transhipment of goods imported by post, from one customs station to another or to a place outside India.