48.  (1) The Commission shall grant to the public postal licensee the exclusive right to provide private letter boxes or bags and postal services except in relation to -

(a) letters weighing more than three hundred and fifty grams;

(b) trade announcements, circulars, printed extracts from newspapers or advertisements not addressed to any particular person;

(c) letters delivered by an employee of the sender;

(d) letters delivered by a messenger employed by the sender especially for the purpose, not being a person employed or engaged in the course of his business or employment in delivering or procuring the delivery of letters;

(e) letters concerning goods sent with the goods and delivered therewith;

(f) letters carried to or from a post office;

(g) letters carried in accordance with an agreement entered with the public postal licensee;

(h) transfers between document exchanges;

(i) letters carried to the premises of a provider of electronic mail services for the purposes of being transmitted as electronic mail, or letters carried from the premises of such a person after having been transmitted;

(j) letters carried privately and delivered without hire, reward or other profit;

(k) letters carried and delivered personally by the sender; and

(l) letters, postcards, aerogrammes of three hundred and fifty grams or less in weight, if a charge of at least five times the basic charge of the public postal licensee letter rate for that class of item is made in respect of receiving, collecting, sending, despatching and delivery.

(2) If any question arises as to whether or not any postal article is a letter within the meaning of this Act, the decision of the Commission thereon shall be final.