An offer is defined by Treitel as "an expression of willingness to contract on certain terms, made with the intention that it shall become binding as soon as it is accepted by the person to whom it is addressed", the "offeree". In addition, an offer is a statement of the terms on which the offeror is willing to be bound. When an offer has been made, it doesn’t means a contract has formed until the offeree accepts the offer.
The "expression" referred to in the definition may take different forms, such as a letter, newspaper, fax, email and even conduct, as long as it communicates the basis on which the offeror is prepared to contract.
Hence, an offer is a promise to do or not to do something which is made by an offeror to an offeree. It may only be accepted by a person who knows that it exists. Thus it can be sent by fax if the offeror had not specified a particular method of acceptance.
First, due to an offer can be expressed by several forms, which letter, newspaper, fax and emails are included. Thus, an offer send by fax is acceptable. Sending an offer by fax would help both offeror and offeree to save time and money, if it happens that both offeror and offeree are busy with something else important, then, sending the offer by fax would be the best way to deal with this problem. What’s more, offers send by fax are not easy to modify or do some correction, that’s the advantage of sending an offer by fax.
Second, according to the instantaneous communication, if the offeror has not stipulated a method of acceptance, the offeree may choose his own method. One method available to the offeree is instantaneous communication, for instance, telephone or other telecommunications such as fax. Via these, the offerees are able to see or hear the offer