A’ offered ‘B’ through facebook to enter into a contract and ‘B’ accepted the offer. Is it a valid contract? The Contract Act, 1872 is silent regarding facebook, twitter, email or any other modern mode of communication.
If we analyse section 4 of The 1872 Act, it covers all modes of communications along with facebook, email. Section 4 signifies that “the communication of an acceptance is complete as against the proposer, when it is put in a course of transmission to him, so as to be out of the power of the acceptor and as against the acceptor, when it comes to the knowledge of the proposer”. Here it is said to put in a course of transmission but no specific transmission is mentioned; so it includes all kinds of transmissions even email and facebook. Though email or facebook communication is within the purview of section 4, no specific rule is constituted whether postal rule or rule of instantaneous communication will be considered same as email and facebook contract.
If someone sends a message through facebook or email and opposite party replies instantly it seems to be instantaneous communication. In contrast, if a person sends a message through email or facebook-chat messenger but opposite party does not reply instantly; then it seems to be non-instantaneous communication in nature. Analysing the nature of email and facebook communication, it deems to be instantaneous as well as non-instantaneous communication.
Now, the question arises what rule of communication should be applied, whether rule of instantaneous communication or postal rule? India and USA constituted separate acts i.e. The Information Technology Act, 2000 and Uniform Electronic Transactions Act (UETA) respectively wherein they follow no rule of instantaneous communication or postal rule. In India, pursuant to section 13 of The Information Technology Act, 2000, the dispatch of an electronic record occurs when it enters a computer resource outside the control of the originator and the receipt would occur in the case of e-mail when the message enters the addressee’s electronic mailbox; so contract is complete when the message enters into the addressee’s mailbox. In USA, the contract is complete when the message enters an information processing system designated by the recipient for receiving such message. Both the countries do not follow rule of instantaneous communication and postal rule.
But what law should be followed in Bangladesh? In pursuance of the Entores Ltd v Miles Far East Corpn  EWCA Civ 3, if we categorise email or facebook communication as instantaneous communication i.e. telex, telephone, fax; the contract is complete when it comes to the knowledge of the proposer. If the proposer does not hear the acceptance for chaos or noise the contract is not completed. Alternatively, if we follow postal rule in email or facebook contract the contract is complete as soon as the email or message is sent. Though under Bangladeshi law the contract is complete when the acceptance comes to the knowledge of the proposer, the common practice is we follow English law Under Kmisetti Subbiah v Katha Venkataswamy  and contract is complete when the acceptance is posted.
Considering the nature of facebook and email communication we should apply rule of instantaneous communication as well as postal rule as it is mentioned earlier that nature of instantaneous communication and postal rule are existed in these modern modes of communications. When the nature of initiation of negotiation is instant, the instantaneous communication should be applied whatever the nature of completion of the negotiation and contract is complete when acceptance comes to the knowledge of the proposer. But when the nature of negotiation is not instant, the postal rule should be applied and the contract is complete when the acceptance is sent and gone beyond the control of the acceptor. If it is instant nature the offerer has option to revoke the contract before the acceptance coming to his knowledge and in non-instant contract, the offeror has enough time to revoke the proposal before the acceptance is sent.
To have a more effective and reliable communication rules, we need to implement a specific law to resolve disputes arising out of the contract made by modern modes of communications.