Common law approaches to contract formation separate modes of communication into two distinct categories; instantaneous and non-instantaneous. This categorisation often relies on superficial differences drawn between them, namely the time taken between the dispatch and the receipt of a message. The categorisation has led to courts taking varied stances on how to determine when acceptance of an offer has taken place so as to become binding on the offer. While the postal rule has been considered the golden rule in cases where the contracting parties opted for the postal service, the increasing ubiquity of forms such as e-mail have sent the universality of the principle into question. A detailed analysis of e-mail demonstrates how the continued prominence of this classification is no longer tenable, and modified versions of the postal rule drawn from an international framework must be developed.