(1) An electronic message is that of the originator if it is sent by the originator himself.
(2) As between the originator and the addressee, an electronic message is deemed to be that of the originator if it is sent by—
(a) a person who has the authority to act on behalf of the originator in respect of that electronic message; or
(b) an information processing system programmed by, or on behalf of, the originator to operate automatically.
(3) As between the originator and the addressee, the addressee is entitled to regard an electronic message as being that of the originator, and to act on that presumption, if—
(a) the addressee properly applies an authentication method agreed between the originator and the addressee for ascertaining whether the electronic message was that of the originator; or
(b) the electronic message as received by the addressee resulted from the actions of a person whose relationship with the originator or any agent of the originator enabled that person to gain access to an authentication method used by the originator to identify electronic message as its own.
(4) Subsection (3) does not apply if—
(a) the addressee has received a notice from the originator that the electronic message is not that of the originator and has reasonable time to act accordingly; or
(b) the addressee knew or should have known that the electronic message was not that of the originator had he exercised reasonable care or used any authentication method agreed between the originator and the addressee.