known, had the addressee exercised reasonable care or used any agreed procedure, that the data message was a duplicate. Section 19 In the case where an acknowledgement of receipt of a data message is required whether at the request of the originator or as agreed with the addressee before or at the time of sending such data message or as appeared in that data message, the following rules shall apply: (1) where the originator has not agreed that the acknowledgement be given in a particular form or by a particular method, an acknowledgement may be given by any communication by the addressee, whether by an automated information system or by any other method, or by any conduct of the addressee sufficient to indicate to the originator that the addressee has received the data message. (2) where the originator has stated a condition that the data message shall be regarded as having been sent only upon receipt of an acknowledgement by the addressee, it shall be deemed that the data message has never been sent, until the originator has received the acknowledgement. (3) where the originator has not stated such a condition under paragraph (2) and the originator has not received the acknowledgement within the time specified or agreed or, if no time has been specified or agreed, within a reasonable time, the originator: (a) may give notice to the addressee stating that no acknowledgement has been received and specifying a reasonable time by which the acknowledgement must be made by the addressee; and (b) if the acknowledgement is not received by the originator within the time specified in subparagraph (a), may, upon notice to the addressee, treat the data message as though it had never been sent, or exercise any other rights it may have. Section 20 Where the originator receives the addressee’s acknowledgement of receipt it is presumed that the related data message was received by the addressee. That presumption does not imply that the data message received by the addressee corresponds to the data message sent by the originator. Section 21 Where the received acknowledgement states that the related data message received by the addressee met the technical requirements, either agreed upon by the originator and the addressee or set forth in the applicable standards, it is presumed that those requirements have been met. Section 22 The dispatch of a data message is deemed to occur when such data message enters an information system outside the control of the originator. Section 23 The receipt of a data message is deemed to occur from the time when such data message enters an information system of the addressee. If the addressee has designated an information system for the purpose of receiving data message specifically, it shall be deemed that the receipt of a data message occurs at the time when the data message enters the designated information system. However, if such data message is sent to an information system of the addressee that is not the designated information system, it shall be deemed that the receipt of a data message occurs at the time when the data message is retrieved from that information system. www.ThaiLaws.com 5