Patent ID: 8150927

Claim:
A method for processing messages to be transferred from a transmitting entity to a receiving entity over a communication network, the method comprising the steps of: at the transmitting entity obtaining from a sender's email client a multipart message containing text and attachments, addressed to a recipient; defining a substantially unique identifier for an attachment; comparing the substantially unique identifier to the identifiers previously stored in a memory, concluding that the attachment has not been previously transferred to the receiving entity when the substantially unique identifier is missing in the identifiers stored, selecting a base attachment with the related identifier which are known to be available for the receiving entity, calculating a difference between the attachment and the base attachment, replacing said attachment with said base attachment-related identifier and the difference, and; forwarding the message for transfer to the receiving entity, at the receiving entity responsive to the message with said substantially identifier and the difference being attached thereto: retrieving from a memory the base attachment on the basis of said base attachment-related identifier, creating the attachment by combining said difference with the base attachment reconstructing the original multipart message by replacing the identifier and the difference with the attachment to the message received, sending the reconstructed original multipart message to the recipient.