Patent ID: 8260861

Claim:
A non-transitory computer readable storage medium storing a set of instructions executable by a processor, the set of instructions being operable to: receive an electronic mail including an attachment file; separate the attachment file from the electronic mail when a file size of the attachment file is greater than a predefined size threshold; determine whether a remote file server has previously received a copy of the attachment file; send the attachment file to the remote file server, if the remote file server has not previously received a copy of the attachment file, the remote file server being adapted to build a substitute file upon receiving the attachment file, the substitute file including a hash value computed from the attachment file, wherein, when the attachment file does not include prohibited content, the substitute file includes identifying data for retrieving one of the attachment file and the copy of the attachment file from the remote file server and wherein, when the attachment file includes prohibited content, the substitute file does not provide access to the attachment file and includes an indication of the prohibited content; receive the substitute file from the remote file server; replace the attachment file with the substitute file; forward the electronic mail with the substitute file to the receiver; receive a request from the receiver to obtain the attachment file, the request including the identifying data and the hash file; and send the attachment file to the receiver in response to the request.