Returns the selected file attachment.
<readAttachmentRequest> <id type="uid"/> <offset type="int"/> <length type="int"/> </readAttachmentRequest>
<readAttachmentResponse> <status type="Status"/> </readAttachmentResponse>
Specifies the ID of the attachment to read.
Specifies the number of bytes to read from the offset.
Specifies the starting position for reading the attachment.
Returns the success or failure of the method.