The binary data that forms the attachment itself is separate from the SOAP message body so it is not parsed as part of a message, eliminating an expensive processing overhead.
The WSS specification provides a means to protect a message by encrypting and/or digitally signing a body, a header, an attachment, or any combination (or parts) of these.
WSS 规范提供通过对主体、标题、附件或其任意组合(或部分)进行加密和/或数字签名保护消息的方法。
3
One issue, though, is how to structure the E-mail: Do you send the XML transaction in the body of the mail or in an attachment?