The <attachment> element is a child of the <mail> element. It can have the same content as <message>, or it can have a filename as content. Zero or more <attachment> elements can appear as children of the <mail> element.
mime-type: Optionally specifies the MIME type of the attachment. If the mime-type attribute is not present, the driver attempts to automatically discover the MIME type.
language: Optionally specifies the language of the attachment. If the language attribute is not present, no default is supplied.