The <message> element is a child of the<mail> element. Its content is used to construct a message body for the SMTP message. At least one <message> element is required. Multiple <message> elements can be supplied when constructing an SMTP message with alternative representations of the message body (such as plain text and HTML, or English and another language).
mime-type: Optionally specifies the MIME type of the message body constructed by the <message> element (such as text/plain or text/html). If the mime-type attribute is not present, the driver attempts to automatically discover the MIME type.
E-mail clients can use the MIME type when an SMTP message has alternative representations in order to choose the best representation to display.
language: Optionally specifies the language of the message body constructed by the <message> element. The value should follow the SMTP specification. If the language attribute is not present, no default is supplied.
E-mail clients can use the language specification when an SMTP message has alternative representations in order to choose the best representation to display.