func (msg *message) addBody(contentType string, body []byte) {
body = []byte(msg.replaceCIDs(string(body)))
header := make(textproto.MIMEHeader)
header.Set("Content-Type", contentType+"; charset="+msg.charset)
header.Set("Content-Transfer-Encoding", msg.encoding.String())
msg.write(header, body, msg.encoding)
}
// openMultipart creates a new part of a multipart message
func (msg *message) openMultipart(multipartType string) {
// create a new multipart writer
msg.writers = append(msg.writers, multipart.NewWriter(msg.body))
// create the boundary
contentType := "multipart/" + multipartType + ";\n \tboundary=" + msg.writers[msg.parts].Boundary()
// if no existing parts, add header to main header group
if msg.parts == 0 {
msg.headers.Set("Content-Type", contentType)
} else { // add header to multipart section
header := make(textproto.MIMEHeader)
header.Set("Content-Type", contentType)
msg.writers[msg.parts-1].CreatePart(header)
}
msg.parts++
}