code: public void throwMailTemplateFromClasspathNotFoundException(Postcard postcard, String path, String realPath) {
          final ExceptionMessageBuilder br = new ExceptionMessageBuilder();
          br.addNotice("Not found the mail template file from classpath");
          br.addItem("Advice");
          br.addElement("Confirm the location and file path of mail template.");
          br.addElement("And the file should be in valid classpath.");
          br.addElement("");
          br.addElement("While, The searching mail template process needs");
          br.addElement("context class-loader of current thread.");
          br.addElement("If the class-loader is null, MailFlute cannot search it.");
          br.addItem("Postcard");
          br.addElement(postcard);
          br.addItem("Mail Template");
          br.addElement("plain path : " + path);
          br.addElement("real path  : " + realPath);
          br.addItem("Context ClassLoader");
          br.addElement(Thread.currentThread().getContextClassLoader());
          final String msg = br.buildExceptionMessage();
          throw new SMailTemplateNotFoundException(msg);
      }
docs: =============