我已经使用此成功发送了简单的电子邮件：

SimpleMailMessage mailMessage = new SimpleMailMessage();

mailMessage.setTo("someone@abc.com");
mailMessage.setSubject("This is the test message for testing gmail smtp server using spring mail");
mailMessage.setFrom("abc@gmail.com");
mailMessage.setText("This is the test message for testing gmail smtp server using spring mail. \n" +
        "Thanks \n Regards \n Saurabh ");
mailSender.send(mailMessage);

我需要更改什么设置才能发送HTML电子邮件