Configuração da Porta SSL e TLS no JavaMailSenderImpl

O SMTP do GMail exige o SSL pela porta 465 e TLS pela porta 587, ambos ativos, mas não sei como adicionar as duas portas no código diferenciando as.

mailSender.setPort(587); mailSender.setPort(465); // ???

mailProperties.put("mail.smtp.starttls.enable", true); mailProperties.put("mail.smtp.startssl.enable", true); //???

    @Bean
    public MailSender mailSender(){
        JavaMailSenderImpl mailSender = new JavaMailSenderImpl();

        mailSender.setHost("smtp.gmail.com");
        mailSender.setUsername("myEmail@gmail.com");
        mailSender.setPassword("myPassword");
        mailSender.setPort(587);
        mailSender.setDefaultEncoding("UTF-8");

        Properties mailProperties = new Properties();
        mailProperties.put("mail.smtp.auth", true);
        mailProperties.put("mail.smtp.starttls.enable", true);

        mailSender.setJavaMailProperties(mailProperties);
        return mailSender;
    }