如何从JSP发送电子邮件？我有一个错误

<%@ page import="javax.mail.*" %>
<%@ page import="javax.mail.internet.*" %>
<%@ page import="java.util.Properties" %>

<%
    // 邮件发送者的邮箱地址和密码
    String senderEmail = "your_email@example.com";
    String senderPassword = "your_password";

    // 邮件接收者的邮箱地址
    String recipientEmail = "recipient_email@example.com";

    // 邮件主题和内容
    String emailSubject = "Hello from JSP";
    String emailContent = "This is a test email sent from JSP.";

    // 邮件服务器的主机名和端口号
    String mailServerHost = "smtp.example.com";
    String mailServerPort = "587";

    // 创建Properties对象，设置邮件服务器的配置信息
    Properties props = new Properties();
    props.put("mail.smtp.host", mailServerHost);
    props.put("mail.smtp.port", mailServerPort);
    props.put("mail.smtp.auth", "true");
    props.put("mail.smtp.starttls.enable", "true");

    // 创建Session对象，用于与邮件服务器进行通信
    Session session = Session.getInstance(props, new javax.mail.Authenticator() {
        protected PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication(senderEmail, senderPassword);
        }
    });

    try {
        // 创建MimeMessage对象，并设置邮件的各种属性
        MimeMessage message = new MimeMessage(session);
        message.setFrom(new InternetAddress(senderEmail));
        message.addRecipient(Message.RecipientType.TO, new InternetAddress(recipientEmail));
        message.setSubject(emailSubject);
        message.setText(emailContent);

        // 发送邮件
        Transport.send(message);

        out.println("Email sent successfully.");
    } catch (MessagingException e) {
        out.println("Failed to send email. Error message: " + e.getMessage());
    }
%>