如何使用mails和nodejs跟踪点击、打开邮件？

const nodemailer = require('nodemailer');

// 创建一个SMTP传输对象
const transporter = nodemailer.createTransport({
  host: 'smtp.example.com',
  port: 587,
  secure: false,
  auth: {
    user: 'your-email@example.com',
    pass: 'your-password'
  }
});

// 邮件内容中插入跟踪链接
const mailOptions = {
  from: 'your-email@example.com',
  to: 'recipient@example.com',
  subject: 'Tracking Email',
  html: '<p>Click <a href="https://example.com/track?id=123">here</a> to track this email.</p>'
};

// 发送邮件
transporter.sendMail(mailOptions, (error, info) => {
  if (error) {
    console.log('Error:', error);
  } else {
    console.log('Email sent:', info.response);
  }
});

// 在服务器端接收跟踪链接的请求并记录数据
const express = require('express');
const app = express();

app.get('/track', (req, res) => {
  const emailId = req.query.id;
  const userId = req.query.user;
  const timestamp = new Date();

  // 将数据记录到数据库中
  // ...

  res.send('Tracking link clicked');
});

app.listen(3000, () => {
  console.log('Server started on port 3000');
});