Nodemailer 配置在开发模式下工作，在 VPS 上不起作用

问：

下面的 Nodemailer 代码在笔记本电脑上的开发模式下工作，但在 Ubuntu VPS 上部署时不起作用。我收到transporter.verify错误。

使用开发模式时，相同的代码也适用于另一个 VPS 以及我的笔记本电脑。 不知道为什么它不能在我的新VPS上运行。

节点方法

async function createPrimaryAccount(reqBody, origin, user) {

  // some code - which works - checked using console.log

  console.log('sending email next');
  // send email
  await sendVerificationEmail(account.email, account.verificationToken, account.clientName, origin);

}


async function sendVerificationEmail(email, verificationToken, clientName, origin) {
  console.log('acct service sendVerificationEmail email, clientName, origin', email, clientName, origin);

  let message;
  const verifyUrl = `${origin}/auth/verify-email?token=${verificationToken}`;
  message =
  `<h3 style="background-color: rgb(63, 81, 181); color: white; padding: 5px 10px">BFSI EDGE's CS Web App: Verification Email</h3>
  <p>This email was sent to you because your email address was used for registering a user on BFSI EDGE's CS Web Application for the client: ${clientName}.</p>
  <p>In case you have not done so, do not click on the below link.</p>
  
  <p>If this is a valid registration, please click the below link to verify your email address:</p>
  <p><a href="${verifyUrl}">CLICK HERE TO VERIFY</a></p>
  <p></p>
  <p>Note that this email cannot receive replies. For any clarification, contact your company's admin.
  </p>
  <p style="background-color: rgb(63, 81, 181); color: white; padding: 5px 10px">BFSI EDGE  Address</p>`;

  
  try {
    await sendEmail({
        to: email,
        subject: 'BFSI-EDGE CS Web-App: Registration Verification required',
        html: message
    }); 

    console.log('Verification email sent.')
    // Getting this log but its not correct as there is an error is sendEmail method

  } catch(err) {
    console.log('Error while sending verification email: ' + err)
  }

}


async function sendEmail({ to, subject, html, from = config.mailServerOptions.auth.user}) {
  console.log('helper sendEmail - from', from)
  const transporter = nodemailer.createTransport(config.mailServerOptions);
  let sendEmail = true;
  transporter.verify(function(error, success) {
    if (error) {
      sendEmail = false;
      console.log('helper sendEmail - transporter.verify error:', error);
      /// GETTING THE ABOVE ERROR

    } else {
      console.log('helper sendEmail - transporter.verify - OKAY')
      if(sendEmail) {
        console.log('helper sendEmail - sending email NOW')
        try {
          transporter.sendMail({ from, to, subject, html });
    
        } catch (err) {
          console.log('helper sendEmail - transporter.sendMail error:', err);
        }
      }
    }
  });
}

config.mailServerOptions - 我已经尝试了以下两个选项，nodemailer 所需的邮件服务器选项。

 "mailServerOptions": {
    "pool": true,
    "host": "smtp.example.com",
    "auth": {
      "user": "[email protected]",
      "pass": "password"
    },
    "tls": {
      "rejectUnauthorized": false
    }
  }


  "mailServerOptions": {
    "service": "gmail",
    "auth": {
      "user": "[email protected]",
      "pass": "password"        // USED Google App password here
    },
    "tls": {
      "rejectUnauthorized": false
    }
  }

console.log ：以下是上述代码中的控制台注销语句。

sending email next
acct service sendVerificationEmail email, clientName, origin [email protected] BFSI EDGE https://demo-cs.bfsiapp.com
helper sendEmail - from [email protected]
Verification email sent.
helper sendEmail - transporter.verify error: Error: Connection timeout
    at SMTPConnection._formatError (/root/demo-cs/node_modules/nodemailer/lib/smtp-connection/index.js:784:19)
    at SMTPConnection._onError (/root/demo-cs/node_modules/nodemailer/lib/smtp-connection/index.js:770:20)
    at Timeout.<anonymous> (/root/demo-cs/node_modules/nodemailer/lib/smtp-connection/index.js:229:22)
    at listOnTimeout (node:internal/timers:573:17)
    at process.processTimers (node:internal/timers:514:7) {
  code: 'ETIMEDOUT',
  command: 'CONN'
}