无法与nodemailer一起使用localhost smtp（Mercury Mail软件）

Question

我想用localhost smtp（Mercury Mail）配置在localhost上运行的express项目。 我已经配置了以下代码：

var express = require('express');
var router = express.Router();

var nodemailer = require('nodemailer');

/* GET users listing. */
router.get('/', function(req, res, next) {
  res.render('contact', { title : 'Contact us'});
});

router.post('/send', function(req, res) {
   // create reusable transporter object using the default SMTP transport
    var transporter = nodemailer.createTransport("SMTP", {
        host: 'localhost',
        port: 25,
        secure: false, // true for 465, false for other ports
        auth: {
            user: 'piyush@localhost', // generated ethereal user
            pass: '123456' // generated ethereal password
        }
    });

    // setup email data with unicode symbols
    var mailOptions = {
        from: 'piyush', // sender address
        to: 'piyush@localhost', // list of receivers
        subject: 'Hello', // Subject line
        text: 'Hello world?', // plain text body
        //html: '<b>Hello world?</b>' // html body
    };

    // send mail with defined transport object
    transporter.sendMail(mailOptions, (error, info) => {
        if (error) {
            return console.log(error);
        }
        console.log('Message sent: %s', info.messageId);
        // Preview only available when sending through an Ethereal account
        console.log('Preview URL: %s', nodemailer.getTestMessageUrl(info));

        // Message sent: <b658f8ca-6296-ccf4-8306-87d57a0b4321@example.com>
        // Preview URL: https://ethereal.email/message/WaQKMgKddxQDoou...
    });

});

module.exports = router;

，但在正确配置后仍然无法正常工作。我对此进行了过多搜索，但每个示例都使用SMTP提供程序（例如Gmail，Hotmail等）。