Nodemailer /send gives 404 error - node.js

Question

I'm trying to use nodemailer to send a message from a standard website form to an email address. I have followed this tutorial and everything works on the local server. But when I upload the documentation to my hosting provider I get the following error:
POST http://mydomain.rs/send 404 (Not Found)
Not Found
The requested URL /send was not found on this server.
Additionally, a 404 Not Found error was encountered while trying to use an
ErrorDocument to handle the request.
I have three files relevant to the nodemailer, those are:
app.js
var http = require('http');
var express = require('express');
var nodemailer = require("nodemailer");
var bodyParser = require('body-parser');
var path = require('path');
var app = express();
var port = Number(process.env.PORT || 5000);
app.use(bodyParser.json()); // to support JSON-encoded bodies
app.use(bodyParser.urlencoded({
extended: true
}));
app.use(express.static(__dirname + '/'));
// Home page
app.get('/', function (req, res) {
res.sendFile('index.html');
//console.log
console.log('NodeMailer reading console log...' + req.url);
});
// sending mail function
app.post('/send', function (req, res) {
if (req.body.email == "" || req.body.subject == "") {
res.send("Error: Email & Subject should not blank");
return false;
}
// Sending Emails with SMTP, Configuring SMTP settings
var smtpTransport = nodemailer.createTransport("SMTP", {
host: "mail.mydomain.rs", // hostname
secureConnection: true, // use SSL
port: 465, // port for secure SMTP
auth: {
user: 'messages#mydomain.rs',
pass: 'password'
},
proxy: 'http://mydomain.rs:' + port
});
var mailOptions = {
from: "Node Emailer ✔ <messages#mydomain.rs>", // sender address
to: req.body.emailto, // list of receivers
subject: req.body.subject + " ✔", // Subject line
//text: "Hello world ✔", // plaintext body
html: "<b>" + req.body.description + "</b>" // html body
}
smtpTransport.sendMail(mailOptions, function (error, response) {
if (error) {
res.send("Email could not sent due to error: " + error);
} else {
res.send("Email has been sent successfully");
}
});
});
// Starting server
var server = http.createServer(app).listen(port, function () {
console.log("Server is Running on 127.0.0.1:" + port);
});
the part of the index page relevant to the form:
index.html
<form role="form" id="emailForm" method="post">
<div class="form_content">
<h2>KONTAKTIRAJTE NAS</h2>
<p id="msg"></p>
<input type="text" name="ime" placeholder="IME" required="required" />
<input type="tel" name="telefon" placeholder="TELEFON" />
<p class="mini_text">
Otvoreni od 8h - 17h
<br> Zatvoreni vikendom osim za posebne usluge
</p>
<input type="email" name="emailto" value="myactualemail#gmail.com" style="visibility: hidden; position: absolute;">
<input type="email" name="email" placeholder="EMAIL" required="required" />
<textarea name="description" placeholder="PORUKA" required="required"></textarea>
<button id="send" type="button">POŠALJI</button>
</div>
</form>
and the package.json
{
"name": "speednodemailers",
"version": "0.0.1",
"description": "NodeJs email form to send email using nodejs",
"dependencies": {
"body-parser": "^1.13.3",
"express": "^3.21.2",
"node-mailer": "^0.1.1",
"nodemailer": "^0.7.1"
}
}
So as I mentioned everything works perfectly on localhost, the problem occurs when I upload the project to my hosting provider.
Is there a step to the upload that I am missing?
Or a setting that I overlooked?
Any kind of help will be greatly appreciated as I am somewhat of a beginner at back-end stuff.
Thanks!