Nodemailer in Javascript with SMTP connection to Email Pro Email - Not Working

Hello there,

I am currently attempting to use Nodemailer in my Express.js server to send emails but it doesn't seem to work for me. I have used the verify function from Nodemailer to check if the connection via SMTP was successful and this is returned from the request:
```
{
"code": "EAUTH",
"response": "535 5.7.1 Authentication failed",
"responseCode": 535,
"command": "AUTH PLAIN"
}
```

Here is the code in Javascript I am using to send an email with Nodemailer with my custom domain:
```js
app.get('/mail/verify', (req, res) => {
var transporter = nodemailer.createTransport({
host: process.env.MAIL_HOST,
port: process.env.MAIL_PORT,
secure: process.env.MAIL_SECURE,
auth: {
user: process.env.MAIL_USER,
pass: process.env.MAIL_PASS
},
tls: {
rejectUnauthorized: false
},
});

transporter.verify((err, success) => {
if (err) {
res.send(err);
} else {
res.send('Server is ready to take our messages!');
}
});
});
```
These are the .env variables I am using:
```.env
MAIL_HOST = 'ssl0.ovh.net'
MAIL_PORT = 465
MAIL_SECURE = true
MAIL_USER = 'example@email.com'
MAIL_PASS = 'password'
```
If I replace 'ssl0.ovh.net' with the server of my Email Pro, I get a ETIMEOUT error. Does anyone know what may be causing this and what I can do to make this work?

Thank you for taking the time to read this and I look forward to any responses!