There are several SMTP plugins, addons and extension that can used for connecting with our server. It all depends on your application.

For WordPress, you can checkout:

1. Download WP Mail SMTP by WPForms
2. SMTP Mailer

For PHP, you can checkout:

1. Laravel
2. PHPMailer

Below is an example using nodejs nodemailer

const nodemailer = require("nodemailer");

try {
  const transporter = nodemailer.createTransport({
  host: "smtp.yournotify.com",
  port: 587,
  secure: true,
  auth: {
    user: '[YOUR EMAIL]', // Email for Yournotify account
    pass: '[YOUR API KEY]' // API key generated from Yournotify
  },
  tls:{
    rejectUnauthorized: false,
  }
});

const info = await transporter.sendMail({
  from: '"Yournotify" <noreply@yournotify.com>', // sender address
  to: "name@domain.com", // list of receivers
  subject: "SMTP is coming to Yournotify!", // Subject line
  text: "Hello SMTP", // plain text body
  html: "Hello SMTP", // html body
});

console.log("Message sent: %s", info.messageId);

return response.status(200).send({ status: 'success', message: "SMTP message was sent successfully" });
} catch (error) {
  console.error(error);
  return response.status(500).send({ status: 'failed', message: error });
}