email.js

'use strict';

// npm i smtp-client
const {SMTPClient} = require('smtp-client');

let message = 'From: "Girl Hà Đông" <hi@ngxson.com>\r\n'
  + 'To: "Boy Hà Nội" <xaeyyctwoeoa@dropmail.me>\r\n'
  + 'Date: Sat, 14 Mar 2020 16:00:00 0000\r\n'
  + 'Subject: Đây là cái tiêu đề email\r\n'
  + '\r\n'
  + 'Xin chào boy HN. Đây là nội dung email tôi muốn gửi cho bạn.\r\n';
 
let s = new SMTPClient({
  host: 'mx.dropmail.me',
  port: 25
});

let log = console.log;
 
(async function() {
  log(await s.connect());
  log(await s.greet({hostname: 'ngxson.com'})); // runs HELO command
  log(await s.mail({from: 'hi@ngxson.com'})); // runs MAIL FROM command
  log(await s.rcpt({to: 'xaeyyctwoeoa@dropmail.me'})); // runs RCPT TO command
  log(await s.data(message)); // runs DATA command and streams email source
  log(await s.quit()); // runs QUIT command
})().catch(console.error);