nodemailer

index.js

require('dotenv').load();

const express       = require('express');
const bodyParser    = require('body-parser');
const cors          = require('cors');
const nodemailer    = require('nodemailer');
const hbs           = require('nodemailer-express-handlebars');
const app           = express();

const port          = process.env.PORT || 4000;
const uri           = process.env.SMTP;

const transporter   = nodemailer.createTransport(uri);

transporter.use('compile', hbs({
    viewPath: "views",
    extName: ".hbs"
}))

const mailOptions = {
    from: 'BUUUU 👻 <tosi.paulo@gmail.com>',
    to: 'tosi.paulo@gmail.com', 
    subject: 'BUUUU 👻', 
    template: 'main'
}

app.use(bodyParser.urlencoded({ extended: false }))
app.use(cors());

app.get('/', (req, res) => {
    res.status(200).json({msg: 'ok'})
})

app.post('/email', (req, res) => {
    const { nome, telefone, email } = req.body
    const mensagem = { ...mailOptions,  ...{context: {nome, telefone, email}}}
    transporter.sendMail(mensagem, (error, info) => {
        if (error) {
            return console.log(error);
        }
        console.log('Message sent: ' + info.response);
    })
    res.status(200).json({ mensagem: "E-mail enviado com sucesso" })
})

app.listen(port, () => {
    console.log('running ' + port)
})

main.hbs

Olá {{nome}} telefone {{telefone}} e email {{email}}

package.json

{
  "name": "nodemailer",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "dependencies": {
    "body-parser": "^1.18.3",
    "cors": "^2.8.4",
    "dotenv": "^6.0.0",
    "express": "^4.16.3",
    "nodemailer": "^4.6.8",
    "nodemailer-express-handlebars": "^3.0.0"
  },
  "devDependencies": {},
  "scripts": {
    "start": "node index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "Paulo Tosi <tosi.paulo@gmail.com> (http://www.paulotosi.com.br/)",
  "license": "MIT"
}

Procfile

web: node index.js