Enviar emails con Node.js

npm install @emailit/node

EMAILIT_API_KEY=secret_••••••••••••••••••••••••••••••••

import { Emailit } from '@emailit/node';

const emailit = new Emailit(process.env.EMAILIT_API_KEY);

const email = await emailit.emails.send({
  from: 'Acme <hello@acme.com>',
  to: 'ada@example.com',
  subject: 'Welcome to Acme',
  html: '<p>Thanks for signing up.</p>',
  text: 'Thanks for signing up.',
});

console.log(email.id); // em_…

import express from 'express';
import { Emailit } from '@emailit/node';

const app = express();
const emailit = new Emailit(process.env.EMAILIT_API_KEY);

app.post('/signup', express.json(), async (req, res) => {
  const { email } = req.body;
  // Create the user here, then send the welcome email.
  const sent = await emailit.emails.send({
    from: 'Acme <hello@acme.com>',
    to: email,
    template: 'welcome',
    variables: { email },
  });
  res.status(201).json({ emailId: sent.id });
});

app.listen(3000);

import {
  AuthenticationException,
  RateLimitException,
  UnprocessableEntityException,
  ApiErrorException,
} from '@emailit/node';

try {
  await emailit.emails.send(message);
} catch (err) {
  if (err instanceof RateLimitException) {
    // 429: wait err.jsonBody.retry_after seconds, then retry
  } else if (err instanceof AuthenticationException) {
    // 401: the API key is missing or invalid
  } else if (err instanceof UnprocessableEntityException) {
    // 422: for example, the from domain isn't verified
  } else if (err instanceof ApiErrorException) {
    console.error(err.httpStatus, err.jsonBody);
  } else {
    throw err;
  }
}

import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
  host: 'smtp.emailit.com',
  port: 587,
  secure: false, // upgraded with STARTTLS after connecting
  requireTLS: true,
  auth: {
    user: 'emailit',
    pass: process.env.EMAILIT_API_KEY,
  },
});

const info = await transporter.sendMail({
  from: 'Acme <hello@acme.com>',
  to: 'ada@example.com',
  subject: 'Welcome to Acme',
  text: 'Thanks for signing up.',
  html: '<p>Thanks for signing up.</p>',
});

console.log(info.response); // 250 2.0.0 OK: queued as em_…

import express from 'express';
import { createHmac, timingSafeEqual } from 'node:crypto';

function verifyEmailitSignature(rawBody, signature, timestamp, secret) {
  if (!signature || !timestamp) return false;
  const age = Math.abs(Math.floor(Date.now() / 1000) - Number(timestamp));
  if (!Number.isFinite(age) || age > 300) return false; // reject replays older than 5 minutes
  const expected = createHmac('sha256', secret).update(`${timestamp}.${rawBody}`).digest('hex');
  const a = Buffer.from(expected);
  const b = Buffer.from(signature);
  return a.length === b.length && timingSafeEqual(a, b);
}

export const webhooks = express.Router();

webhooks.post('/webhooks/emailit', express.raw({ type: 'application/json' }), (req, res) => {
  const rawBody = req.body.toString('utf8');
  const valid = verifyEmailitSignature(
    rawBody,
    req.get('x-emailit-signature'),
    req.get('x-emailit-timestamp'),
    process.env.EMAILIT_WEBHOOK_SECRET,
  );
  if (!valid) return res.status(401).send('Invalid signature');

  // The body is an array of up to 100 events.
  const events = JSON.parse(rawBody);
  for (const event of events) {
    switch (event.type) {
      case 'email.delivered':
        // event.data.object.id is the em_ ID
        break;
      case 'email.bounced':
      case 'email.complained':
        // stop emailing event.data.object.to
        break;
    }
  }

  res.sendStatus(200);
});