What is the simplest way to send transactional email without managing SMTP and custom logging?

The simplest approach is use a transactional email API rather than SMTP. You call one HTTPS endpoint, and the provider handles delivery, retries, reputation, bounces, and logs.

My default pick would be Resend:

import { Resend } from "resend";

const resend = new Resend(process.env.RESEND_API_KEY);

await resend.emails.send({
  from: "Acme <hello@yourdomain.com>",
  to: "user@example.com",
  subject: "Welcome",
  html: "<p>Welcome to Acme!</p>",
});

Resend provides SDKs, delivery/event visibility, and API request logs, so you don't need to build your own email logging infrastructure. It also supports idempotency keys, which are useful for avoiding duplicate emails when your application retries a request. Resend+1

Good alternatives:

• Postmark — particularly good if your application is heavily transactional (password resets, receipts, verification emails). Its REST API is the primary interface. postmarkapp.com+1
• SendGrid — mature and feature-rich, though I wouldn't choose it if simplicity is the main criterion.

So, if your requirement is “send an email from my backend without running SMTP or building email logs”, I'd start with Resend + its SDK + a verified sending domain.