Nodemailer works locally. Then production happens.

// routes/email.ts
import { Ark } from "ark-email";
import { Router } from "express";

// No createTransport(), no pool config, no close() to forget
const ark = new Ark();
const router = Router();

router.post("/signup", async (req, res) => {
  try {
    const { id } = await ark.emails.send({
      from: "[email protected]",
      to: req.body.email,
      subject: "Welcome to YourApp!",
      html: "<h1>You're in!</h1>",
    });
    res.json({ emailId: id });
  } catch (err) {
    // Actual error—not silent failure
    console.error("Email failed:", err.message);
    res.status(500).json({ error: "Email failed" });
  }
});

export default router;

// app/api/welcome/route.ts
// Works on Vercel Edge—Nodemailer doesn't (requires net, tls modules)
import { Ark } from "ark-email";

export const runtime = "edge";  // Edge runtime—no Node.js modules

const ark = new Ark();

export async function POST(request: Request) {
  const { email, name } = await request.json();

  await ark.emails.send({
    from: "[email protected]",
    to: email,
    subject: `Welcome, ${name}!`,
    html: `<h1>Hi ${name}!</h1><p>Thanks for signing up.</p>`,
  });

  return Response.json({ sent: true });
}

// src/index.ts
// Nodemailer can't run here—no net/tls. Ark uses fetch.
import { Ark } from "ark-email";

export default {
  async fetch(request: Request, env: Env): Promise<Response> {
    const ark = new Ark({ apiKey: env.ARK_API_KEY });

    const { email } = await request.json();

    await ark.emails.send({
      from: "[email protected]",
      to: email,
      subject: "Your alert triggered",
      html: "<p>Something happened. Check it out.</p>",
    });

    return new Response(JSON.stringify({ sent: true }));
  },
};