Order confirmation emails: what to include and how to send them

async function onPaymentSucceeded(order) {
  const res = await fetch("https://api.sendpository.com/v1/emails", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${process.env.SENDPOSITORY_API_KEY}`,
      "Content-Type": "application/json",
      // Duplicate payment events can't send two receipts.
      "Idempotency-Key": `order-${order.id}-confirmation`,
    },
    body: JSON.stringify({
      from: "Acme Store <orders@mail.yourdomain.com>",
      to: [order.email],
      reply_to: ["support@yourdomain.com"],
      subject: `Order #${order.number} confirmed`,
      html: renderOrderEmail(order),
      text: `Order #${order.number} - total ${order.total}`,
      tags: { type: "order_confirmation", order_id: String(order.id) },
    }),
  });
  if (!res.ok) throw new Error((await res.json()).error.type); // let the job retry
}