---
title: 'Email (Resend)'
description: 'Transactional email via Resend with a dev-only file-preview fallback.'
canonical: 'https://cartwright.app/docs/features/email-resend'
---

# Email (Resend) (/docs/features/email-resend)



Cartwright sends transactional email through Resend. The mailer lives in `lib/mailer/` (the directory) with `lib/mailer/resend.ts` as the Resend-specific adapter. Templates render HTML server-side using palette values mirrored into `brand.config.ts:emailColors` (Stripe Elements + email clients both need hardcoded palette since they cannot read your CSS variables).

<Cards>
  <Card title="Full setup walkthrough — Resend + your domain" href="/docs/email/resend-sending" />
</Cards>

## Templates shipped [#templates-shipped]

* **Order confirmation** — sent on successful Stripe webhook.
* **Magic link** — sent by NextAuth on sign-in.

Additional templates (order shipped, refund processed, etc.) are scaffolded but require per-fork wiring. Check `lib/mailer/templates/` for the current shipped set.

<Callout type="info">
  The exact template inventory and naming may differ slightly between cartwright versions. Always read `ls lib/mailer/` in your fork to confirm what is actually present before promising a customer template behaviour.
</Callout>

## Marketing automations (opt-in) [#marketing-automations-opt-in]

Resend isn't only the transactional transport — an opt-in `marketingAutomations` flag turns it into the shop's **lifecycle email engine** too. When on (and a Resend key is set), Cartwright **emits three events** to [Resend Automations](https://resend.com/features/automations):

* `cartwright.user.created` — welcome series
* `cartwright.cart.abandoned` — recovery drip (the abandoned-cart cron emits the event instead of sending a single mail; no double-send)
* `cartwright.order.placed` — post-purchase series

Resend runs the actual sequences you wire in its dashboard against those event names — Cartwright **emits events only**, so it stays the source of truth without becoming a marketing-automation platform itself. Events are **consent-gated** (confirmed newsletter subscribers), and the whole policy lives in one helper so you can broaden it. Default-off; inert without a Resend key. See `docs/marketing-automations.md` in your fork.

## Dev fallback [#dev-fallback]

Without `RESEND_API_KEY`, the mailer writes every outbound email to `.mail-previews/` as an HTML file. The path is `.mail-previews/<timestamp>-<template>.html`. Open in a browser to inspect rendering or grab a magic link without leaving local dev.

The fallback is silent — no warning printed unless you opt in. Production deploys should always have a real key + verified domain to avoid receipts going nowhere.

## Resend domain setup [#resend-domain-setup]

To send from a custom domain (e.g. `noreply@my-shop.com`):

<Steps>
  1. In the Resend dashboard, add your domain.
  2. Add the SPF and DKIM records Resend gives you to your DNS provider.
  3. Wait for DNS propagation (usually under 30 minutes).
  4. Verify the domain in Resend. Send a test email through the dashboard.
  5. Set `RESEND_API_KEY` in Vercel (Production scope).
  6. Update `brand.config.ts:emails.from` and `emails.fromName` to match the verified sender.
</Steps>

If `emails.from` does not match a verified Resend sender, Resend rejects the send with a clear API error. The shop's order flow still completes — the order is created, payment is captured — but the customer does not receive a receipt. Watch Sentry (if configured) for these errors during the first day of production traffic.

## From-address coordination [#from-address-coordination]

Two places need to agree on the from-address:

1. `brand.config.ts:emails.from` — what cartwright reads when calling the mailer.
2. Resend's verified senders — what Resend allows.

They drift apart easily during forks. The setup wizard in `/admin/setup` is the place to align them; for env-only operators, set `RESEND_FROM_EMAIL` if your fork supports it.

<Cards>
  <Card title="Recipe: Sentry + Resend setup" href="/docs/recipes/sentry-resend-setup" />

  <Card title="Auth (magic link)" href="/docs/features/auth-magiclink" />
</Cards>