# Receipt email

Production checkout stays closed until the Resend free plan is configured. After confirmation, ShipW3 queues one receipt per order. The queue retries with the same Resend idempotency key, so a retry does not send a second email. The pay page also shows the download link.

Verify a sending subdomain in Resend, then set `MAIL_FROM` and `RESEND_API_KEY`. Stay on the free plan: 100 emails a day and 3,000 a month. The receipt includes the product, order reference, explorer link, seven-day download link, and support address.