The video for this guide is coming soon. The written steps below cover everything.

What you get

Every email the template sends (sign-in codes, receipts, booking confirmations, replies, campaigns) goes out from your own domain. You see delivered, opened, clicked, bounced, and spam complaints for each one in Admin → Outbox and on each customer's page.

Until this is connected, emails only appear in the Outbox, and customers can't sign in.

Steps

Create a Resend account and add your domain under Domains. Add the DNS records it shows at your domain registrar and wait for Verified.
Create an API key with sending access and set it as RESEND_API_KEY.
Set EMAIL_FROM to a sender on that domain, like "Acme <hello@acme.com>", and OWNER_EMAIL to your own address.
Under your domain's Configuration, turn on open tracking and click tracking.
Add a webhook to https://YOUR_URL/api/webhooks/resend with every email.* event, and set its signing secret as RESEND_WEBHOOK_SECRET.

Check it works

Sign out and sign back in: the code should arrive in a few seconds. Then open Admin → Outbox and watch it change to delivered and opened.

What the video covers

Verifying a domain (and what the DNS records do)
Where each key and secret goes
Reading delivery and open status in the Outbox

Some links are affiliate links: signing up through them may earn us a commission at no extra cost to you.