With Resend’s free tier, the default sender address is
onboarding@resend.dev. When using this address, Resend only allows delivery to the email address registered on your Resend account. If you want users to receive magic links at any email address, you need to verify a custom domain at resend.com/domains and set the RESEND_FROM_DOMAIN environment variable.1
Create a Free Resend Account
Go to resend.com and sign up for a free account. The free tier is sufficient for most self-hosted Lynkz deployments — it covers up to 3,000 emails per month and 100 per day.
2
Get Your API Key
After signing in, open the Resend dashboard and navigate to API Keys. Click Create API Key, give it a descriptive name (e.g.
lynkz-production), and copy the key that is displayed. You will only be shown this key once, so copy it before closing the dialog.3
Add the API Key to Vercel
In your Vercel project dashboard, go to Settings → Environment Variables and add the following variable:Replace
re_xxxxxxxxxxxx with your actual key. Make sure the variable is available to your Production environment (and optionally Preview). After adding it, redeploy your project for the change to take effect.4
(Optional) Verify a Custom Sender Domain
If you want to send magic links to any email address — not just your own Resend account email — verify a domain you own:Lynkz will then send magic link emails from
- Go to resend.com/domains and click Add Domain.
- Follow the DNS verification steps for your domain registrar.
- Once verified, add a second environment variable to your Vercel project:
noreply@yourdomain.com. If this variable is not set, it falls back to the default onboarding@resend.dev sender.