Send email with Resend

This guide explains how to send the emails of Casdoor through Resend. Resend is an API-based service, so you need only an API key, not an SMTP host or credentials.

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Learning outcomes

• Create a Resend API key and verify a domain.
• Add Resend as an email provider in Casdoor and test it.

What you need

• A Resend account
• Administrator access to the Casdoor admin console

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Prepare Resend

1. In the Resend dashboard, click Create API Key and give it Sending access, or full access if you also use webhooks.
2. Go to Domains, add your sending domain, and complete the DNS verification. For tests, you can use the shared domain of Resend, onboarding@resend.dev. In production, use a verified domain of your own.

Add the provider in Casdoor

1. In the Casdoor admin console, go to Identity > Providers and add a provider.

2. Set Category to Email and Type to Resend.

3. Fill in the fields:

   Field	Description
   Secret Key	Your Resend API key
   From Address	Verified sender address (e.g. no-reply@yourdomain.com)
   From Name	(Optional) Sender display name
   Email Title	Email subject template
   Email Content	Email body (HTML supported)

   Leave Host, Port, and Username empty. Resend doesn't use them.

4. Save the provider.

Verify the result

Click Send Testing Email and check that the message arrives, before you add the provider to an application.

See also

• Email providers