Recipe: Add a transactional email

1. Create the template in emails/your-email.tsx:

   import { Text } from "@react-email/components";
   import { EmailButton, EmailLayout } from "./components/layout";
    
   export function YourEmail({ someProp }: { someProp: string }) {
     return (
       <EmailLayout preview="Short inbox preview text" heading="Your heading">
         <Text style={{ fontSize: "14px", color: "#3f3f46", lineHeight: "22px" }}>
           Body copy. {someProp}
         </Text>
         <EmailButton href="https://example.com">Call to action</EmailButton>
       </EmailLayout>
     );
   }
    
   export default YourEmail;
    
   // Shown by `npm run email:dev`'s preview server.
   YourEmail.PreviewProps = { someProp: "example value" };

   Use EmailLayout/EmailButton from emails/components/layout.tsx for consistent branding — plain inline styles only, email clients don't run Tailwind.

2. Preview it: npm run email:dev, open the printed URL, find your file in the sidebar. Edits hot-reload.

3. Send it from server code:

   import { sendEmail } from "@/lib/email";
   import { YourEmail } from "@/emails/your-email";
    
   await sendEmail({
     to: user.email,
     subject: "Your subject line",
     react: YourEmail({ someProp: "value" }),
     // critical: true only if the user is blocked without this email
     // (verification, password reset) — otherwise leave it best-effort.
   });

4. Verify: without RESEND_API_KEY set, confirm you see [email] RESEND_API_KEY not set — skipping "Your subject line" to ... in the server log rather than an error. With a real key, check the Resend dashboard for delivery.

To remove an email, delete its file from emails/ and the sendEmail call site — there's no registry to update elsewhere.