feat(preview-server): error feedback for rate limiting

[gabrielmfern]

Before the response from fetch was, for some reason, throwing an error and falling back to the generic error message when there was a rate limiting. I'm not sure what causes it, but moving the fetch to a server action fixes this temporarily.

To illustrate, if the code is changed to

try {
  const response = await fetch('https://react.email/api/send/test', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      to,
      subject,
      html: markup,
    }),
  });

  if (response.ok) {
    toast.success('Email sent! Check your inbox.');
  } else if (response.status === 429) {
    toast.error('Too many requests. Try again in around 1 minute');
  } else {
    toast.error('Something went wrong. Please try again.');
  }
} catch (exception) {
  console.dir(exception);
  toast.error('Something went wrong. Please try again.');
}

The error message when trying to send more emails than the rate limiting window we have set up allows becomes:

And the exception in the console looks like:

TypeError: Failed to fetch
    at onFormSubmit (http://localhost:3000/_next/static/chunks/packages_preview-server_src_components_cfb89c94._.js?id=%255Bproject%255D%252Fpackages%252Fpreview-server%252Fsrc%252Fcomponents%252Fsend.tsx+%255Bapp-client%255D+%2528ecmascript%2529:31:36)
    at onSubmit (http://localhost:3000/_next/static/chunks/packages_preview-server_src_components_cfb89c94._.js?id=%255Bproject%255D%252Fpackages%252Fpreview-server%252Fsrc%252Fcomponents%252Fsend.tsx+%255Bapp-client%255D+%2528ecmascript%2529:97:45)
    at executeDispatch (http://localhost:3000/_next/static/chunks/47c98_next_dist_compiled_react-dom_5686b1df._.js:10308:13)
    at runWithFiberInDEV (http://localhost:3000/_next/static/chunks/47c98_next_dist_compiled_react-dom_5686b1df._.js:959:74)
    at processDispatchQueue (http://localhost:3000/_next/static/chunks/47c98_next_dist_compiled_react-dom_5686b1df._.js:10334:41)
    at http://localhost:3000/_next/static/chunks/47c98_next_dist_compiled_react-dom_5686b1df._.js:10609:13
    at batchedUpdates$1 (http://localhost:3000/_next/static/chunks/47c98_next_dist_compiled_react-dom_5686b1df._.js:2247:44)
    at dispatchEventForPluginEventSystem (http://localhost:3000/_next/static/chunks/47c98_next_dist_compiled_react-dom_5686b1df._.js:10410:9)
    at dispatchEvent (http://localhost:3000/_next/static/chunks/47c98_next_dist_compiled_react-dom_5686b1df._.js:12925:37)
    at dispatchDiscreteEvent (http://localhost:3000/_next/static/chunks/47c98_next_dist_compiled_react-dom_5686b1df._.js:12907:64)

[changeset-bot]

🦋 Changeset detected

Latest commit: 89d577f

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@react-email/preview-server	Patch
react-email	Patch

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Project	Deployment	Preview	Comments	Updated (UTC)
react-email	Ready	Preview	Comment	Dec 8, 2025 2:05pm
react-email-demo	Ready	Preview	Comment	Dec 8, 2025 2:05pm

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npm i https://pkg.pr.new/resend/react-email/@react-email/preview-server@1735

commit: 89d577f