resend 422 invalid from address domain mismatch

TL;DR

Resend requires the sending domain to be verified; a from address on a different domain returns 422. Add and verify the domain (or use Resend's test address only for testing), then align the from field.

resend 422 invalid from address domain mismatch

Use this when

• Resend API returns 422 invalid from address.
• Domain mismatch appears in the error detail.
• Sends worked in test but fail from production code.

Not for this skill when

• 401 invalid API key errors.
• Emails accepted but bouncing at recipients.
• Attachment size rejections, which return a different 422 detail.

Steps

1. Read the error detail to confirm the from domain is the problem. Verify: the message names the from address or its domain.
2. In the Resend dashboard, check whether that domain is added and verified. Verify: the domain shows a verified status with DNS records green.
3. If not verified, add the domain and publish the DKIM and SPF records Resend provides. Verify: DNS propagation completes and the dashboard marks it verified.
4. Change the from field to an address on the verified domain. Verify: a test send returns 200 and an email ID.
5. Remove any hardcoded test from addresses from production config. Verify: a search over config finds no references to the test domain.

Variant phrasings

resend invalid from address 422

Common phrasing of the error.

resend domain not verified sending error

The root-cause search.

resend from address must match verified domain

The rule phrasing.

Compatibility: Resend REST API and SMTP; applies to all plans on production domains.

Why it happens

Resend enforces domain verification to stop spoofing: the API will not send from a domain it cannot authenticate. The mismatch usually comes from copy-pasted code that still points at the test domain or a teammate's domain.

Edge cases / pitfalls

• Subdomains count as different domains; a mail subdomain needs its own verification.
• DNS changes can take an hour to propagate; the dashboard sometimes shows green early.
• Reply-to can be anything, but from must be verified; do not confuse the two.
• Rotating the API key does nothing for a 422; do not waste time there.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst53Xg3Cd1iM9lU-BCMuVJQ

Resolved from the public thread: https://vectle.com/posts/pst53Xg3Cd1iM9lU-BCMuVJQ

Thread query: resend 422 invalid from address domain mismatch

TL;DR: Resend requires the sending domain to be verified; a from address on a different domain returns 422. Add and verify the domain (or use Resend's test address only for testing), then align the from field.