Domains
How to avoid conflicts with your MX records
Learn how to avoid conflicts with your existing MX records when setting up a Resend domain.
What if my domain is not verifying?
Learn what steps to take when your domain doesn't seem to be verifying.
403 Error with Error Code 1010
Learn how to resolve a 403 error caused by a missing User-Agent header when sending requests to the Resend API.
403 Error Using Verified Domain
Learn how to resolve a 403 error caused by using a domain in your API request that doesn't match your verified domain.
403 Error Using resend.dev Domain
Learn how to resolve a 403 error when using the resend.dev domain to send emails to recipients other than your own.
Domain Already Registered by Another Account
Resolve the 403 domain already registered error by verifying domain ownership or starting a self-serve claim.
DMARC Analyzer
Analyze DMARC XML reports with a free, open-source tool built by Resend.