Gmail 421 4.7.26: “rate limited because it is unauthenticated”
What the bounce means and the exact steps to stop it.
The bounce looks like this
421-4.7.26 This email has been rate limited because it is unauthenticated.
421-4.7.26 Unauthenticated email from yourdomain.com is not accepted due to domain's DMARC policy, but temporary DNS failures …
What it means
The temporary version of 5.7.26: Gmail is slowing down and deferring your mail because it is not authenticated with SPF or DKIM. Your server will retry, but if nothing changes the messages bounce for good after a few days. The second variant means Gmail could not even read your DNS records – check that your DNS host answers reliably.
How to fix it
- Check the domain below; fix every red SPF or DKIM line first.
- Add the sending service to SPF (SPF generator) and enable DKIM with your own domain.
- Publish a DMARC record (DMARC generator) – start with
p=none. - If the error mentions DNS failures, test that your nameservers respond (the checker shows “unknown” when DNS does not answer).
Check your domain now
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