MailFixIt

Gmail temporary SPF policy error

Gmail 451 4.7.24: The SPF record of the sending domain has one or more suspicious entries

Gmail temporarily rate limited mail because it considers one or more SPF entries suspicious. Check the exact MAIL FROM domain before changing DNS.

Problem description

Gmail reports:

451 4.7.24 The SPF record of the sending domain has one or more suspicious entries.

Run this automated test on my domain

Enter your domain. MailFixIt checks the relevant DNS records automatically and shows the evidence.
What MailFixIt can test: record selection, syntax, reachable dependencies, loops, void lookups, and an explicit sender path. It cannot reproduce Gmail's private policy or rate-limit decision.
Is this temporary or permanent?

451 is temporary. Keep normal retries with backoff while reviewing the policy.

Review safely

Resolution sequence

  1. Inventory every legitimate sender.
  2. Inspect the exact MAIL FROM domain's selected policy.
  3. Follow only reachable dependencies.
  4. Correct the smallest confirmed defect without weakening enforcement.
  5. Send a fresh test after DNS is visible.

Frequently asked questions

What does Gmail 451 4.7.24 mean?

Gmail considers one or more SPF entries suspicious and temporarily rate limits mail from the sending IP.

Should I delete an SPF include immediately?

No. First confirm whether the service is a legitimate sender and whether the term is reachable.

Can MailFixIt reproduce Gmail's rate limit?

No. It can identify relevant current SPF defects, but Gmail controls receiver policy and rate limiting.

Related email diagnostics

Gmail 550 5.7.24: The SPF record of the sending domain has one or more suspicious entriesFix Gmail 550 5.7.24 by checking the exact sending domain SPF record and correcting only confirmed syntax, dependency, or policy problems. SMTP 451 or 550 5.7.24: SPF validation errorDiagnose SMTP 5.7.24 SPF validation errors caused by DNS, syntax, dependencies, or temporary lookup failures. SPF terms after all are ignoredDiagnose SPF includes and redirects placed after all. Find unreachable sender authorization, reorder the policy safely, and verify the result.

Primary sources: Gmail SMTP errors and codes, RFC 7208 SPF.