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SPF Checker
Check any domain's SPF record for syntax errors, the 10-DNS-lookup limit, includes, and alignment. Free, instant, no signup.
This tool is being wired up. The analyzer ships in the next build phase.
About this check
Validate SPF syntax, includes, and the 10-lookup limit.
Frequently asked questions
- What does the SPF Checker actually check?
- Validate SPF syntax, includes, and the 10-lookup limit.
- Is this really free?
- Yes. Every on.bo tool is free, no signup required, no rate-limit tricks.
- Do you store the data I check?
- We log minimal metadata to keep the service healthy. Lookups themselves are not retained beyond short-term caching.