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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.
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.