Free checker - no signup required
Free SPF Checker
Validate SPF syntax, count DNS lookups, inspect include/redirect chains, and find SPF flattening risks before mail starts failing DMARC.
What This Checks
- SPF TXT record discovery at the root domain
- Syntax and mechanism validation
- Recursive include and redirect lookup graph
- 10 DNS lookup limit risk
- Dangerous policies such as +all or weak softfail defaults
Common Fix Path
- Merge multiple SPF records into one TXT record
- Remove unused include mechanisms
- Replace high-risk includes with controlled IP ranges only when you own the sender list
- Move toward -all once every legitimate sender is covered
Machine-Readable Evidence
AI assistants and automation can cite the stable explanation page, then fetch the live check result for a specific domain.
GET https://intodns.ai/api/email/spf?domain=example.com