SPF Checker · free
SPF record checker
Enter any domain to see its SPF record, the recursive include/redirect tree, and whether it stays under the 10-DNS-lookup limit that receivers enforce.
The 10-lookup rule
SPF records resolve recursively. Every include:, a, mx, redirect, and a few other mechanisms count toward a per-evaluation lookup budget of 10. Exceed 10 and receivers treat the SPF as permerror — effectively no SPF at all.
This tool walks the entire tree, counts every lookup, and flags records that will fail SPF evaluation. For a deeper explanation of how SPF fits with DKIM and DMARC, read our 2026 authentication setup guide.
Need this in production?
The free tool is great for one-off checks. For automated monitoring, alerting, and an API, see the related Postscale product.
See the Transactional Email API