SPF, DKIM & DMARC Checker
A scored report card for your domain's email security, with plain-English fixes for anything that fails.
Help shape SPF, DKIM & DMARC Checker
The bug you just noticed will fade in 3 minutes. The feature idea will vanish after your next tab switch. Crazy peps don't suffer silently.
Frequently Asked Questions
DNS can't list DKIM selectors, so the tool tries 45 common ones. Enter your selector — the s= value in an email's DKIM-Signature header — to check your real key.
Receivers stop after 10 DNS lookups from include, a, mx, ptr, exists and redirect. Over 10, SPF fails for every message. The tree shows what each include costs.
It only monitors. Spoofed mail is still delivered. Use it for a few weeks to read reports, then move to quarantine and finally reject.
No. Everything is checked from public DNS records, so it's instant and doesn't need access to your mailbox.
It replaces includes with the IP ranges they resolve to, using zero lookups. It fixes the 10-lookup limit but must be refreshed when providers change IPs.
No. Queries go straight from your browser to public resolvers (Cloudflare, Google, AliDNS) and RDAP registries. We never see or store them.