Free email authentication tools
No signup, no email address. Results in plain English with the exact fix.
Checkers
Email domain health checkFree check of SPF, DKIM, DMARC, MX and HTTPS for any domain, with plain-English verdicts and the exact fix. No signup.SPF record checkerCheck any domain’s SPF record: syntax, duplicate records, +all, and the 10 DNS-lookup limit counted through every nested include. Free.SPF “too many DNS lookups” checkerSee exactly which includes push your SPF record past the 10 DNS-lookup limit, nested includes and all, and how to get back under it.DMARC record checkerCheck a domain’s DMARC record: policy (none, quarantine, reject), pct, reporting address and duplicate records, explained in plain English.DKIM record checkerLook up a DKIM key by selector, or let us try the common selectors for Google, Microsoft 365, SendGrid and more. Flags revoked and weak keys.MX record lookupLook up a domain’s MX records, check every mail server resolves, and spot null MX or missing records that cause lost replies and bounces.SSL certificate expiry checkerCheck when a domain’s HTTPS certificate expires, who issued it, and whether browsers trust it. Free, no signup.
Generators
SPF record generatorBuild a valid SPF record by ticking the services that send your email. Counts DNS lookups as you go so you stay under the limit of 10.DMARC record generatorCreate a DMARC record step by step: pick a policy, reporting address and alignment, then copy the exact TXT record to publish.