Mini-Tool

DNS & Email Auth Checker

SPF, DMARC, DKIM, MX, and NS in one run. DKIM probes common selector names (DNS has no wildcard for selectors) — add an extra selector below if yours is custom.

Hostnames: the main scan uses the exact name you type (apex or a host such as mail.example.com). Optional Probe Common Subdomains runs a curated list of typical labels (www, mail, smtp, …) under that name — it is not a complete subdomain discovery service. Use Advanced for any specific hostname.

DomainExtra DKIM Selector

Probe Common Subdomains — check whether typical hostnames (www, mail, smtp, api, …) exist under the domain above (A/AAAA/MX/TXT/CNAME). Best with an apex like example.com; not exhaustive.

Server-side DNS. DKIM probes 41 common selectors; custom ESP keys may need the extra field.

Advanced: Raw TXT & CNAME Trace

Query any hostname. Optional CNAME chain following, then list TXT — same engine as the main scan.

Follow CNAMEs Before TXT

CNAME Trace → TXT at Terminal