Free DNS & email authentication tools
Check MX, SPF, DKIM, DMARC, nameservers, WHOIS, and more instantly.
- DKIM Checker
- Validate a DKIM public key by domain and selector, including algorithm, size, and revocation status.
- DMARC Checker
- Review a domain's DMARC policy, alignment, reporting addresses, and enforcement.
- DNS Checker
- Look up A, AAAA, CNAME, MX, TXT, NS, CAA, and SOA records.
- Email Header Analyzer
- Inspect SPF, DKIM, and DMARC results, identify the sending IP, confirm reverse DNS, and trace the delivery path.
- MX Checker
- Find the mail servers that receive email for a domain and compare their priorities.
- Nameserver Checker
- Find a domain's authoritative nameservers and identify the DNS provider.
- PTR Checker
- Look up the reverse DNS (PTR) hostname for an IP address.
- SMTP TLS Checker
- Test mail servers for STARTTLS support, certificate validity, and negotiated TLS.
- SPF Checker
- Validate a domain's SPF policy, inspect mechanisms, and count DNS lookups.
- WHOIS/RDAP Checker
- Look up domain registration data, registrar, status, nameservers, and DNSSEC via RDAP.