Free Tools
Free DNS & Email Security Tools
No account required. No limits. Use these free tools to audit and improve your domain's email security and DNS configuration.
DNS Visualizer
Map SPF, DKIM, DMARC, and DNSSEC records visually. Instant DNS security audit.
Open tool
DMARC Checker & Generator
Check your DMARC record or generate a new policy to prevent email spoofing.
Open tool
SPF Record Checker
Validate SPF syntax, detect excessive lookups and missing -all policy.
Open tool
MTA-STS Validator
Verify your MTA-STS DNS record and policy file for encrypted email delivery.
Open tool
Bulk DNS Checker
Look up A, AAAA, MX, NS, CNAME, TXT, SOA, CAA records for multiple domains.
Open tool
Email ROI Calculator
Calculate revenue lost to poor email deliverability and spam folders.
Open tool
Need continuous monitoring?
ZeroHook automatically monitors your DNS configuration 24/7 and alerts you to changes, expiring certificates, and security issues before they affect your business.