Free MTA-STS tool
MTA-STS validator.
Check your MTA-STS DNS record and policy file in one click. No account required.
- Validate _mta-sts TXT record presence and format
- Fetch and verify the policy file from your server
- 10 free checks per day, no login needed
_mta-sts lookup10 of 10 checks left today
Results appear here: the raw TXT record, the policy file, and what to change. Ten checks per day, no login.
Why MTA-STS?
Ensure encrypted email delivery.
MTA-STS prevents downgrade attacks and enforces TLS encryption for email in transit.
Prevent Downgrade Attacks
MTA-STS forces TLS encryption, stopping attackers from intercepting emails.
Improve Security Posture
Major providers support MTA-STS, strengthening your domain's email security.
Complements DMARC
Works alongside DMARC and SPF for comprehensive email security.
Go beyond one-off scans
Fix issues before they affect customers
Get automated monitoring, real-time alerts, and continuous scanning.
Free Account
- Copy-paste DNS fixes
- Daily automated scans
- Real-time alerts
- Full security audit
Deliverability
Full monitoring
- Copy-paste DNS fixes
- Daily automated scans
- Real-time alerts
- Full security audit
Free forever plan available · Paid plans from $29/mo