Managed MTA-STS & TLS Enforcement

Stop man-in-the-middle downgrade attacks (RFC 8461). SentraDMARC provides a stateless, high-availability policy server with sub-5ms resolution, eliminating the complexity of manual HTTPS policy hosting and certificate rotation.

mta-sts.txt
_mta-sts (DNS)
version: STSv1
mode: enforce
mx: *.google.com
max_age: 604800

// DNS Configuration

TXT_mta-sts.yourdomain.com
v=STSv1; id=20240101;

Beyond STARTTLS

Mandatory Encryption for Email

Traditional email encryption is opportunistic—attackers can downgrade it to plain text. MTA-STS stops this by forcing encrypted connections.

Force TLS

Tell external mail servers that you strictly require encryption. If they can't encrypt, they shouldn't send.

Prevent Downgrades

Stop man-in-the-middle attacks where hackers strip encryption from email traffic.

Zero-Config Hosting

We host the required HTTPS policy file for you, so you don't need to manage a separate web server.

Security in Action

The "Man-in-the-Middle" Trap

SMTP was never built for security. See how SentraDMARC seals the gap between your servers.

The Vulnerability

Step 01: The Trigger

A bank sends a sensitive password reset. The mail travels over standard SMTP, assuming your identity is correct.

Step 02: The Attack

A hacker intercepts the DNS request and points your mail server to hacker-server.com.

Outcome: Without enforced verification, the bank hands your secrets directly to the thief.

The Defense

Enforced Policy

SentraDMARC serves your authorized MX patterns at the edge. Senders verify who you are before delivery.

"Infrastructure mismatch! I will refuse delivery to this untrusted server rather than risking exposure."

The sender recognizes the trap and halts delivery, preserving 100% confidentiality.