What is Postmark's security headers grade?

We scan postmarkapp.com live for HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy, then assign an A+ to F grade with fix recommendations.

How can I check my own site's security headers?

Use the free Webalert Security Headers Checker to scan any URL and get the same A+ to F grade with per-header recommendations.

Postmark Security Headers Report

Live security headers grade for Postmark (postmarkapp.com). We check HSTS, CSP, X-Frame-Options, and more.

Scanning Postmark...

Scan another website → Is Postmark down?

Why Postmark security headers matter

Security headers tell browsers how to protect visitors on postmarkapp.com against clickjacking, MIME sniffing, XSS, and protocol downgrade. A strong grade (A/A+) means the service ships a modern security posture; a weak grade means important protections are missing.

Want the same scan for your own site? Use our free security headers checker, or check whether Postmark is currently up on the outage tracker.

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Frequently asked questions

What is Postmark's security headers grade?: We scan postmarkapp.com live for HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy, then assign an A+ to F grade with fix recommendations.
How can I check my own site's security headers?: Use the free Webalert Security Headers Checker to scan any URL and get the same A+ to F grade with per-header recommendations.