Email Security

How secure is your
email domain?

Checks DMARC, DKIM, SPF, MX, MTA-STS and TLS-RPT for your domain — right from your browser, no sign-up.

Advanced: additional DKIM selectors

We automatically test ~40 common selectors (Google, Microsoft 365, SendGrid, Mailgun, ProtonMail, …). Add your own selectors here.

Background

Why email authentication is business-critical.

What is DMARC?

DMARC tells receiving mail servers what to do with messages that fail SPF or DKIM. Without DMARC, anyone can forge your domain in the From address.

Why does it matter?

Google and Microsoft have required DMARC for bulk senders since February 2024. Without authentication, marketing and transactional email lands in spam — or is rejected outright.

What are your next steps?

Start with p=none to monitor, review the reports for 2–4 weeks, then escalate to p=quarantine and p=reject. We guide you the whole way there.

Sentry0

Need help securing your domains?