Security Guides
Plain-English guides to domain and website security.
Your SSL Checker Isn't Telling You Which TLS Versions Are Enabled
Most SSL checkers report the protocol that was negotiated, not which protocols your server still accepts. google.com still accepts TLS 1.0 — here is how to test properly.
Read more →SPF Too Many DNS Lookups: What PermError Means and How to Fix It
SPF is limited to 10 DNS lookups. Exceed it and authentication fails silently with a PermError. How to count yours and three ways to fix it.
Read more →Email Security Compliance: What PCI DSS, ISO 27001, Cyber Essentials and GDPR Require
What do the major compliance frameworks actually require for email security? DMARC, SPF, DKIM and TLS requirements explained for PCI DSS, ISO 27001, Cyber Essentials and GDPR.
Read more →GDPR and Email Security: Is Your Domain Compliant?
How GDPR Article 32 applies to email security. What SPF, DKIM, DMARC and TLS mean for GDPR compliance — and how to check your domain in seconds.
Read more →Cyber Essentials Email Security Checklist
What Cyber Essentials and Cyber Essentials Plus require for email security. SPF, DKIM, DMARC, TLS and security headers checklist for UK certification.
Read more →What is DMARC and How to Check if Your Domain Has It
DMARC, SPF, and DKIM explained — and how to check if your domain is protected against email spoofing.
Read more →What Can Go Wrong With an SSL Certificate
How to check your SSL certificate, what can go wrong, and how to fix common SSL issues before they affect your visitors.
Read more →How to Check Your Website's Security Posture in 60 Seconds
A plain-English guide to the five core areas of website security — and how to check all of them for free.
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