Security
Injection, dangerous content, phishing resistance, and secrets.
3 topics in this category.
Email Header Injection & CRLF Neutralization
RequiredPrevent SMTP and RFC 5322 header injection vulnerabilities by neutralizing CRLF control characters and using typed mail serialization libraries.
Secure Hyperlinks & Click-Tracking Integrity
RequiredEnforce HTTPS-only hyperlinks, eliminate phishing link text mismatches, and protect email click-tracking redirects against open redirect vulnerabilities using HMAC signatures.
Dangerous Content & Prohibited Email Elements
RequiredEliminate prohibited active content (JavaScript, iframes, embedded objects, raw forms) and restrict high-risk file attachment extensions to prevent malware classification.