Configures SPF, DKIM, and DMARC DNS TXT records to authenticate outbound email, prevent domain spoofing, and enforce a rejection/quarantine policy on unauthenticated mail, including auditing a domain's current DNS state. Use when hardening a domain's email security posture or defending against phishing and spoofing attacks.
Install
npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-dmarc-dkim-spf-email-securitynpx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-dmarc-dkim-spf-email-security -a claude-code -gnpx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-dmarc-dkim-spf-email-security -a codex -ggemini skills install https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git --path skills/implementing-dmarc-dkim-spf-email-securitygh skill install mukul975/Anthropic-Cybersecurity-Skills implementing-dmarc-dkim-spf-email-securitygit clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills /tmp/mukul975__Anthropic-Cybersecurity-Skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/mukul975__Anthropic-Cybersecurity-Skills/skills/implementing-dmarc-dkim-spf-email-security ~/.claude/skills/implementing-dmarc-dkim-spf-email-security # Claude Code
cp -R /tmp/mukul975__Anthropic-Cybersecurity-Skills/skills/implementing-dmarc-dkim-spf-email-security ~/.agents/skills/implementing-dmarc-dkim-spf-email-security # Codex, Cursor, Gemini CLI, Copilot, OpenCode