A comprehensive, data-backed email marketing guide built from 908 sources and 4,798 extracted insights. 16 chapters. 44 expert practitioners cited. 19 industry playbooks. Honest platform comparisons with zero affiliate links. Install it as a Claude Code skill with one command, and Claude becomes an email marketing co-pilot that audits your setup, drafts sequences, pulls industry benchmarks, and gives recommendations grounded in real sources. Free. Open-source. No paywall. No email gate.