Email Marketing Bible

Email Marketing Bible is a free, open-source email marketing guide written by George Hartley, co-founder of Nitrosend, and packaged as a skill file (SKILL.md) that AI agents read before planning, writing or sending email. The current version is v2.7, updated 8 September 2026, and it is released under the MIT license.

The project's own description is that it was built from 908 sources and insights from 49 practitioners, with 19 chapters, 4 appendices, 19 industry playbooks and 47 curated email designs.

What It Is

The Email Marketing Bible is a reference and operating manual for AI agents doing email work. The skill has two parts: an operating manual for when the agent is acting (building, sending, diagnosing, designing) and a dense reference with benchmarks, frameworks and playbooks. It is installed by cloning the repository into the Claude Code skills folder, or by pointing other agents such as ChatGPT, Codex or Cursor at the raw SKILL.md file. The full guide, about 88,000 words, is also readable on emailmarketingskill.com.

What the Skill Helps an Agent Do

• Build welcome, abandoned cart, post-purchase and win-back flows, with timing, exit rules and copy for each email.
• Audit existing flows, segments, deliverability and compliance, and name what is missing.
• Draft copy with frameworks such as PAS, AIDA and BAB, then run an anti-slop pass to strip common AI phrasing.
• Direct email design with a Discover, Define, Deliver method, outputting inbox-safe MJML or React Email.
• Triage deliverability in order: authentication (SPF, DKIM, DMARC), then reputation, then content.
• Check GDPR, CAN-SPAM, CASL, CCPA and the Australian Spam Act as a gate before sending.
• Cover cold email, WhatsApp, SMS and RCS, and pull industry benchmarks by vertical.

Send Safety and ESP Control

The skill includes a hard gate: no send or schedule to more than one recipient without explicit human approval in the conversation. It can guide an agent operating Klaviyo, Resend, beehiiv, Mailchimp, Omnisend or Nitrosend through MCP and connectors, with pre-send gates and field-tested operating rules. It works with any email platform or none; Nitrosend's MCP server is an optional pairing, and the page discloses that the guide and Nitrosend share a founder.

Current Status

v2.7 added an AI email design method, five more practitioners in the expert directory, field notes from running an ESP through agents, updated model references and a skill file cut by a fifth, with send-safety gates unchanged. Updates land in the GitHub repository first, so a git pull keeps the installed skill current.