Free and open source · MIT · v2.7
The Email Marketing Bible
The email marketing skill for Claude, ChatGPT and any agent you run.
I wrote it because AI is bad at email. Ask a model for a welcome series and you get generic fluff. Ask about deliverability and it makes things up. So I put 908 sources and insights from 49 practitioners into one guide, then turned it into a skill your agent reads before it writes a word.
git clone https://github.com/CosmoBlk/email-marketing-bible.git ~/.claude/skills/email-marketing-bibleUsing ChatGPT, Codex or Cursor? Point it at the raw SKILL.md.
908 sources · 19 chapters · 4 appendices · 19 industry playbooks · 47 curated email designs · 49 practitioners · updated 8 September 2026
With the skill installed
What your agent can do once it knows email.
- 01
Builds the flows that make the money
Ask for a welcome series, abandoned cart, post-purchase or win-back flow. It comes back with the timing, the exit rules and the copy for every email, ready for you to check.
- Welcome
- Abandoned cart
- Post-purchase
- Win-back
- You approve
- 02
Audits what you already have
Point it at your account and it names the gaps: the flow you never built, the segment nobody mails, the DNS record that fails.
- 03
Works out why you're in spam
SPF, DKIM and DMARC first, then sender reputation, then content. In that order, every time.
- 04
Writes copy that sounds like you
Frameworks that convert, then an anti-slop pass that strips the phrases every model reaches for.
- 05
Designs emails worth opening
47 curated designs as references, built in MJML or React Email, with dark mode and mobile checked.
- 06
Knows your numbers
Open, click and revenue-per-email benchmarks for your vertical, from 19 industry playbooks.
- 07
Checks the law before the send
GDPR, CAN-SPAM, CASL and Australia's Spam Act, as a gate before anything goes out.
08Covers cold email, SMS, RCS and WhatsApp
Three chapters of their own, each with the rules for that channel.
It does the work. You keep the send button.
The full guide
19 chapters and 4 appendices, free to read.
About 88,000 words on emailmarketingskill.com. Start at the introduction or jump to the chapter you need.
- 1The Fundamentals
- 2Building Your List
- 3Segmentation & Personalisation
- 4The Emails That Make Money
- 5Copywriting That Converts
- 6Design & Technical
- 7Deliverability
- 8Testing & Optimisation
- 9Analytics & Measurement
- 10Compliance & Privacy
- 11Industry Playbooks
- 12Choosing Your Platform
- 13Cold Email & B2B Outbound
- 14WhatsApp Business
- 15SMS & RCS
- 16AI & Agentic Marketing
- 17Company Case Studies
- 18Expert Directory
- 19Best Email Designs 2026
Appendices
Pairs with Nitrosend
The skill knows email. Nitrosend lets your agent run it.
The skill tells your agent what good looks like. Connect Nitrosend's MCP server and the same agent builds the campaign, wires up the flow, defines the segment and checks your domain, inside your own account.
Campaigns and flows have their own approve step before anything goes live. The skill tells your agent to stop there and ask you.
claude mcp add --transport http nitrosend https://api.nitrosend.com/mcpClaude Desktop, Cowork or ChatGPT? Add https://api.nitrosend.com/mcp as a custom connector.
- Nitrosend MCPConnect Claude, ChatGPT, Codex, Cursor or Gemini and run the whole email stack from a prompt.
- Email for ClaudeSet up Claude Code, Claude Desktop or Cowork, then run flows, newsletters and transactional email.
- Email for agentsAgents that sign up, send and reply on their own, with Nitrosend as the email layer.
- 47 best email designsThe designs behind chapter 19, as a free Figma file.
FAQ
- What is the Email Marketing Bible?
- A free, open source email marketing guide that doubles as a skill for AI agents. 19 chapters and 4 appendices, about 88,000 words, built from 908 sources. The skill file (SKILL.md) is the version your agent reads before it plans, writes or sends anything.
- Is it free?
- Yes. It is MIT licensed, so you can use it, fork it or ship it inside your own product. The guide and the repo need no sign-up.
- How do I install it?
- In Claude Code, run the
git clonecommand at the top of this page. It lands in~/.claude/skills/email-marketing-bibleand Claude loads it whenever email comes up. For ChatGPT, Codex, Cursor or any other agent, point it at the raw SKILL.md on GitHub. - Do I need Nitrosend to use it?
- No. It works with Klaviyo, Mailchimp, Resend, beehiiv, Omnisend and any other email platform, or with no platform at all. Nitrosend is the platform I co-founded for running email from an agent, and the platform chapter says plainly that the two share a founder.
- How often is it updated?
- The current version is v2.7, updated 8 September 2026. Updates land in the GitHub repo first, so a
git pullin the skill folder keeps your agent current. - Where does the full guide live?
- On emailmarketingskill.com, free to read, with the source on GitHub. This page is Nitrosend's front door to it. Every chapter link above goes straight there.
The full guide is free on emailmarketingskill.com.
MIT licensed, with the source and the skill file on GitHub.
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