How do I install the Cold Email Subject Lines skill?

Run npx skillmds@latest add cmj-hub/cold-email-subject-lines in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Cold Email Subject Lines safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Cold Email Subject Lines?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Cold Email Subject Lines free to use?

Yes. Installing skills from SkillMD is free. This skill is licensed under MIT.

Who published Cold Email Subject Lines?

cmj-hub (@cmj-hub) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Cold Email Subject Lines by cmj-hub

Name: Cold Email Subject Lines
Author: cmj-hub

Cold Email Subject Lines

Generate or critique cold-email subject lines across 4 framework families (pain, curiosity, social proof, direct). Each suggestion is ≤7 words, no spam triggers, no clickbait, includes reply-rate notes from the JMC Subject Line Swipe File (25 high-performers). Loaded by the main cold-email skill when the user asks for subject lines, openers, or to critique a draft subject.

cmj-hub Updated Sep 17, 2026

File contents

Cold Email Subject Lines — 4-Framework Pattern Library

Loaded by cold-email when the user wants subject-line suggestions or critique.

Activation triggers

"Subject lines for..."
"Subject line ideas"
"Critique this subject"
"Better subject than..."
"What's a good subject for..."

The 4 framework families

Framework	When to use	Example
Pain	Audience is problem-aware	"Pipeline gap after the Q3 hire freeze?"
Curiosity	Audience needs a hook before they'll open	"What tried after their Series B"
Social proof	Audience trusts other companies more than vendors	"How hit 40% reply rate"
Direct	Audience is short on time, you have a clear ask	"15 min Thursday re: demand gen?"

The skill's job: given a draft cold email (or a target audience + EVP), suggest 3-5 subject lines spanning at least 2 frameworks.

Constraints (every subject)

≤7 words (Gmail truncates around 30 chars mobile)
No ALL CAPS
No emojis (deliverability)
No Re: / Fwd: fakes (banned by bulk-sender rules)
No clickbait ("You won't believe...", "This one trick...")
No spam triggers — load references/spam-trigger-words.md for the list
Personalization (first name, company) where relevant — but not faked
Lowercase first letter often outperforms capitalized in B2B (test)

Workflow

1. Gather context

Input	Why needed
`audience` (PSP description)	Determines which framework family fits
`evp`	Anchors social-proof and pain framings
`intent` (open / reply / book)	Direct frameworks work better for booking
`relationship` (cold / re-engagement / referred)	Different opening patterns

2. Generate 5 suggestions

Default: 1-2 per framework family (3-5 total). Order by predicted fit, not framework alphabetical.

| # | Framework | Subject | Notes |
|---|---|---|---|
| 1 | Pain | "Pipeline gap after the freeze?" | Anchors PSP directly; for problem-aware audience |
| 2 | Social proof | "How <peer> hit 40% reply rate" | Best if you have the case study |
| 3 | Curiosity | "<peer> tried this after Series B" | If audience is skeptical of direct claims |
| 4 | Direct | "15 min Thursday re: demand gen?" | If they're warm or you have signal-based timing |
| 5 | Pain | "Q3 demand gen plan question" | Conservative; fits exec inboxes |

3. Spam-trigger lint

After generating, lint each subject against references/spam-trigger-words.md. Flag any that hit known triggers.

4. Critique mode

If user pastes a subject for critique, return:

Subject: "<original>"

Issues:
  - <issue 1>
  - <issue 2>

Better alternatives:
  - "<alt 1>" — <why>
  - "<alt 2>" — <why>

References

references/spam-trigger-words.md — banned words / phrases that hurt inbox placement
The 25 High-Performing Subject Lines PDF ships in the free Cold Email Linter — 25 patterns organized by framework with reply-rate notes from real campaigns
The full Cold Email & Outreach Craft course in The Compounding Engine:

---name: cold-email-subject-linesdescription: Generate or critique cold-email subject lines across 4 framework families (pain, curiosity, social proof, direct). Each suggestion is ≤7 words, no spam triggers, no clickbait, includes reply-rate notes from the JMC Subject Line Swipe File (25 high-performers). Loaded by the main cold-email skill when the user asks for subject lines, openers, or to critique a draft subject.license: MIT---# Cold Email Subject Lines — 4-Framework Pattern LibraryLoaded by `cold-email` when the user wants subject-line suggestions orcritique.## Activation triggers- "Subject lines for..."- "Subject line ideas"- "Critique this subject"- "Better subject than..."- "What's a good subject for..."## The 4 framework families| Framework | When to use | Example ||---|---|---|| **Pain** | Audience is problem-aware | "Pipeline gap after the Q3 hire freeze?" || **Curiosity** | Audience needs a hook before they'll open | "What <peer company> tried after their Series B" || **Social proof** | Audience trusts other companies more than vendors | "How <peer> hit 40% reply rate" || **Direct** | Audience is short on time, you have a clear ask | "15 min Thursday re: demand gen?" |The skill's job: given a draft cold email (or a target audience + EVP),suggest 3-5 subject lines spanning at least 2 frameworks.## Constraints (every subject)- ≤7 words (Gmail truncates around 30 chars mobile)- No ALL CAPS- No emojis (deliverability)- No `Re:` / `Fwd:` fakes (banned by bulk-sender rules)- No clickbait ("You won't believe...", "This one trick...")- No spam triggers — load `references/spam-trigger-words.md` for the list- Personalization (first name, company) where relevant — but not faked- Lowercase first letter often outperforms capitalized in B2B (test)## Workflow### 1. Gather context| Input | Why needed ||---|---|| `audience` (PSP description) | Determines which framework family fits || `evp` | Anchors social-proof and pain framings || `intent` (open / reply / book) | Direct frameworks work better for booking || `relationship` (cold / re-engagement / referred) | Different opening patterns |### 2. Generate 5 suggestionsDefault: 1-2 per framework family (3-5 total). Order by predictedfit, not framework alphabetical.```markdown| # | Framework | Subject | Notes ||---|---|---|---|| 1 | Pain | "Pipeline gap after the freeze?" | Anchors PSP directly; for problem-aware audience || 2 | Social proof | "How <peer> hit 40% reply rate" | Best if you have the case study || 3 | Curiosity | "<peer> tried this after Series B" | If audience is skeptical of direct claims || 4 | Direct | "15 min Thursday re: demand gen?" | If they're warm or you have signal-based timing || 5 | Pain | "Q3 demand gen plan question" | Conservative; fits exec inboxes |```### 3. Spam-trigger lintAfter generating, lint each subject against`references/spam-trigger-words.md`. Flag any that hit known triggers.### 4. Critique modeIf user pastes a subject for critique, return:```Subject: "<original>"Issues: - <issue 1> - <issue 2>Better alternatives: - "<alt 1>" — <why> - "<alt 2>" — <why>```## References- `references/spam-trigger-words.md` — banned words / phrases that hurt inbox placement- The **25 High-Performing Subject Lines** PDF ships in [the free Cold Email Linter](https://jaymountconsulting.com/tools/cold-email-linter) — 25 patterns organized by framework with reply-rate notes from real campaigns- The full **Cold Email & Outreach Craft** course in The Compounding Engine:

Frequently asked questions