Agent skill

Cold Email

by coreyhaines31 in coreyhaines31/marketingskills

Write and run B2B cold outbound that gets replies, from cold emails and follow-ups to sending setup, LinkedIn, multichannel cadences, and reply handling.

MITAuto-check passedSales & Support

Install Cold Email

skills CLI
$ npx skills add coreyhaines31/marketingskills --skill cold-email -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install coreyhaines31/marketingskills cold-email --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/coreyhaines31/marketingskills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/cold-email .claude/skills/cold-email && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
cold-email
GitHub stars
54k
Token cost
~3.1k tokens
SKILL.md length
1,393 words
Files
12 (incl. references)
Skills in repo
21
Repo updated
First seen
Licence
MIT

At a glance

Write and run B2B cold outbound that gets replies, from cold emails and follow-ups to sending setup, LinkedIn, multichannel cadences, and reply handling.

  • Works in 5 steps: Who are you writing to? — Role, company,… → What do you want? — The outcome… → What's the value? — The specific problem… → …
  • The user mentions cold email
  • SKILL.md covers Before Writing, Writing Principles, Voice & Tone and Structure, plus 10 more sections
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Cold Email is an agent skill from coreyhaines31/marketingskills. Write and run B2B cold outbound that gets replies, from cold emails and follow-ups to sending setup, LinkedIn, multichannel cadences, and reply handling. Use when the user mentions "cold email," "cold outreach," "outbound," "prospecting email," "SDR emails," "follow-up sequence," "nobody's replying," "email deliverability," "sending domains," "warm up inboxes," "LinkedIn outreach," "connection request message," "multichannel sequence," "cadence," "cold call," "voicemail," "handle replies," "AI SDR," "teardown…

Its SKILL.md is about 3.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 13 other files, including reference files (for example `evals/evals.json`, `references/benchmarks.md` and `references/deliverability.md`).

It sits in Sales & Support, covering Cold outreach. It works with LinkedIn. The repository describes itself as: Marketing skills for Claude Code and AI agents. CRO, copywriting, SEO, analytics, and growth engineering. The licence is MIT.

When your agent uses it

  • The user mentions cold email
  • Prospecting email
  • Follow-up sequence
  • Nobodys replying

Example prompts

  • “cold email,”
  • “cold outreach,”
  • “outbound,”
  • “/cold-email”

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

  1. Who are you writing to? — Role, company, why them specifically
  2. What do you want? — The outcome (meeting, reply, intro, demo)
  3. What's the value? — The specific problem you solve for people like them
  4. What's your proof? — A result, case study, or credibility signal
  5. Any research signals? — Funding, hiring, LinkedIn posts, company news, tech stack changes

What it can do on your machine

Read from SKILL.md and the folder at commit 1efedbc. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Cold Email loads about 3.1k tokens when it runs, and up to ~17k if it reads all its reference files. Until then it costs about 224 tokens; SKILL.md has 1,393 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~224
When it runs · the whole SKILL.md, loaded when a task matches
~3.1k
With references · SKILL.md plus every file in references/, read only if the agent opens them
~17k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from coreyhaines31/marketingskills at commit 1efedbc, republished under its MIT licence (© coreyhaines31). 1,393 words, ~3,125 tokens.

Download SKILL.mdSave it as .claude/skills/cold-email/SKILL.md (or your agent's skills folder). This skill also uses 11 other files; get the full folder from GitHub.
name
cold-email
description
Write and run B2B cold outbound that gets replies, from cold emails and follow-ups to sending setup, LinkedIn, multichannel cadences, and reply handling. Use when the user mentions "cold email," "cold outreach," "outbound," "prospecting email," "SDR emails," "follow-up sequence," "nobody's replying," "email deliverability," "sending domains," "warm up inboxes," "LinkedIn outreach," "connection request message," "multichannel sequence," "cadence," "cold call," "voicemail," "handle replies," "AI SDR," "teardown outreach," or "product-led outbound." Send from secondary domains, verify lists first, turn off open tracking, and stop every channel when a prospect replies. Copy avoids AI tells like 'it's not X, it's Y' reveals. For building the list and account research, see prospecting. For lifecycle email, see emails. For call scripts and sales collateral, see sales-enablement.
metadata.version
2.2.0

Cold Email Writing

You are an expert in cold outbound. Your goal is to write emails that sound like they came from a sharp, thoughtful human — not a sales machine following a template — and to make sure they reach the inbox, work alongside the other channels, and turn replies into meetings.

Before Writing

Check for product marketing context first: If .agents/product-marketing.md exists (or .claude/product-marketing.md, or the legacy product-marketing-context.md filename, in older setups), read it before asking questions. Use that context and only ask for information not already covered or specific to this task.

Understand the situation (ask if not provided):

  1. Who are you writing to? — Role, company, why them specifically
  2. What do you want? — The outcome (meeting, reply, intro, demo)
  3. What's the value? — The specific problem you solve for people like them
  4. What's your proof? — A result, case study, or credibility signal
  5. Any research signals? — Funding, hiring, LinkedIn posts, company news, tech stack changes

Work with whatever the user gives you. If they have a strong signal and a clear value prop, that's enough to write. Don't block on missing inputs — use what you have and note what would make it stronger.


Writing Principles

Write like a peer, not a vendor

The email should read like it came from someone who understands their world and isn't trying to sell them something. Use contractions. Read it aloud. If it sounds like marketing copy, rewrite it.

Every sentence must earn its place

Cold email is ruthlessly short. If a sentence doesn't move the reader toward replying, cut it. The best cold emails feel like they could have been shorter, not longer.

Personalization must connect to the problem

If you remove the personalized opening and the email still makes sense, the personalization isn't working. The observation should naturally lead into why you're reaching out.

See personalization.md for the 4-level system and research signals.

Lead with their world, not yours

The reader should see their own situation reflected back. "You/your" should dominate over "I/we." Don't open with who you are or what your company does.

One ask, low friction

Interest-based CTAs ("Worth exploring?" / "Would this be useful?") beat meeting requests. One CTA per email. Make it easy to say yes with a one-line reply.


Voice & Tone

The target voice: A smart colleague who noticed something relevant and is sharing it. Conversational but not sloppy. Confident but not pushy.

Calibrate to the audience:

  • C-suite: ultra-brief, peer-level, understated
  • Mid-level: more specific value, slightly more detail
  • Technical: precise, no fluff, respect their intelligence

What it should NOT sound like:

  • A template with fields swapped in
  • A pitch deck compressed into paragraph form
  • A LinkedIn DM from someone you've never met
  • An AI-generated email (avoid the telltale patterns: "I hope this email finds you well," "I came across your profile," "leverage," "synergy," "best-in-class")

Structure

There's no single right structure. Choose a framework that fits the situation, or write freeform if the email flows naturally without one.

Common shapes that work:

  • Observation → Problem → Proof → Ask — You noticed X, which usually means Y challenge. We helped Z with that. Interested?
  • Question → Value → Ask — Struggling with X? We do Y. Company Z saw [result]. Worth a look?
  • Trigger → Insight → Ask — Congrats on X. That usually creates Y challenge. We've helped similar companies with that. Curious?
  • Story → Bridge → Ask — [Similar company] had [problem]. They [solved it this way]. Relevant to you?

For the full catalog of frameworks with examples, see frameworks.md.


Subject Lines

Short, boring, internal-looking. The subject line's only job is to get the email opened.

  • 2-4 words, lowercase, no punctuation tricks
  • Should look like it came from a colleague ("reply rates," "hiring ops," "Q2 forecast")
  • No product pitches, no urgency, no emojis, no prospect's first name

See subject-lines.md for the full data.


Follow-Up Sequences

Each follow-up should add something new — a different angle, fresh proof, a useful resource. "Just checking in" gives the reader no reason to respond.

  • 3-5 total emails, increasing gaps between them
  • Each email should stand alone (they may not have read the previous ones)
  • The breakup email is your last touch — honor it

See follow-up-sequences.md for cadence, angle rotation, and breakup email templates.


Before You Send

Copy only matters if it reaches the inbox. Before the first send:

  • Send from secondary domains, never your primary one, with SPF, DKIM, and DMARC set up and mailboxes warmed for 3–4 weeks.
  • Verify every list right before upload and keep bounces under 2%.
  • Turn off open and click tracking. Measure replies.
  • Include a plain-text opt-out line and your postal address in every email.

Domain and mailbox math, the Google, Yahoo, and Microsoft rules, monitoring, and stop-loss thresholds are in deliverability.md.


Beyond Email

Most outbound that works in 2026 runs on more than one channel:

  • LinkedIn: profile, limits, the engage-then-connect sequence, message copy, and the automation decision. See linkedin-outreach.md.
  • Cadence: how email, LinkedIn, calls, video, and ads fit together by tier, and the rule that a reply on any channel stops all of them. See multichannel-cadence.md. Call scripts are in the sales-enablement skill.
  • Plays: value-first teardowns for services, product-led outbound for self-serve SaaS, problem-led outbound with a free sample, and founder-led outreach. See outbound-plays.md.
Show full SKILL.md (534 more words)Show less

When They Reply

Classify every reply (positive, information request, objection, not now, referral, out of office, unsubscribe), answer positive replies within minutes, and book with two proposed times plus a link. What an agent can handle alone and what needs a human is in reply-handling.md.


Quality Check

Before presenting, gut-check:

  • Does it sound like a human wrote it? (Read it aloud, and check for the AI tells below)
  • Would YOU reply to this if you received it?
  • Does every sentence serve the reader, not the sender?
  • Is the personalization connected to the problem?
  • Is there one clear, low-friction ask?

What to Avoid

  • Opening with "I hope this email finds you well" or "My name is X and I work at Y"
  • Jargon: "synergy," "leverage," "circle back," "best-in-class," "leading provider"
  • Feature dumps. One proof point beats ten features
  • AI tells, which prospects spot in the first line and delete:
    • Contrast reveals ("It's not about X, it's about Y") and "no X, no Y, no Z" lists
    • A claim followed by a comma and more restating clauses
    • Self-answered questions ("The result? 40% more meetings.") and colon reveals. A real question you want them to answer is fine
    • Stock phrases: "Here's the thing," "I'll be honest," "Quick question" as an opener, "Say goodbye to," "Unlock," "Take it to the next level"
    • Em dashes
    • For the full blacklist, use the copywriting skill's AI-tells reference
  • HTML, images, or multiple links
  • Fake "Re:" or "Fwd:" subject lines
  • Identical templates with only {{FirstName}} swapped
  • Asking for 30-minute calls in first touch
  • "Just checking in" follow-ups

Data & Benchmarks

The references contain performance data if you need to make informed choices:

Use this data to inform your writing — not as a checklist to satisfy.


Tool Integrations

For setup, see the tools registry, including its sales outbound quick start. Tools most used with this skill:

JobToolsGuides
Email sending and sequencesInstantly, lemlist, Outreachinstantly.md, lemlist.md, outreach.md
LinkedIn stepsHeyReach, lemlist (both carry LinkedIn terms-of-service risk)heyreach.md
Verification before sendTruelist, Huntertruelist.md, hunter.md
CRM and reply loggingHubSpot, Attio, Closeattio.md, close.md
BookingCalendly, SavvyCalcalendly.md, savvycal.md

Instantly's webhooks (reply received, lead interested, bounced, unsubscribed) are the simplest way to drive the cross-channel stop and reply triage from an agent.


  • prospecting: For building and qualifying the prospect list, signals, enrichment, verification, and account research — the natural upstream step before cold-email
  • copywriting: For landing pages and web copy
  • emails: For lifecycle/nurture email sequences (not cold outreach)
  • social: For LinkedIn and social posts
  • product-marketing: For establishing foundational positioning
  • revops: For lead scoring, routing, pipeline management, and the outbound stage model
  • sales-enablement: For cold call scripts, voicemails, and deal-stage objections
  • marketing-loops: For running outbound on a schedule (signal sweeps, reply triage, domain health, sequence reviews)

© coreyhaines31, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 11 other files (references) in skills/cold-email of coreyhaines31/marketingskills.

  • SKILL.md
  • evals/evals.json
  • references/benchmarks.md
  • references/deliverability.md
  • references/follow-up-sequences.md
  • references/frameworks.md
  • references/linkedin-outreach.md
  • references/multichannel-cadence.md
  • references/outbound-plays.md
  • references/personalization.md
  • references/reply-handling.md
  • references/subject-lines.md

Open the folder on GitHubat commit 1efedbc

Compare with similar skills

Cold Email next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Cold Email compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Cold Email this skillcoreyhaines31/marketingskills54k—~3.1kAutomated safety check: PassMIT
Sales OsromangojiberryAI/gojiberryai-sales-os139—~2kAutomated safety check: PassMIT
Cold Outreach Personalizeraiskilloftheweek/claude-ai-skill-of-the-week149—~2.6kAutomated safety check: PassNone
B2B Lead Generationminhnv0807/ai-business-skills609—~1.2kAutomated safety check: PassMIT
Cold Outreach Sequence BuilderBrianRWagner/ai-marketing-claude-code-skills441—~1.9kAutomated safety check: PassNone
Outreachyc-software/recruiting115—~3kAutomated safety check: NotesNone

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Works with

Categories

Questions about Cold Email

What does Cold Email do?

Write and run B2B cold outbound that gets replies, from cold emails and follow-ups to sending setup, LinkedIn, multichannel cadences, and reply handling. Cold Email is an agent skill from coreyhaines31/marketingskills. Write and run B2B cold outbound that gets replies, from cold emails and follow-ups to sending setup, LinkedIn, multichannel cadences, and reply handling.

When should I use Cold Email?

Cold Email fits situations like: the user mentions cold email; prospecting email; follow-up sequence; nobodys replying.

How do I install Cold Email in Claude Code?

Run `npx skills add coreyhaines31/marketingskills --skill cold-email -a claude-code`. Or copy the skill folder (skills/cold-email in coreyhaines31/marketingskills) into .claude/skills/cold-email in your project. Claude Code loads it when a task matches its description.

How do I install Cold Email in Codex?

Run `npx skills add coreyhaines31/marketingskills --skill cold-email -a codex`. Or copy the skill folder (skills/cold-email in coreyhaines31/marketingskills) into .agents/skills/cold-email in your project. Codex loads it when a task matches its description.

Can I use Cold Email in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add coreyhaines31/marketingskills --skill cold-email -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/cold-email, .gemini/skills/cold-email, .github/skills/cold-email and .opencode/skills/cold-email in your project.

What does Cold Email need to run?

SKILL.md names no scripts, command-line tools or credentials: Cold Email is instructions for the agent only.

Does Cold Email access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Cold Email safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Cold Email use?

Cold Email is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Cold Email use?

About 3.1k tokens (SKILL.md is roughly 13k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 13k tokens, read only when the agent opens those files.

What are the alternatives to Cold Email?

Skills that share tags, products or a category with Cold Email: Sales Os (romangojiberryAI/gojiberryai-sales-os, 139 stars), Cold Outreach Personalizer (aiskilloftheweek/claude-ai-skill-of-the-week, 149 stars), B2B Lead Generation (minhnv0807/ai-business-skills, 609 stars) and Cold Outreach Sequence Builder (BrianRWagner/ai-marketing-claude-code-skills, 441 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Cold Email?

coreyhaines31 (a GitHub user) maintains it in coreyhaines31/marketingskills, which has 53,967 GitHub stars. The repository holds 21 skills in this directory. The repository was last updated on October 8, 2026.

Source: coreyhaines31/marketingskills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.