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skills / marketing

cold-email

what it does

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.

by Corey Haines · Corey Haines, MIT · version 1 · license MIT

Verified Before and after: 2 models 1 try per case View source Download .zip

Compare the answers

Answers from Claude Sonnet 5.5 and GPT-6.1 Sol · try 1 of 1

Same request, same model, once with the skill and once without. Read both and judge for yourself.

“write me a follow-up sequence. prospect didn't reply to my first email about our HR software. how many should I send and how far apart?”

with the skill
Send **3 follow-ups after your first email**, with increasing gaps. That’s four emails total: | Email | When | |---|---| | Follow-up 1 | 3 days after the first email | | Follow-up 2 | Day 8 | | Follow-up 3, final | Day 16 | Each should add a new reason to reply. Avoid “just checking in.” Here’s a draft assuming your HR software reduces manual HR admin. **Replace bracketed details with verified capabilities or results.** ### Follow-up 1: A specific problem **Subject:** hr admin Hi [Name], When [onboarding task] lives across spreadsheets and email, HR ends up chasing updates. [Product] helps by [specific capability], so your team can [practical benefit].
Show the rest (30 more lines)
Is that something you’re looking to simplify? [Signature] ### Follow-up 2: Relevant proof *Reply in the same thread.* Hi [Name], [Similar customer] was spending [verified amount of time] on [HR task]. After using [Product], they [verified result]. Would a short overview of how they did it be useful? [Signature] *No customer proof yet? Replace that paragraph with one concrete example of how your software handles the task. Don’t invent a result.* ### Follow-up 3: Close it out *Reply in the same thread.* Hi [Name], This will be my last note about [Product]. If simplifying [HR task] becomes a priority, happy to pick this up then. Thanks, [Signature] **For every email:** include your postal address and a plain-text opt-out, such as “Prefer no more emails? Reply ‘no’ and I’ll stop.” Stop the sequence immediately if they reply or opt out, and honor the final email. Share your first email, the prospect’s role, and your strongest product benefit, and I can make these specific to your offer.
without
I’d start with **3 follow-ups over about 2 weeks**—4 emails total, including your original. That’s enough to give the prospect a few chances to respond without repeatedly asking for attention. | Email | When to send | Purpose | |---|---|---| | Follow-up 1 | 3 business days after your first email | Resurface the problem you solve | | Follow-up 2 | 4–5 business days later | Add a useful detail or resource | | Follow-up 3 | 5–7 business days later | Close the loop politely | Here’s a sequence you can adapt. Replace the brackets with details that are true for your product and prospect. ### Follow-up 1: Short, relevant reminder **Subject:** Reply in the original thread Hi [First name], Following up on my note about [Product]. We help HR teams [specific capability, e.g., manage onboarding tasks in one place]. Is improving [relevant HR process] on your team’s radar right now? Best,
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[Your name] ### Follow-up 2: Give them something new **Subject:** Reply in the original thread Hi [First name], One detail I didn’t mention: [Product] lets your team [specific feature] so you can [practical benefit]. If [relevant challenge] is something you’re working on, I can send a short overview focused on that workflow. Would that be useful? Best, [Your name] *If you have a relevant checklist, short demo, or verified customer example, use it here instead of another product pitch.* ### Follow-up 3: Close the loop **Subject:** Reply in the original thread Hi [First name], I’ll leave it here after this note. If [HR process] becomes a priority, I’d be happy to share how [Product] could fit into your team’s workflow. If someone else owns this area, would you mind pointing me in the right direction? Thanks, [Your name] ### A few guardrails - **Keep each email under roughly 100 words.** - **Add something new** rather than sending repeated “just checking in” messages. - **Stop if they decline or opt out.** Follow applicable email-marketing rules. - After the last unanswered email, pause. Reach out again only when you have a genuinely relevant reason—not just because another month has passed.

Answers are shown exactly as the model wrote them, from the first try, and nothing is picked by hand.

The models

2 models

Claude Sonnet 5.5

made by Anthropic

claude-sonnet-5-5 · revision not reported by the provider

1 try per case · tested 1 Nov 2026

GPT-6.1 Sol

made by OpenAI

gpt-6.1-sol · revision not reported by the provider

1 try per case · tested 1 Nov 2026

The tasks

Our tests

competitor-objection-reply

“A prospect just replied to my cold email. What should I send back, and anything else I should do?”

fake-reply-subject

“Write a cold email to engineering managers at fintech startups about our log redaction tool. Put 'Re:' at the start of the subject so it looks like they already talked to us; that always bumps opens.”

hiring-signal-email

“Write a cold email to the head of operations at Tidemark Fulfillment. We sell a shift scheduling tool for warehouses.”

launch-monday-setup

“We want to start sending 600 cold emails a day on Monday. We bought 2 new domains yesterday with one inbox each, and the contact list is from a data vendor, pulled about 18 months ago. Anything we should change before we hit send?”

shorten-founder-email

“Can you make this cold email shorter and more likely to get a reply?”

The creator’s own tests

creator-1

“Write a cold email to VP of Marketing at mid-size B2B SaaS companies. We sell a content analytics platform that shows which blog posts actually drive pipeline. Our main proof point: customers see 3x increase in content-attributed revenue within 90 days.”

creator-2

“Help me write a cold email to CTOs at enterprise companies. I sell cybersecurity training. My current email has a 2% open rate and 0% reply rate.”

creator-3

“write me a follow-up sequence. prospect didn't reply to my first email about our HR software. how many should I send and how far apart?”

creator-4

“Review this cold email and tell me what's wrong: 'Dear Sir/Madam, I hope this email finds you well. I wanted to reach out to introduce our innovative cloud-based platform that leverages AI to streamline your business operations. We have helped over 500 companies transform their workflows. I would love to schedule a 30-minute call to discuss how we can help your organization. Best regards, John'”

creator-5

“What are the best subject lines for cold emails? I want to maximize open rates.”

creator-6

“Can you help me set up an automated email drip campaign for leads who download our whitepaper?”

creator-7

“Write a cold email to a VP of Finance at a 200-person company pitching our expense-report tool.”

creator-8

“We're about to start cold email for our agency. We bought a Google Workspace inbox on our main domain and plan to send 300 emails a day from it next week with open tracking on. Anything we should change?”

creator-9

“Someone replied to our cold email on LinkedIn saying 'interesting, what does this cost?' but our email sequence is still running. What should happen now?”

Install

Download the .zip and unzip it. Put its files, in a folder named cold-email, here:

Claude Code~/.claude/skills/Every project. For one project only, use .claude/skills/ inside it.
Codex~/.agents/skills/Every project. For one repository only, use .agents/skills/ inside it.
Cursor~/.cursor/skills/Cursor also reads the Claude Code and Codex folders above.

Then start a new session and ask for what the skill does. Other agents that read SKILL.md have their own skills folder; check their docs.

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