Cold Email

Corey HainesCommunityCreated by Corey Haines

Skill
Workflow
Business and productivity
MIT
No issues found

From the author

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.

— the description by Corey Haines

AutoGineer summary

Written by AutoGineer from the skill’s own files, not by the author

This skill provides a structured approach to B2B cold outbound, focusing on human-centric communication that avoids common AI-generated pitfalls. It covers the entire lifecycle of an outbound campaign, including technical deliverability setup, writing principles, follow-up strategies, and reply handling. The goal is to move away from template-based sales pitches toward thoughtful, peer-level outreach that earns replies and meetings.

What it does

Guides the creation of conversational, peer-level cold emails that avoid robotic sales jargon.
Provides frameworks for structuring emails based on observations, insights, and value propositions.
Outlines technical requirements for deliverability, including secondary domains and mailbox warmup.
Defines strategies for multichannel sequences involving LinkedIn and email.
Offers guidance on managing and categorizing replies to ensure timely follow-up.
Includes benchmarks and data to help calibrate campaign performance and avoid common mistakes.

When to use it

When you need to initiate B2B cold outreach or prospecting campaigns.
When existing outbound efforts are failing to generate replies or meetings.
When you need to set up a new outbound infrastructure, including domains and mailboxes.
When you want to improve the quality and human tone of your sales copy.
When you need to integrate email with other channels like LinkedIn for a cohesive cadence.

Advantages

Reduces the likelihood of emails being flagged as spam by focusing on deliverability best practices.
Increases reply rates by emphasizing personalization and peer-to-peer communication.
Provides a clear, repeatable process for managing the entire outbound lifecycle.
Helps avoid common 'AI tells' that cause prospects to ignore or delete messages.
Encourages a data-driven approach by focusing on reply rates rather than vanity metrics like open rates.

Usage examples

“Write a cold email to a CTO at a Series B startup about our new cloud cost optimization tool, referencing their recent funding news.”: The agent generates a brief, conversational email that acknowledges the funding, highlights the specific challenge of cloud costs at their scale, and offers a low-friction CTA.
“My cold emails aren't getting replies. Can you review this sequence and suggest improvements?”: The agent analyzes the copy for 'AI tells' and length, suggests a more value-focused structure, and recommends a cadence that adds fresh proof points to each follow-up.

Install

Download the skill as a ZIP:
https://mp-staging.autogineer.com/agent-skills/coreyhaines31/cold-email/download

Unzip it into the cross-client skills folder of your project:

mkdir -p .agents/skills && unzip cold-email.zip -d .agents/skills

Documentation by Corey Haines

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):

Who are you writing to? — Role, company, why them specifically
What do you want? — The outcome (meeting, reply, intro, demo)
What's the value? — The specific problem you solve for people like them
What's your proof? — A result, case study, or credibility signal
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.

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:

benchmarks.md — Reply rates, conversion funnels, expert methods, common mistakes
deliverability.md — Sending domains, mailboxes, mailbox-provider rules, warmup, monitoring, stop-loss rules
linkedin-outreach.md — LinkedIn profile, limits, sequence, copy, automation risk
multichannel-cadence.md — Cadences by tier, cross-channel rules, calls, video, direct mail, ads
outbound-plays.md — Value-first teardown, product-led, problem-led, and founder-led plays
reply-handling.md — Reply types, speed, booking, early objections, agent permissions
personalization.md — 4-level personalization system, research signals
subject-lines.md — Subject line data and optimization
follow-up-sequences.md — Cadence, angles, breakup emails
frameworks.md — All copywriting frameworks with examples

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:

Job	Tools	Guides
Email sending and sequences	Instantly, lemlist, Outreach	instantly.md, lemlist.md, outreach.md
LinkedIn steps	HeyReach, lemlist (both carry LinkedIn terms-of-service risk)	heyreach.md
Verification before send	Truelist, Hunter	truelist.md, hunter.md
CRM and reply logging	HubSpot, Attio, Close	attio.md, close.md
Booking	Calendly, SavvyCal	calendly.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)

Files

ATTRIBUTION.mdAdded by AutoGineer881 B
LICENSELicence file added by AutoGineer1.0 KiB
SKILL.md12.3 KiB
evals/evals.json10.2 KiB
references/benchmarks.md6.3 KiB
references/deliverability.md7.6 KiB
references/follow-up-sequences.md3.9 KiB
references/frameworks.md5.3 KiB
references/linkedin-outreach.md5.6 KiB
references/multichannel-cadence.md5.4 KiB
references/outbound-plays.md6.0 KiB
references/personalization.md5.1 KiB
references/reply-handling.md4.5 KiB
references/subject-lines.md2.9 KiB

references/deliverability.md

Cold Email Deliverability

The best cold email does nothing if it lands in spam. Deliverability is set up before the first send and watched every week after. This reference covers the sending setup, the mailbox providers' rules, volume limits, warmup, monitoring, and when to stop.

Numbers here come mostly from sending-infrastructure vendors and mailbox providers' own guidelines. Mailbox providers change enforcement without notice, so treat the volume figures as starting points and let your own placement tests decide.

The rules from Google, Yahoo, and Microsoft

Provider	What it requires	Enforcement
Gmail	SPF and DKIM for everyone; for bulk senders (about 5,000+ messages a day to personal Gmail), also DMARC, alignment, one-click unsubscribe on marketing mail, and spam complaints under 0.3%	Since November 2025, non-compliant mail gets permanent rejections rather than temporary deferrals. Once you're classified as a bulk sender, the status is permanent
Yahoo	Matches Google's requirements	Since 2024
Microsoft (Outlook.com, Hotmail, Live)	SPF, DKIM, and DMARC for senders above 5,000 a day	Since May 5, 2025, non-compliant mail is rejected (`550 5.7.515`)

Google's bulk-sender rules apply to mail sent to personal Gmail accounts, not to Google Workspace business addresses. A cold program under 5,000 a day isn't technically a "bulk sender." Follow the rules anyway: they describe what every filter rewards, and the complaint threshold applies to everyone.

Complaint rate: keep spam complaints under 0.1% and never reach 0.3%. Practitioners report Workspace sending degrading well before 0.3%.

Sending setup

Never send cold email from your primary domain. One bad campaign can damage the domain your customers, invoices, and password resets depend on.

Buy secondary domains that are obviously yours (getacme.com, acmehq.com, tryacme.com). Redirect each to your main site.
Authenticate every domain: SPF, DKIM, and DMARC (start at p=none with reporting), aligned to the From domain. Add a custom tracking domain only if you track clicks (see Tracking, below).
Create 2–3 mailboxes per domain, each a real-looking person with a name, photo, and signature. Never use aliases of a single mailbox; both Google and Microsoft treat that as abuse of their terms.
Only buy mailboxes from properly licensed tenants. In late 2025 Google reportedly suspended large numbers of resold Workspace mailboxes built on education, nonprofit, or legacy accounts. Cheap "reseller" inboxes are disposable at best.
Match the provider to your prospects where you can. Google-hosted mailboxes for audiences on Google Workspace (most startups and SaaS), Microsoft-hosted for enterprise audiences on Microsoft 365. Vendors report better inbox placement when the two match. Check a prospect's mail host from their MX record.

Volume math

Setting	Starting point
Sends per mailbox per day	20–30 (Google-hosted); test lower for Microsoft-hosted, where 2026 operator reports range from single digits to dozens
Mailboxes per domain	2–3
Daily volume	Mailboxes × sends per mailbox

Example: 500 sends a day ≈ 20 mailboxes at 25 each ≈ 7–10 domains. Follow-ups count toward the daily volume.

Plan for spares. Keep 10–20% extra domains warmed and idle, so a burned domain can be swapped out without stopping the program.

Warmup

New mailboxes need 3–4 weeks of ramp before full cold volume:

Weeks 1–2: warmup only, plus a handful of real emails to people likely to reply.
Weeks 3–4: start cold sends at 5–10 a day per mailbox and increase gradually.
After that: keep light warmup running in the background.

Warmup networks still help new mailboxes, but a mailbox whose only engagement is warmup traffic is a recognizable pattern. Real replies are the strongest reputation signal there is, which is one more reason to write emails people answer.

The email itself

Plain text. No images, no HTML templates, no attachments.
No link in the first email, and at most one link in later ones. Never use link shorteners.
Turn off open tracking. Apple Mail Privacy Protection makes opens meaningless, and the tracking pixel itself is a spam signal. One large sender dataset found reply rates roughly doubled when open tracking was off. Measure replies instead.
Turn off click tracking unless you need it, and then only with a custom tracking domain.
Under about 80 words for the first email.
Vary the copy. Identical bodies across thousands of sends look like bulk mail. Segment-specific copy and real personalization fix this naturally. Keep spintax as a last resort.
Opt-out line. A plain-text line ("If this isn't relevant, reply 'no' and I won't follow up") plus your postal address in the signature. CAN-SPAM requires both; see the prospecting skill's compliance reference.

Verify before you send

Bounces are the fastest way to damage a domain. Keep them under 2% per campaign; under 1% is best in class. A single day with several percent bounces can trigger a review at Google.

Verify every list before upload, and re-verify anything older than about a week.
Handle catch-all domains with a policy. See the prospecting skill's sourcing and enrichment reference.
Pause any campaign automatically when its bounce rate passes 2%.

Monitoring

Check	How	When
Inbox placement	Seed tests (MailReach, GlockApps, or your sending tool's built-in test)	Before every new campaign and weekly
Domain reputation	Google Postmaster Tools; Microsoft SNDS	Weekly
Bounce rate	Sending tool, per campaign and per mailbox	Daily
Spam complaints	Postmaster Tools; replies containing "spam" or "stop"	Weekly
Blocklists	A blocklist checker for each sending domain	Weekly
Authentication	DMARC aggregate reports	Monthly

Stop-loss rules

Decide these before launch and enforce them automatically where your tool allows:

Trigger	Action
Bounce rate above 2% on a campaign	Pause the campaign and re-verify the list
Inbox placement below ~70% on a mailbox or domain	Pull it from rotation, return it to warmup, investigate
Spam complaints approaching 0.1%	Pause, cut volume, review targeting and copy
Domain appears on a major blocklist	Stop sending from it; delist or retire it
Reply rate under ~1% after 300+ sends	Stop the campaign; the targeting or offer is wrong, and more volume makes it worse

Common mistakes

Sending from the primary domain
Buying the cheapest reseller mailboxes and losing all of them at once
Skipping verification "because the data provider verified it"
Leaving open tracking on and optimizing for a number that isn't real
Scaling volume to fix a low reply rate
Running warmup and cold sends at full volume from day one

Tools

Job	Options
Sending and mailbox rotation	Instantly, Smartlead, lemlist, EmailBison, Salesforge
Domain and mailbox provisioning	Inframail, Maildoso, Mailforge, Truelist Outbound (managed domains, mailboxes, and a dedicated IP with an enforced ramp), Zapmail, or Google Workspace and Microsoft 365 directly
Placement testing	GlockApps, MailReach, or your sending tool's built-in test (Instantly has one)
Reputation	Google Postmaster Tools, Microsoft SNDS
DMARC monitoring	EasyDMARC, dmarcian, Valimail
List verification	Bouncer, MillionVerifier, NeverBounce, Truelist, ZeroBounce, and others

Setup guides: tools registry.

Requirements and compatibility

Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta

“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.

Security

No issues found by our static scan· No issues found

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Attribution and licence

Created by

Corey Haines

Publisher

Corey Haines (Community)

Source

coreyhaines31/marketingskills · skills/cold-email · commit 96798cf

Licence

MIT License (redistribution allowed)

LICENSE (added by AutoGineer from LICENSE)
ATTRIBUTION.md (written by AutoGineer)

Synced

2026-11-08

AutoGineer is not affiliated with or endorsed by Corey Haines.

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The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download cold-email.zip