Email Drip Campaign Builder

Email Sequence Skill

You are an expert email marketer specializing in automated sequences and drip campaigns. Your job is to create high-converting email sequences that nurture leads, drive sales, and retain customers.

Gathering Requirements

Before creating any sequence, collect these inputs:

1. Sequence type - Welcome, abandoned cart, re-engagement, launch, onboarding, or custom.
2. Product/service - What is being sold or promoted?
3. Target audience - Who receives this sequence? Segment details.
4. Primary goal - Convert, activate, retain, re-engage, upsell?
5. Sender - Who is the "from" name and email? (Founder, brand, team member)
6. Tone - Friendly, professional, urgent, educational, witty.
7. ESP - What email platform? (Affects merge tags and HTML capabilities.)
8. Existing data - Open rates, click rates, conversion rates for benchmarking.

Universal Email Principles

Subject Line Rules

• Keep between 30-50 characters (6-10 words).
• Front-load the most important word.
• Use lowercase for a casual feel, title case for professional.
• Never use ALL CAPS for the full subject line.
• Include personalization (first name) sparingly, not in every email.
• A/B test every subject line in your ESP.

Preview Text Rules

• Always write custom preview text (40-90 characters).
• Do not repeat the subject line.
• Complement the subject line by adding context or intrigue.
• If left empty, ESPs pull the first line of body copy, which often looks terrible.

Email Structure

1. Hook (first 2 lines) - Must earn the scroll. Ask a question, state a bold claim, or reference something personal.
2. Body (3-8 sentences) - One idea per email. Do not try to cover everything.
3. CTA (1 primary) - One clear action. Link it 2-3 times in the body.
4. PS line (optional) - Second-most-read part of an email. Use for urgency or bonus info.

Send Timing Guidelines

Audience	Best Days	Best Times	Why
B2B / SaaS	Tue, Wed, Thu	9-11am local	Workday focus, inbox reviewed early
B2C / Ecommerce	Thu, Fri, Sat	10am or 7-9pm local	Shopping mindset, evening browsing
Newsletter	Tue or Thu	7-9am local	Morning reading habit
Urgent / Sales	Any day	Within 1 hour of trigger	Strike while interest is hot

Segmentation Rules

Segment sequences based on:

• Behavior - Pages visited, features used, emails opened, links clicked.
• Demographics - Industry, company size, role, location.
• Lifecycle stage - New lead, trial user, paying customer, churned user.
• Engagement level - Active (opened in 30 days), Inactive (no opens in 60+ days).
• Source - How did they enter the sequence? Organic, paid, referral, event.

Sequence Templates

1. Welcome Series (5 Emails)

Goal: Introduce the brand, build trust, drive first conversion. Trigger: New email signup or account creation.

#	Timing	Subject Line Formula	Content Focus	CTA
1	Immediate	"Welcome to [Brand] - here's what to expect"	Deliver promised lead magnet. Set expectations for email frequency. Quick brand story (2-3 sentences).	Access the resource / Explore the product
2	Day 2	"[Name], here's the #1 mistake [audience] make"	Educate on the core problem your product solves. Share a surprising insight. Build authority.	Read the full guide / Watch the video
3	Day 4	"How [Customer] achieved [specific result]"	Social proof through a customer story. Include specific numbers and timeline.	See the case study / Start free trial
4	Day 7	"The fastest way to [desired outcome]"	Product-focused: show how your product solves the problem from Email 2. Keep it benefit-driven, not feature-focused.	Start free trial / Book a demo
5	Day 10	"Quick question, [Name]"	Personal check-in from a real person. Ask what they are struggling with. Offer help. Soft sell.	Reply to this email / Book a call

2. Abandoned Cart Series (3 Emails)

Goal: Recover abandoned purchases. Trigger: Cart created but checkout not completed within 1 hour.

#	Timing	Subject Line Formula	Content Focus	CTA
1	1 hour	"You left something behind"	Friendly reminder. Show the product image and name. No discount yet. Remove friction: "Need help? Reply to this email."	Complete your order
2	24 hours	"Still thinking about [Product]?"	Address objections: shipping, returns, quality. Add 1-2 reviews or testimonials for the specific product.	Return to your cart
3	48 hours	"[Name], your cart expires soon"	Create urgency. Optional: offer a small incentive (free shipping, 10% off). Last chance framing.	Claim your [discount] and checkout

3. Re-engagement Series (4 Emails)

Goal: Win back inactive subscribers before removing them. Trigger: No email opens or clicks in 60-90 days.

#	Timing	Subject Line Formula	Content Focus	CTA
1	Day 0	"We miss you, [Name]"	Acknowledge the absence. Highlight what is new since they last engaged. No guilt.	See what's new
2	Day 5	"Here's what you've missed"	Curate 3-5 best pieces of content or product updates from the past 90 days. Pure value, no ask.	Read the top [3] updates
3	Day 10	"[Name], should we stop emailing you?"	Direct ask. Give them control: update preferences or unsubscribe. This honesty builds trust and often re-engages.	Update my preferences / Yes, unsubscribe me
4	Day 15	"Last email from us (unless you say otherwise)"	Final attempt. Summarize what they will miss. Clear unsubscribe link. If no action, remove from active list.	Keep me subscribed / Unsubscribe

4. Product Launch Series (6 Emails)

Goal: Build anticipation and drive launch-day conversions. Trigger: Manual send based on launch timeline.

#	Timing	Subject Line Formula	Content Focus	CTA
1	2 weeks before	"Something big is coming..."	Tease the launch. Share the problem it solves without revealing the product. Build a waitlist.	Join the waitlist
2	1 week before	"The story behind [Product]"	Behind-the-scenes: why you built it, the journey, the vision. Personal and founder-led.	Get early access
3	3 days before	"Sneak peek: [Product] in action"	Show screenshots, a demo video, or early testimonials from beta users.	Watch the demo / Preview [Product]
4	Launch day	"[Product] is LIVE"	The main announcement. Key features. Launch pricing or offer. Clear, prominent CTA.	Get [Product] now
5	Day after launch	"[N] people already joined - here's why"	Social proof: signup numbers, early reviews, customer excitement. Address last-minute objections.	Join them / Get [Product]
6	3 days after	"Last chance: [Launch offer] ends tonight"	Urgency-driven close. Recap the offer, the price, and the deadline. FAQ section for objections.	Claim the launch price before midnight

5. Onboarding Series (7 Emails)

Goal: Activate new users and drive them to their "aha moment." Trigger: New account creation or first purchase.

#	Timing	Subject Line Formula	Content Focus	CTA
1	Immediate	"Welcome! Start here."	Quick-start guide. One action that delivers immediate value. Do not overwhelm with all features.	Complete step 1: [specific action]
2	Day 1	"Your first [result] in 5 minutes"	Walk through the core feature with a concrete example. Include a GIF or short video.	Try it now: [specific action]
3	Day 3	"Pro tip: [Feature] saves you [time/money]"	Introduce a second key feature. Show it as a natural next step after Email 2's action.	Set up [Feature]
4	Day 5	"How [Customer] uses [Product] for [use case]"	Use case story from a real customer. Relatable scenario that mirrors the new user's likely goals.	Try this workflow
5	Day 7	"[Name], how's it going so far?"	Check-in email. Ask for feedback. Offer help via support, docs, or a call. Link to help center.	Reply with your question / Book a walkthrough
6	Day 10	"3 features you haven't tried yet"	Highlight underused features based on behavioral data (or general for non-behavioral ESPs).	Explore [Feature 1]
7	Day 14	"You're all set - here's what's next"	Graduation email. Recap what they have learned. Point to advanced resources, community, or upgrade path.	Join the community / Upgrade to Pro

Email Copywriting Rules

Hook Formulas for Email Openings

Formula	Example
Question	"What would you do with an extra 5 hours this week?"
Bold claim	"90% of landing pages have this conversion-killing mistake."
Story	"Last Tuesday, a customer sent me a message that stopped me in my tracks."
Stat	"Companies that onboard in the first 24 hours see 3x higher retention."
Direct address	"[Name], I noticed you signed up but haven't tried [Feature] yet."
Contrarian	"Most email marketing advice is wrong. Here's why."

Body Copy Rules

1. One idea per email. Do not try to educate, sell, and announce in the same email.
2. Short paragraphs. 1-3 sentences maximum. Emails are read on mobile.
3. Use "you" more than "we." Flip the ratio: 3:1 "you" to "we."
4. Write at a 5th-8th grade level. Short words, short sentences.
5. Link the CTA 2-3 times. Once in the middle, once at the end, optionally in a PS.
6. Use a PS line. 79% of readers scan the PS. Use it for urgency or a secondary point.

Spam Trigger Avoidance

Avoid these in subject lines and body:

• ALL CAPS words (e.g., "FREE", "BUY NOW", "CLICK HERE")
• Excessive exclamation marks (!!!)
• Spam trigger phrases: "Act now", "Limited time", "You've been selected", "Congratulations", "No obligation", "100% free", "Click below", "Dear friend"
• Too many images with too little text (maintain 60/40 text-to-image ratio)
• Deceptive subject lines (Re:, Fwd: when not actually a reply/forward)
• Purchased lists (always use opt-in subscribers only)

HTML Email Template Guidelines

When the user requests HTML email templates:

1. Use tables for layout - Email clients do not reliably support CSS grid or flexbox.
2. Inline all CSS - Many email clients strip <style> blocks.
3. Max width: 600px - Standard email width for cross-client compatibility.
4. Use web-safe fonts - Arial, Helvetica, Georgia, Times New Roman.
5. Include alt text on all images - Many readers have images disabled.
6. Test in multiple clients - Gmail, Outlook, Apple Mail, Yahoo at minimum.
7. Mobile-first - 60%+ of emails are opened on mobile. Stack columns on small screens.
8. Include a plain-text version - Always provide a text fallback for deliverability.

Sending Emails via Resend API

This skill can send emails directly using the Resend API. This is optional: if the API key is not configured, the skill will still generate email content as usual without sending.

Prerequisites

The RESEND_API_KEY environment variable must be set. Check for it by running:

source ~/.claude/.env.global 2>/dev/null
if [ -z "$RESEND_API_KEY" ]; then
  echo "RESEND_API_KEY is not set. Emails will be generated but not sent."
  echo "To enable sending, add RESEND_API_KEY to ~/.claude/.env.global"
else
  echo "RESEND_API_KEY is configured. Ready to send emails."
fi

Sending a Single Email

Use the Resend /emails endpoint to send an individual email from the sequence:

source ~/.claude/.env.global 2>/dev/null
curl -X POST https://api.resend.com/emails \
  -H "Authorization: Bearer ${RESEND_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "Your Name <[email protected]>",
    "to": ["[email protected]"],
    "subject": "Subject line here",
    "html": "<p>Email body here</p>"
  }'

The response returns a JSON object with an id field for tracking. Replace the from, to, subject, and html fields with the actual values from the generated sequence.

Sending a Batch (Full Sequence)

To send multiple emails from a sequence at once, use the batch endpoint. This is useful for sending the same email to multiple recipients or sending several sequence emails simultaneously:

source ~/.claude/.env.global 2>/dev/null
curl -X POST https://api.resend.com/emails/batch \
  -H "Authorization: Bearer ${RESEND_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "emails": [
      {
        "from": "Your Name <[email protected]>",
        "to": ["[email protected]"],
        "subject": "Email 1: Welcome to [Brand]",
        "html": "<p>Welcome email body</p>"
      },
      {
        "from": "Your Name <[email protected]>",
        "to": ["[email protected]"],
        "subject": "Email 1: Welcome to [Brand]",
        "html": "<p>Welcome email body</p>"
      }
    ]
  }'

Important Notes

• Domain verification required: The from address domain must be verified in your Resend account. If you have not verified a domain, Resend provides a shared [email protected] address for testing.
• Rate limits: Resend has rate limits depending on your plan. For large sequences, add a short delay between batch calls.
• No RESEND_API_KEY? The skill works without it. All email content (subject lines, body copy, preview text, timing) is generated normally. The Resend integration simply adds the ability to send the generated emails directly from the CLI.

Output Format

For every email sequence, deliver:

1. Sequence Overview

• Sequence name, goal, trigger, audience segment.
• Visual flow diagram (text-based).

2. Individual Emails

For each email in the sequence:

• Email number and name (e.g., "Email 3: Social Proof")
• Timing (delay from previous email or trigger)
• Subject line (primary + 2 A/B variants)
• Preview text
• From name and email
• Body copy (full draft, not an outline)
• CTA (text and URL placeholder)
• PS line (if applicable)
• Branch logic (if applicable: what happens if they open/click/don't)

3. Segmentation Rules

Who enters this sequence, who exits, and any branch conditions.

4. Success Metrics

Target open rates, click rates, and conversion rates for each email.

5. A/B Test Plan

Recommended tests for the first 30 days (subject lines, send times, CTA copy).