Email marketing
Skill Mattakushi432/Claude-Code-Skills-Custom-DevTools-Pack/plugins/devtools-pack/skills/email-marketing
When to activate: email sequences, email campaigns, subject lines, drip campaigns, email automation, deliverability, segmentation, re-engagementFrom its SKILL.md
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Email Marketing
Subject Line Formulas
High-Converting Patterns
| Formula | Example |
|---|---|
| Number + Benefit | "7 ways to cut churn by 40%" |
| Question (pain) | "Still losing leads at checkout?" |
| Curiosity gap | "We found something weird in your data" |
| Social proof | "How [Company] grew to 10k users in 90 days" |
| Urgency + Scarcity | "Last 24 hours: 40% off ends tonight" |
| Personalization | "[Name], your account needs attention" |
| Controversy | "Cold outreach is dead (here's what works)" |
Rules
- 30-50 characters for mobile preview
- Avoid spam triggers: FREE, !!!, ALL CAPS, "guaranteed"
- A/B test subject lines on 20% of list before full send
- Preview text (preheader) should complement, not repeat subject
Email Sequence Architecture
Welcome Series (Days 0-7)
Day 0: Welcome + what to expect (immediate)
Day 1: Your #1 quick win (value delivery)
Day 3: Social proof + case study
Day 5: Core product/service education
Day 7: Soft CTA → next step or upgrade
Onboarding Series (SaaS)
Day 0: Account created — setup checklist
Day 1: Did you complete Step 1? (triggered)
Day 3: Feature spotlight #1 + video walkthrough
Day 5: Success story from similar user
Day 7: "Are you stuck?" offer help
Day 14: Usage check — power users vs inactive
Day 21: Case study + upsell to higher tier
Nurture Series (Lead → Customer)
Email 1: Educational content (no pitch)
Email 2: Problem agitation + framework
Email 3: Case study (prove it works)
Email 4: FAQ / objection handling
Email 5: Soft offer + trial/demo CTA
Email 6: Hard offer + urgency/deadline
Email 7: Last chance + scarcity
Re-engagement Series
Email 1: "We miss you" — simple, personal tone
Email 2: Best content they missed
Email 3: Survey — what can we do better?
Email 4: Final offer — exclusive discount
Email 5: "This is goodbye" + unsubscribe confirmation
Rule: Sunset unengaged subscribers after 90 days inactivity.
Segmentation Strategy
Behavioral Segments
| Segment | Criteria | Message |
|---|---|---|
| New subscribers | <7 days | Welcome series |
| Engaged | Opened in last 30d | New features, upsells |
| At-risk | No opens in 60-90d | Re-engagement |
| Churned | No opens in 90d+ | Win-back or sunset |
| Customers | Purchase tag | Onboarding, upsell |
| High LTV | Top 20% spend | VIP treatment |
| Trial users | In trial | Conversion sequence |
Demographic Segments
- Industry vertical → relevant case studies
- Company size → SMB vs Enterprise messaging
- Role (founder vs marketer vs developer) → feature emphasis
- Geography → timezone send optimization, local events
Engagement Score Formula
Score = (Opens × 1) + (Clicks × 3) + (Purchases × 10) - (Days since last activity × 0.1)
Deliverability
Technical Setup (Required)
- SPF record:
v=spf1 include:sendgrid.net ~all - DKIM: 2048-bit key, verified in DNS
- DMARC:
v=DMARC1; p=quarantine; rua=mailto:[email protected] - Custom sending domain (not shared IP for >10k sends/mo)
- Dedicated IP (when list >50k and sending consistently)
List Health
- Double opt-in for new subscribers (improves quality 2-3x)
- Remove hard bounces immediately
- Remove soft bounce addresses after 3 bounces
- Suppress unsubscribes within 10 business days (CAN-SPAM)
- Run list through validation service quarterly (ZeroBounce, NeverBounce)
Sender Reputation Rules
- Maintain open rate > 20%
- Keep spam complaint rate < 0.08% (Google/Yahoo threshold)
- Warm up new IPs: start at 500/day, double weekly
- Send to most engaged first when warming
Inbox Placement Testing
Tools: GlockApps, Mail-Tester, Litmus Spam Testing Test before sends over 10k: check spam score, inbox vs promo vs spam folder
A/B Testing Framework
What to Test (Priority Order)
- Subject line (biggest impact)
- From name / sender
- Send time / day
- CTA button text and color
- Email length (short vs long)
- Plain text vs HTML
- Personalization tokens
Test Methodology
- Minimum sample size: 1,000 per variant (500 minimum if small list)
- Test ONE variable at a time
- Statistical significance: 95%+ confidence
- Run for minimum 4 hours before declaring winner
- Document results in testing log
Split Test Calculator
Required sample = (Z² × p × (1-p)) / E²
where Z=1.96 (95% confidence), p=baseline rate, E=minimum detectable effect
Email Metrics & Benchmarks
| Metric | Good | Great | How to improve |
|---|---|---|---|
| Open rate | 20-25% | 35%+ | Subject line, sender name, list quality |
| Click rate | 2-3% | 5%+ | CTA clarity, content relevance |
| Click-to-open | 10-15% | 20%+ | Email body copy, offer strength |
| Unsubscribe rate | <0.5% | <0.2% | Segmentation, frequency |
| Spam complaints | <0.08% | <0.02% | Relevance, easy unsubscribe |
| Conversion rate | 1-2% | 5%+ | Offer + landing page alignment |
Email Copywriting Template
Structure
[Subject: Pattern from formulas above]
[Preheader: Complement, don't repeat subject]
[Opening hook: 1-2 sentences — problem or curiosity]
[Body: Short paragraphs, max 3 sentences each]
- Line 1: Problem/context
- Line 2-3: Solution/value
- Line 4-5: Proof/specifics
[CTA: Single, clear button]
"Get [specific thing] →"
[P.S.: Second most-read element — restate offer or add urgency]
Plain Text Best Practices
- Use plain text for personal/conversational emails
- HTML for promotional/newsletter-style
- Include plain text version of all HTML emails
Automation Triggers
Behavioral Triggers
| Trigger | Delay | |
|---|---|---|
| Sign up | Immediate | Welcome |
| First login | +1 day | Getting started |
| Feature activated | Immediate | Tips for feature |
| Inactive 7 days | +7 days | Check-in |
| Abandoned cart | +1 hour | Cart reminder |
| Purchase | Immediate | Receipt + onboarding |
| Trial expires -3 days | -72h | Upgrade nudge |
| Trial expired | Day 0 | Final offer |
Compliance Checklist
- Unsubscribe link in every email (CAN-SPAM, CASL, GDPR)
- Physical mailing address in footer
- Clear sender identification
- Honor unsubscribes within 10 days (CAN-SPAM) / immediately (GDPR)
- Do not use deceptive subject lines
- GDPR: lawful basis documented (consent or legitimate interest)
- CASL: explicit/implied consent recorded with timestamp
What ships with it
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