When this skill is activated, always start your first response with the 🧢 emoji.
Email Marketing
Email marketing remains one of the highest-ROI channels in digital marketing (average $36 for every $1 spent). Effective email marketing is not about sending more emails - it is about sending the right message to the right person at the right time. This skill covers campaign design, drip sequence architecture, deliverability fundamentals, segmentation models, and systematic A/B testing.
When to use this skill
Trigger this skill when the user:
- Wants to design or improve an email campaign (newsletter, promotional, announcement)
- Needs to build a drip sequence (welcome series, onboarding, nurture, re-engagement)
- Asks about email deliverability, spam scores, or inbox placement
- Wants to write or improve subject lines or preview text
- Needs to set up email automation flows and triggers
- Asks about audience segmentation strategies
- Wants to run A/B tests on email content or timing
- Needs to understand or improve open rates, CTR, or conversion rates
- Asks about responsive / mobile email design
- Wants to set up lifecycle email automation
Do NOT trigger this skill for:
- SMS or push notification marketing (different channel mechanics)
- Cold outbound sales prospecting (governed by separate compliance frameworks
like CAN-SPAM / GDPR and different deliverability rules than permission email)
Key principles
- Permission-based always - Only email people who explicitly opted in.
Purchased lists destroy sender reputation, violate GDPR/CAN-SPAM, and produce near-zero ROI. A small engaged list beats a large unengaged one every time.
- Segment before sending - A single blast to your entire list is almost never
the right move. Even basic segmentation (active vs. dormant, product interest, lifecycle stage) meaningfully improves relevance and reduces unsubscribes.
- Subject line is 80% of the battle - If the email is not opened it does not
exist. Spend disproportionate effort on subject lines and preview text. Test them constantly.
- Mobile-first design - More than 60% of emails are opened on mobile.
Single-column layouts, minimum 16px body text, large tap targets (44px+), and short subject lines (under 40 characters) are non-negotiable defaults.
- Test everything - Intuition about what works in email is frequently wrong.
Run structured A/B tests on subject lines, CTAs, send times, and content format. Let data override opinion.
Core concepts
Email types
| Type | Purpose | Examples | |---|---|---| | Transactional | Triggered by user action, 1:1, expected | Order confirmations, password resets, receipts | | Marketing | Promotional, sent to segments, opt-in | Newsletters, sales campaigns, product announcements | | Lifecycle | Behavior-triggered, relationship-building | Welcome series, onboarding, re-engagement, win-back |
Transactional emails have the highest open rates (60-80%) and must not be used for marketing purposes - doing so violates trust and often CAN-SPAM.
Deliverability factors
Deliverability is whether your email reaches the inbox (not just whether it was "sent"). Key factors:
Sender reputation - ISPs score your sending domain and IP based on engagement, spam complaints, and bounce rates. Reputation takes months to build and days to destroy. Keep complaint rates below 0.1% and hard bounce rates below 2%.
Authentication - Three DNS records that ISPs use to verify you are who you say you are:
- SPF (Sender Policy Framework) - lists authorized sending IPs for your domain
- DKIM (DomainKeys Identified Mail) - cryptographically signs each email
- DMARC (Domain-based Message Authentication) - policy for handling failures;
start with p=none (monitor), progress to p=quarantine, then p=reject
List hygiene - Remove hard bounces immediately. Suppress unsubscribes immediately. Run re-engagement campaigns before sunsetting inactive subscribers.
Engagement signals - Opens, clicks, and replies positively signal to ISPs. Low engagement from a segment drags down your domain reputation. Suppress chronically unengaged subscribers.
Segmentation models
| Model | Segments | When to use | |---|---|---| | Engagement-based | Active, At-risk, Dormant | Deliverability management, re-engagement | | Lifecycle stage | Prospect, New customer, Loyal, Lapsed | Onboarding and retention flows | | RFM | Recency, Frequency, Monetary | E-commerce, purchase-based personalization | | Behavioral | Pages visited, features used, content downloaded | SaaS onboarding, content marketing | | Demographic | Role, company size, industry | B2B campaigns, product-specific content |
Key metrics
| Metric | Definition | Healthy benchmark | |---|---|---| | Open rate | Unique opens / emails delivered | 20-30% (B2C), 25-35% (B2B) | | Click-through rate (CTR) | Unique clicks / emails delivered | 2-5% | | Click-to-open rate (CTOR) | Clicks / opens - measures content quality | 10-20% | | Conversion rate | Desired actions / emails delivered | Varies by goal | | Unsubscribe rate | Unsubs / emails delivered | Keep below 0.2% | | Spam complaint rate | Complaints / emails delivered | Keep below 0.1% | | Hard bounce rate | Permanent delivery failures / sent | Keep below 2% |
Note: Apple Mail Privacy Protection (MPP) inflates open rates since iOS 15. Use CTOR and conversion rate as more reliable engagement signals.
Common tasks
Design a drip sequence
A drip sequence is a series of pre-written emails sent on a schedule or triggered by behavior. Plan before writing:
- Define the goal - What behavior should the sequence drive? (activation,
purchase, re-engagement, education)
- Map the journey - What does the subscriber need to know / feel / do at each
step to move toward the goal?
- Set timing - Welcome: immediate. Onboarding: days 0, 2, 5, 10. Nurture:
weekly or bi-weekly. Re-engagement: day 30, 45, 60 of inactivity.
- Write each email as a unit - Each email should have one goal, one CTA.
Ready-to-use templates for welcome, onboarding, and nurture sequences: see references/drip-templates.md.
Welcome series structure (3 emails):
- Email 1 (immediate): Deliver the promised value, set expectations, introduce brand
- Email 2 (day 2-3): Share your best piece of content or biggest benefit
- Email 3 (day 5-7): Social proof + primary CTA
Onboarding series structure (5 emails):
- Email 1 (day 0): Account created - first action to take (one thing only)
- Email 2 (day 2): How to accomplish the primary use case
- Email 3 (day 5): Advanced tip or power feature
- Email 4 (day 10): Success story from a similar user
- Email 5 (day 14): Check-in - did they reach activation? If not, offer help.
Nurture series structure:
- Value-first ratio: 3 educational emails for every 1 promotional email
- Frequency: 1-2 per week maximum; let engagement guide cadence
- Personalize based on content topic interest or product category
Write high-converting subject lines
Subject lines determine whether the email gets opened. Apply these formulas:
| Formula | Template | Example | |---|---|---| | Curiosity gap | "[Intriguing claim] (here's why)" | "We almost didn't send this email" | | Numbered list | "[N] ways to [achieve outcome]" | "5 ways to cut your churn in half" | | Direct benefit | "[Outcome] in [timeframe/way]" | "Double your open rates this week" | | Question | "[Question the reader is asking themselves]" | "Still struggling with deliverability?" | | Social proof | "How [person/company] achieved [result]" | "How Notion grew to 20M users via email" | | Urgency/scarcity | "[Benefit] - [deadline]" | "Your free trial ends tomorrow" | | Personalization | "[First name], [relevant message]" | "Sarah, your report is ready" |
Subject line rules:
- Keep under 50 characters (under 30 for mobile previews)
- Avoid ALL CAPS, exces