email-sequence（电子邮件序列）

Email Sequence Design

Category: Marketing Tags: email sequences, drip campaigns, nurture flows, onboarding emails, lifecycle marketing, automation

Overview

Email Sequence Design creates complete, ready-to-implement email automation flows. Every output includes subject lines, preview text, full body copy, CTAs, send timing, and exit conditions. The goal is sequences that nurture relationships and drive specific conversion actions -- not just "stay top of mind" email noise.

This skill writes the sequences. For email HTML templates and rendering infrastructure, use email-template-builder. For tracking email performance, use analytics-tracking.

Sequence Types

Design Process

Step 1: Define Sequence Architecture

Before writing any email, define the architecture:

Sequence Name:     [Name]
Trigger:           [What starts the sequence]
Primary Goal:      [Single conversion action]
Secondary Goals:   [Relationship building, data collection]
Length:            [Number of emails]
Duration:          [Total time span]
Exit Conditions:   [When they leave the sequence]
Suppression:       [Other sequences to suppress while active]

Step 2: Map the Emotional Journey

Each email serves a purpose in a progression:

Step 3: Write Each Email

For every email in the sequence, deliver:

Email [#]: [Name/Purpose]
Send:     [Timing from trigger or previous email]
Segment:  [Conditions -- who receives this variant]

Subject:  [Subject line - under 50 characters]
Preview:  [Preview text - 80-120 characters, complements subject]

Body:
[Complete copy -- not an outline, not bullets, the actual words]

CTA:      [Button text] → [Destination URL]
P.S.:     [Optional -- works for urgency or human touch]

Step 4: Define Branching Logic

Not everyone follows the same path. Define branches:

After Email 2:
  IF user activated core feature → Skip to Email 4 (post-activation)
  IF user has not logged in → Send Email 2B (re-engagement variant)
  IF user unsubscribed → Exit sequence

After Email 4:
  IF user converted → Exit sequence, enter post-purchase sequence
  IF user visited pricing 2+ times → Send Email 4B (pricing objection handler)
  ELSE → Continue to Email 5

Sequence Blueprints

Blueprint: SaaS Welcome/Onboarding (7 emails, 14 days)

Exit conditions: User converts to paid at any point, user unsubscribes, user explicitly requests removal.

Branching:

• After Email 2: If user completed core action, skip Email 3, go to Email 4
• After Email 4: If user has not logged in for 5+ days, switch to re-engagement variant
• After Email 6: If user visited pricing page, send pricing-focused Email 7 variant

Blueprint: Lead Nurture (6 emails, 30 days)

Exit conditions: Books demo, starts trial, unsubscribes, or completes sequence.

Blueprint: Re-engagement (4 emails, 14 days)

Critical rule: If no engagement after Email 4, remove from active email list. Sending to unengaged contacts damages sender reputation.

Blueprint: Trial Expiration (5 emails, 7 days)

Subject Line Framework

Formulas That Work

Subject Line Rules

1. Under 50 characters (mobile truncation happens at 35-45)
2. No ALL CAPS words
3. No excessive punctuation (!!!)
4. No spam trigger words in subject: free, guarantee, limited time, act now
5. Preview text must complement, not repeat, the subject
6. A/B test subject lines on every sequence (minimum 3 variants per email)

Timing & Cadence

Optimal Send Times (B2B SaaS)

Sequence Spacing Rules

• Welcome email: Immediate (within 5 minutes of trigger)
• Onboarding emails: Every 1-3 days (maintain momentum)
• Nurture emails: Every 3-7 days (avoid fatigue)
• Re-engagement: Every 3-5 days (test urgency vs respect)
• Trial expiration: Accelerating cadence (7 days, 3 days, 1 day, 0, +3)

Metrics & Benchmarks

Expected Performance by Sequence Type

Health Indicators

Segmentation Strategy

Behavioral Segments

Personalization Tiers

Implementation Checklist

• Sequence architecture documented (trigger, goal, length, exits)
• All emails written with subject, preview, body, CTA
• Branching logic defined for key decision points
• Subject line A/B variants created (minimum 3 per email)
• UTM parameters configured for all links
• Suppression rules set (no overlapping sequences)
• Unsubscribe handling confirmed (one-click, CAN-SPAM compliant)
• Plain text version created for each email
• Send time optimized for recipient timezone
• Metrics dashboard configured (opens, clicks, conversions, unsubs)
• 30-day post-launch review scheduled

Proactive Triggers

• User mentions low trial-to-paid conversion: ask about trial expiration email sequence before recommending pricing changes
• User reports high open rates but low clicks: diagnose body copy and CTA before blaming subject lines
• User wants to "do email marketing": clarify sequence type before writing anything
• User has a product launch coming: recommend coordinating launch email sequence with in-app messaging
• User mentions list going cold: suggest re-engagement sequence before recommending acquisition spend

Related Skills

Troubleshooting

Success Criteria

• Welcome sequence open rate above 50% (benchmark: 50-70%)
• Nurture sequence click-through rate above 3% (benchmark: 3-8%)
• Trial expiration conversion rate above 10% (benchmark: 10-25%)
• Unsubscribe rate below 0.5% per email (below 0.3% for nurture)
• Every email has 3+ subject line A/B variants tested
• Branching logic covers at least 2 behavioral segments per sequence
• Sequence-level conversion rate (total conversions / initial sends) above 5%

Scope & Limitations

In Scope: Lifecycle email sequence design, copy, timing, branching logic, segmentation, and performance optimization for SaaS/B2B.

Out of Scope: Email HTML rendering (use email-template-builder), cold outreach sequences (use cold-email), marketing automation platform setup, transactional email infrastructure.

Limitations: Benchmarks are SaaS/B2B focused. Adjust thresholds for e-commerce, consumer, or other verticals.

Python Automation Tools

1. Subject Line Scorer (scripts/subject_line_scorer.py)

Scores sequence email subject lines for open-rate potential and auto-detects sequence type (welcome, trial, nurture, re-engagement).

python scripts/subject_line_scorer.py "Your trial ends tomorrow"
python scripts/subject_line_scorer.py --file subjects.txt --json

2. Sequence Mapper (scripts/sequence_mapper.py)

Generates a visual sequence map with timing, branching logic, and exit conditions from a sequence definition.

python scripts/sequence_mapper.py sequence_def.json
python scripts/sequence_mapper.py --sample --json

3. Performance Analyzer (scripts/performance_analyzer.py)

Analyzes email sequence metrics against benchmarks, identifies bottlenecks, and recommends optimizations.

python scripts/performance_analyzer.py metrics.json
python scripts/performance_analyzer.py --sample --json