Email Review Sub-Skill

Purpose

Reviews email content before sending and provides a comprehensive quality score (0-100) across 5 weighted dimensions. Identifies critical issues, suggests improvements, and provides a rewritten version for low-scoring emails.

When to Activate

• User asks to "review this email"
• User provides email content (subject + body) for feedback
• User requests email quality check or score
• User wants to validate email before sending
• User provides Gmail draft ID for review
• User asks about email deliverability or spam risk

Input Formats

Accept email content in any of these formats:

1. Pasted text - Subject line + body in conversation
2. File path - Path to HTML email file
3. Gmail draft ID - Fetch via gmail_get_draft MCP tool
4. Raw HTML - HTML email source code

Scoring Framework

Overall Score Calculation

Total score = weighted sum of 5 categories:

1. Subject Line Scoring (25% weight)

Base Score: 0-100, then weighted at 25%

Length Check (0-25 points)

• Optimal: 6-10 words OR 30-50 characters = 25 points
• Acceptable: 5 or 11 words = 20 points
• Marginal: 4 or 12 words = 10 points
• Poor: <4 or >12 words = 0 points

Spam Trigger Detection (-5 points each)

Penalize for each occurrence:

• ALL CAPS words
• Multiple exclamation marks (!!!)
• Phrases: "FREE", "Act Now", "Limited Time", "Guaranteed", "Winner", "Click Here", "Buy Now", "Order Now"
• Excessive punctuation ($$$, ???)

Power Words (+5 points each, max +15)

Bonus for strategic use of:

• "New", "Exclusive", "Proven", "Secret", "Discover"
• "Ultimate", "Essential", "Complete", "Breakthrough"
• Industry-specific power words

Personalization (+10 points)

• Contains merge tags like {{first_name}} or {{company}}
• Behavioral personalization indicators

Emoji Usage (+5 or -5)

• 1 emoji = +5 points (increases open rates)
• 2+ emojis = -5 points (reduces professionalism)
• No emoji = 0 points (neutral)

2. Copy Quality Scoring (25% weight)

Base Score: 0-100, then weighted at 25%

Word Count (0-20 points)

• 150-300 words = 20 points (optimal)
• 100-149 or 301-400 = 15 points
• 50-99 or 401-500 = 10 points
• <50 or >500 = 0 points

CTA Count (0-25 points)

• 1 primary CTA = 25 points (best conversion)
• 2 CTAs = 15 points (acceptable)
• 3+ CTAs = 5 points (diluted focus)
• 0 CTAs = 0 points (no action path)

CTA Clarity (0-15 points)

Score based on:

• 15 points: Action verb + benefit ("Get My Free Guide", "Start Your Trial")
• 10 points: Generic action ("Learn More", "Download")
• 5 points: Vague ("Submit", "Click Here")
• 0 points: No CTA or unclear

Framework Structure (0-15 points)

Check if email follows proven framework:

• PAS (Problem-Agitate-Solution): 15 points
• AIDA (Attention-Interest-Desire-Action): 15 points
• BAB (Before-After-Bridge): 15 points
• FAB (Features-Advantages-Benefits): 15 points
• 4Ps (Picture-Promise-Proof-Push): 15 points
• No clear structure: 0 points

Readability (0-15 points)

• Short paragraphs (2-3 lines max): +5
• Bullet points or numbered lists: +5
• Scannable with subheadings: +5
• No walls of text: +5
• Deduct -5 for each readability issue

Personalization Beyond Name (0-10 points)

• Behavioral triggers (past purchase, browsing): +5
• Location/timezone awareness: +3
• Industry/role customization: +2

3. Technical/HTML Scoring (20% weight)

Base Score: 100, deduct points for violations

Total Size (-20 if fail)

• Must be under 102 KB (Gmail clips emails over this)
• Check HTML + embedded images (if data URIs)

Text-to-Image Ratio (-15 if fail)

• Minimum 60% text / 40% images
• Image-heavy emails trigger spam filters

Responsive Design (-10 if fail)

Check for:

• Viewport meta tag: <meta name="viewport" content="width=device-width">
• Media queries for mobile breakpoints
• Fluid tables or container widths

Dark Mode Support (-5 if fail)

Check for:

• <meta name="color-scheme" content="light dark">
• CSS with @media (prefers-color-scheme: dark)
• Dark mode color overrides

Alt Text on Images (-5 per missing)

• All <img> tags must have alt attribute
• Alt text should be descriptive, not just filename

Table-Based Layout (-5 if fail)

• Email should use <table> for layout (HTML email best practice)
• Deduct if using CSS Grid/Flexbox (poor email client support)

Font Safety (-5 if fail)

• Must use web-safe fonts with fallbacks
• Example: font-family: Arial, Helvetica, sans-serif;
• Avoid custom web fonts without fallbacks

CTA Button Size (-5 if fail)

• Minimum 44x44 pixels (mobile touch target)
• Check all <a> styled as buttons

Plain-Text Version (-10 if fail)

• Must have plain-text MIME part OR
• Text-only fallback within HTML

Preheader Text (-5 if missing)

• 30-80 character preview text
• Located immediately after <body> tag
• Often hidden with CSS for HTML view

4. Deliverability Signals (15% weight)

Base Score: 100, deduct points for red flags

Spam Word Density (-5 per word)

Count occurrences of spam triggers in body:

• "Free", "Winner", "Guarantee", "Risk-free", "Act now"
• "Cash", "Bonus", "Extra income", "Work from home"
• "Unsecured credit", "Viagra", "Pharmacy"

Link Count (warn at 5+)

• 0-3 links = 0 penalty
• 4-5 links = -5 points (warning threshold)
• 6+ links = -15 points (spam signal)

Image-Only Email (-20 if fail)

• Emails with only images and no text are spam signals
• Must have substantive text content

Unsubscribe Link (-25 if missing)

• Required for marketing emails
• Must be clearly visible and functional
• Check for <a> with "unsubscribe" keyword

Sender Name (-10 if generic)

• Deduct for: "info@", "noreply@", "admin@", "support@"
• Personal or company name preferred

Link Shorteners (-10 if detected)

• Penalize use of: bit.ly, tinyurl, goo.gl, ow.ly
• Spam filters distrust shortened URLs

5. Compliance Scoring (15% weight)

Base Score: 100, deduct points for violations

Physical Address (-20 if missing)

• CAN-SPAM requires postal address
• Check footer for street address or P.O. Box

Unsubscribe Mechanism (-25 if missing)

• Must have working unsubscribe link
• Should process within 10 business days (CAN-SPAM)

Honest Subject Line (-15 if misleading)

• Subject must accurately reflect email content
• No deceptive "Re:" or "Fwd:" if not a reply

RFC 8058 Headers (-10 if missing for bulk)

For bulk/marketing emails, check for:

List-Unsubscribe: <mailto:unsub@example.com>
List-Unsubscribe-Post: List-Unsubscribe=One-Click

Sender Identification (-10 if missing)

• Must clearly state who is sending the email
• Check for "From" name and footer company info

Score Interpretation

Output Format

Structure the review report as:

1. Header: ## Email Quality Review with overall score, rating, status
2. Score table: 5 categories with raw score, weight, and weighted score
3. Issues Found: Grouped by severity (Critical/High/Medium/Low) with specific fixes
4. Detailed Breakdown: Per-category analysis (subject length/triggers/power words, word count/CTA/framework, HTML size/responsive/dark mode, spam words/links, address/unsubscribe/RFC 8058)
5. Improved Version (if score < 75): Rewritten subject line, copy fix recommendations, HTML fixes

Use status badges: ✅ Ready to send (90+), ⚠️ Review suggested (75-89), ⚠️ Fix before sending (60-74), ❌ Needs rework (40-59), ❌ DO NOT SEND (0-39).

Workflow

Step 1: Intake

Identify input format and extract:

• Subject line
• Body copy (text or HTML)
• HTML source (if applicable)

Step 2: Run Analysis Scripts (if available)

Check for and execute:

# Subject line scoring
python scripts/score_subject_line.py --subject "[subject]"

# HTML email analysis
python scripts/analyze_email_html.py --file [path]

Step 3: Manual Scoring

For each category:

1. Start with base score
2. Apply positive adjustments
3. Apply penalties
4. Calculate weighted score

Step 4: Reference Checks

Consult knowledge files for edge cases:

• references/technical-standards.md - HTML/CSS email rules
• references/compliance.md - CAN-SPAM, GDPR, CASL requirements
• references/deliverability-rules.md - Deliverability scoring and spam signal reference

Step 5: Generate Report

Format output per template above, ensuring:

• Clear categorization of issues by severity
• Actionable fix recommendations
• Improved version if score < 75

Step 6: User Confirmation

Ask user if they want to:

• Apply suggested improvements
• Re-review after manual edits
• Send as-is (if score >= 75)

Quality Gates

Hard Rules (Automatic Failure)

These issues result in "DO NOT SEND" status regardless of total score:

1. Missing unsubscribe link (for marketing emails)
2. Missing physical address (CAN-SPAM violation)
3. Email size > 102 KB (Gmail will clip)
4. Image-only email (no text content)
5. Deceptive subject line (FTC violation)

Edge Cases

Gmail Drafts

If user provides draft ID:

1. Use gmail_get_draft MCP tool to fetch
2. Extract subject from payload.headers
3. Extract HTML body from payload.parts (mimeType = text/html)
4. Proceed with normal review

Plain-Text Emails

If email has no HTML:

1. Skip technical/HTML scoring (default to 80/100)
2. Focus on copy quality, subject line, compliance
3. Adjust weighting: Subject 30%, Copy 35%, Deliverability 20%, Compliance 15%

Non-English Emails

1. Note language in report
2. Skip spam word detection (English-specific)
3. Focus on structural/technical issues
4. Provide caveats about readability scoring

Transactional Emails

If email is transactional (receipts, confirmations):

1. Relax compliance rules (unsubscribe not required)
2. Focus on technical delivery and clarity
3. Note in report: "Transactional email - relaxed marketing rules"

Tools Integration

Available Scripts

Run these scripts from the scripts/ directory:

score_subject_line.py

• Input: python scripts/score_subject_line.py --subject "Subject line text" --json
• Output: JSON with length, spam triggers, power words, score
• Use: Auto-score subject line component

analyze_email_html.py

• Input: python scripts/analyze_email_html.py --file path/to/email.html --json
• Output: JSON with size, responsiveness, alt text, preheader, issues
• Use: Auto-score technical/HTML component

MCP Tools

gmail_get_draft

• Fetch draft email from Gmail by ID
• Extract subject and HTML body

gmail_send_message

• Send reviewed email (after user approval)

Examples

High-scoring email (92/100): Subject "New guide: 5 proven SEO tactics for 2026" -- 8 words, power word, no spam triggers, 280 words, 1 CTA, responsive HTML, all compliance elements present. Status: Ready to send.

Low-scoring email (23/100): Subject "FREE MONEY!!! ACT NOW GUARANTEED WINNER!!!" -- all caps, 4 spam triggers, 50 words, 5 CTAs, missing unsubscribe and address. Status: DO NOT SEND (CAN-SPAM violations).

Notes

• Always run available scripts before manual scoring
• Reference knowledge files for edge cases
• Provide specific, actionable recommendations
• Never approve emails with compliance violations
• Weight user industry context (B2B vs B2C vs transactional)
• Update scoring criteria based on evolving best practices