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Overview

Email Preflight checks your email on actual devices before you send. No more broken links, rendering issues, or compliance problems reaching subscribers.

Real Device Testing

Preview on 30+ actual email clients - not simulators

Automated Checks

Links, grammar, compliance, and deliverability

Fix with AI

One-click AI fix for all detected issues

Send with Confidence

Catch problems before subscribers see them

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What Gets Checked

Preflight runs 4 comprehensive checks:

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1. Email Client Compatibility

Tests your email on real devices:
  • Gmail (Desktop, iOS, Android)
  • Outlook (Windows, Mac, Web)
  • Apple Mail (macOS, iOS)
  • Yahoo Mail
  • 30+ more email clients
Catches:
  • Images not loading
  • Broken layouts
  • Missing fonts
  • CTA buttons not visible
  • Dark mode rendering issues
Checks every link in your email:
  • URL accessibility
  • Response time
  • HTTP status codes
  • Broken/unreachable links
Results show:
  • Working links count
  • Broken links with specific errors
  • Response time for each link

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3. Grammar & Content Quality

Analyzes your email content:
  • Spelling errors with suggestions
  • Grammar issues
  • Brand voice consistency
  • Image alt text (accessibility)
  • Professional quality checks
Email best practices:
  • Physical address present
  • Unsubscribe link included
  • Sender identification clear
  • CAN-SPAM compliance

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4. Spam & Deliverability

Predicts inbox placement:
  • Deliverability score (0-100%)
  • Inbox category prediction (Inbox, Promotions, Spam)
  • Spam trigger word detection
  • Content recommendations
Compliance checks:
  • ✅ Unsubscribe link
  • ✅ Physical mailing address
  • ✅ Sender identification
  • ✅ CAN-SPAM requirements

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How to Use Preflight

1

Create Your Email

Generate or design your email in Migma
2

Click Export/Send

When ready to export or send, preflight automatically runs
3

Review Results

See check results for all 4 areas:
  • ✅ Green = Passed
  • ⚠️ Yellow = Warnings
  • ❌ Red = Issues found
Click any check to see detailed breakdown
4

Fix Issues (Optional)

Option 1: Fix with AI
  • Click “Fix All Issues with AI”
  • Migma generates prompt with all detected issues
  • AI automatically fixes compatibility, links, grammar, compliance
Option 2: Manual Review
  • Click each check to see details
  • Fix issues in visual editor
  • Run preflight again
5

Export/Send

When satisfied, proceed with export or send

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Detailed Results View

Click any check to see full details: Email Client Compatibility:
  • Exact clients with issues
  • Specific error messages
  • Rendering previews
  • Recommended fixes
Link Validation:
  • Each link tested
  • HTTP status codes
  • Response times
  • Error descriptions
Grammar & Content:
  • Spelling errors with context
  • Suggested corrections
  • Best practice recommendations
  • Accessibility improvements
Spam & Deliverability:
  • Overall deliverability score
  • Inbox placement prediction
  • Confidence percentage
  • Compliance checklist
  • Improvement recommendations

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Fix with AI

One-click automated fix for all issues. When you click “Fix All Issues with AI”, Migma:
  1. Analyzes all detected issues:
    • Compatibility problems
    • Broken links
    • Spelling/grammar errors
    • Missing compliance elements
    • Deliverability issues
  2. Generates comprehensive fix prompt:
    • Lists every issue found
    • Specifies exact code changes needed
    • Maintains your design and branding
    • Preserves visual layout
  3. AI fixes your email:
    • Updates React Email components
    • Corrects spelling/grammar
    • Fixes broken links
    • Adds missing compliance elements
    • Optimizes for deliverability
  4. Ready to send:
    • All issues resolved
    • Maintains your brand
    • Email still looks great

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What Preflight Catches

Broken layouts across email clients:
  • Images not loading properly
  • Text overlapping or misaligned
  • Buttons appearing incorrectly
  • Fonts falling back to defaults
  • Spacing issues (margins, padding)
  • Dark mode rendering problems
Grammar and spelling issues:
  • Typos and misspellings
  • Grammar errors
  • Missing punctuation
  • Inconsistent capitalization
  • Brand voice mismatches
  • Missing alt text for images
Legal and regulatory issues:
  • Missing unsubscribe link
  • No physical mailing address
  • Unclear sender identification
  • CAN-SPAM violations
  • GDPR compliance gaps
Factors hurting inbox placement:
  • Spam trigger words
  • Poor text-to-image ratio
  • Too many links
  • Suspicious sender patterns
  • Low-quality content signals
  • Missing authentication (SPF/DKIM)

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Email Clients Tested

Desktop clients:
  • Gmail (Web, Desktop)
  • Outlook 2007-2021
  • Outlook for Mac
  • Apple Mail (macOS)
  • Thunderbird
  • Windows Mail
  • AOL Mail
Mobile clients:
  • Gmail (iOS, Android)
  • Outlook (iOS, Android)
  • Apple Mail (iOS, iPad)
  • Yahoo Mail (iOS, Android)
  • Samsung Email
  • Gmail Go
Webmail:
  • Gmail
  • Outlook.com
  • Yahoo Mail
  • AOL Mail
  • ProtonMail
Total: 30+ email clients and platforms

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Best Practices

Always run preflight before sending campaigns - Catch issues before subscribers see them
Fix compliance issues immediately - Unsubscribe links and physical addresses are legally required
Review link validation carefully - Broken links hurt credibility and conversions
Use “Fix with AI” for efficiency - Automated fixes save time while maintaining quality
Check deliverability score - Aim for 80%+ to ensure inbox placement
Test after making changes - Run preflight again after manual edits

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Deliverability Scoring

How scores are calculated:
ScorePlacementWhat It Means
90-100%InboxExcellent - Will reach primary inbox
80-89%Inbox/PromotionsGood - Should reach inbox or promotions tab
60-79%PromotionsFair - Likely promotions tab, some spam risk
Below 60%SpamPoor - High risk of spam folder
Factors affecting score:
  • Spam trigger words in content
  • Link-to-text ratio
  • Image-to-text ratio
  • Sender reputation
  • Authentication setup (SPF, DKIM, DMARC)
  • Previous engagement rates
  • Complaint rates

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Compliance Checklist

CAN-SPAM Act requirements:
Physical mailing address - Must be your real business address
Unsubscribe link - One-click unsubscribe option
Sender identification - Clear “From” name and email
Accurate subject line - Subject must match email content
Commercial disclosure - Mark promotional emails clearly
Preflight automatically checks all requirements and warns you of violations.

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Troubleshooting

If preflight doesn’t start:
  • Ensure email has content (not blank)
  • Check internet connection
  • Try refreshing the page
  • Clear browser cache
If you disagree with results:
  • Review detailed breakdown
  • Some “issues” may be intentional design choices
  • You can always “Export Anyway” to proceed
  • Warnings (yellow) are suggestions, not blockers
If AI fix fails:
  • Check that you have AI generations remaining
  • Ensure React Email template is editable
  • Try fixing issues manually in visual editor
  • Some issues may require manual review
If checks take too long:
  • Large images slow down analysis
  • Many links increase check time
  • Complex layouts take longer to validate
  • Wait 30-60 seconds before timing out

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Preflight vs Manual Testing

AspectEmail PreflightManual Testing
Time30-60 secondsHours to days
Devices30+ email clients3-5 at most
Link checksAll links automaticallyManual clicking
SpellingAutomated detectionManual proofreading
ComplianceAutomatic verificationLegal review needed
CostIncluded in MigmaDevice purchases, time

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When to Use Preflight

Always use for:
  • 📧 Major email campaigns
  • 🛍️ Product launches
  • 💰 Sales and promotions
  • 📰 Newsletters
  • 📅 Event invitations
  • 🔔 Important announcements
Optional for:
  • Internal team emails
  • Test sends
  • Quick updates
  • One-off messages
Best practice: Run preflight on every email before sending to external audiences.

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Need Help?

Visual Editor

Edit emails manually

Export Options

Export after preflight

Sending Emails

Send after checks pass

Email Best Practices

Improve deliverability