Guides
How to Test Where My Klaviyo Emails Are Landing in Gmail Inboxes
Author :
MailMend Team
December 19, 2025
Most Klaviyo users assume their emails reach the Primary inbox—until they check the data. The reality? Gmail's algorithms route the majority of e-commerce marketing emails to the Promotions tab, where open rates drop significantly. For brands relying on email revenue, understanding exactly where your campaigns land is the difference between hitting targets and watching engagement decline. Mailmend offers a direct solution by moving campaigns from Promotions to Primary without changing your email content, but first, you need to know where your emails currently land.
Key Takeaways
Klaviyo's built-in Inbox Testing feature only shows visual rendering—it does NOT test whether emails land in Primary, Promotions, or Spam
Google Postmaster Tools provides free ongoing monitoring but requires 200+ emails/day to Gmail addresses before showing data
Brands using pre-send placement testing report significantly higher email-attributed revenue compared to those who don't test
Smart Sending must be disabled for testing—otherwise Klaviyo skips addresses already contacted
Klaviyo's "100% delivered" metric is misleading—"delivered" means accepted by Gmail's server, not landed in inbox
Understanding Gmail's Inbox Tabs: Primary vs. Promotions
Gmail's tabbed inbox system automatically categorizes incoming emails into Primary, Social, Promotions, Updates, and Forums. For e-commerce brands, this algorithmic sorting directly impacts whether subscribers see your campaigns.
What Are Gmail's Filtering Mechanisms?
Gmail uses machine learning to analyze multiple signals when categorizing emails:
Sender patterns: History of promotional content from your domain
Content analysis: Marketing language, promotional offers, discount codes
Link density: Number and type of links in your emails
Image-to-text ratio: Heavy image usage signals promotional content
Engagement history: How recipients interact with your emails over time
Authentication records: SPF, DKIM, and DMARC configuration
These signals combine to create what's effectively a "promotional threshold"—cross it, and Gmail routes your email to Promotions automatically.
Why Does Placement Matter for E-commerce?
The Promotions tab isn't spam, but it creates a visibility gap. Subscribers actively check their Primary inbox throughout the day. The Promotions tab? Most users batch-check it weekly—or ignore it entirely.
This placement difference compounds over time:
Lower open rates: Emails in Promotions receive significantly less attention
Reduced click-through rates: Less visibility means fewer clicks to your store
Decreased revenue per send: The same campaign generates less when buried in Promotions
Weaker sender reputation: Low engagement signals to Gmail that your emails aren't valued
For seven-to-eight-figure e-commerce brands, open rate improvements from Primary inbox placement can translate to tens of thousands in additional monthly revenue.
Manual Testing Methods for Gmail Inbox Placement
Before investing in specialized tools, you can manually verify where your Klaviyo emails land using simple test accounts.
Setting Up a Diverse Gmail Test Audience
Create a seed list of Gmail accounts that represent different scenarios:
Fresh Gmail accounts: New accounts with no history of your emails
Engaged accounts: Addresses that have opened and clicked previous campaigns
Dormant accounts: Addresses that haven't engaged in 60+ days
Different Gmail app versions: Desktop web, mobile app, and tablet
Add these test addresses to a dedicated list in Klaviyo called "Internal Testing" or "Seed List."
Analyzing Placement Across Multiple Tests
For each campaign, send to your seed list before launching to your full audience:
Send the campaign to your test list
Wait 10-15 minutes for delivery
Check each Gmail account manually
Document where the email landed: Primary, Promotions, Social, Updates, or Spam
Note any patterns: Does the same email land differently across accounts?
This manual approach reveals real-world placement but has significant limitations.
Limitations of Manual Testing
Manual testing doesn't scale:
Time-intensive: Checking multiple accounts for every campaign is impractical
Small sample size: A handful of test accounts doesn't represent your entire list
No historical tracking: You can't identify trends over time
Inconsistent methodology: Human error introduces variability
No spam scoring: You won't know why emails land where they do
For serious deliverability monitoring, automated tools are essential.
Leveraging Klaviyo's A/B Testing for Deliverability Insights
Klaviyo's native A/B testing provides indirect signals about inbox placement through performance metrics.
Structuring an A/B Test for Inbox Placement
While Klaviyo can't directly tell you which tab received your email, you can infer placement through engagement variance:
Test subject lines: Promotional language vs. conversational tone
Compare send times: Peak hours vs. off-peak delivery
Vary content structure: Image-heavy vs. text-forward designs
Segment by engagement: High-openers vs. full list performance
When one variant dramatically outperforms another, placement differences may explain the gap.
Interpreting Klaviyo's Performance Reports
Klaviyo's deliverability monitoring tracks several key metrics:
Delivery rate: Percentage of emails accepted by receiving servers
Open rate: Percentage of delivered emails opened
Click rate: Percentage of opens that generate clicks
Bounce rate: Hard and soft bounces as percentage of sends
Spam complaints: Recipients marking your email as spam
A sudden drop in open rates—without corresponding changes to your content or list—often indicates placement issues rather than content problems.
Correlating Metrics with Perceived Placement
Look for these patterns in your Klaviyo analytics:
Consistent 15-25% open rates: Likely landing in Promotions
Open rates above 35%: Stronger Primary inbox presence
Declining open rates over time: Possible reputation degradation
High click-to-open rates but low open rates: Good content, poor placement
Mailmend enables brands to conduct A/B testing within Klaviyo to measure exact performance lift from Primary inbox placement versus Promotions tab placement—removing the guesswork entirely.
Actionable Insights from Deliverability Reports
Use placement data to inform strategy:
High Spam percentage: Authentication issues or content triggers—investigate immediately
High Promotions percentage: Expected for marketing emails, but improvable
Missing percentage: Emails blocked entirely—serious deliverability problem
Inconsistent results: Test more frequently to identify patterns
Brands using monthly placement testing maintain stronger inbox placement rates compared to those who don't test regularly.
Decoding Gmail's Promotional Threshold Factors
Understanding what triggers Promotions tab placement helps you test more strategically.
Common Elements That Trigger Promotions Tab Placement
Gmail's algorithms flag these signals:
Promotional language: "Sale," "discount," "limited time," "free shipping"
Heavy HTML formatting: Complex templates with multiple columns
Image-to-text imbalance: More images than text content
Multiple CTAs: Several competing calls-to-action
Unsubscribe placement: Footer-heavy unsubscribe links signal marketing
Tracking pixels: Extensive tracking code signals automated marketing
Link density: Many links increase promotional scoring
Best Practices for Content and Design
To reduce promotional signals while testing:
Use plain text variations: Test simplified designs against standard templates
Limit images: Test with 1-2 images versus image-heavy layouts
Reduce links: Test campaigns with fewer total links
Conversational copy: Test personal, non-promotional language
Single CTA focus: Test one clear action versus multiple options
However, these content changes often conflict with proven e-commerce email practices. You shouldn't have to choose between effective marketing copy and inbox placement.
Mailmend's proprietary AI analyzes these promotional threshold factors and generates custom code that counteracts Gmail's categorization signals—without requiring any changes to your email content or copywriting.
Strategies to Improve Primary Inbox Placement in Gmail
Beyond testing, several factors influence long-term placement success.
Building Strong Sender Reputation
Your domain and IP reputation directly impact placement:
Maintain list hygiene: Remove bounced and unengaged addresses regularly
Authenticate properly: Configure SPF, DKIM, and DMARC correctly
Use a branded sending domain: Avoid default Klaviyo sending domains
Monitor spam complaints: Keep rates below 0.3% to meet Gmail's bulk sender requirements
Warm new domains gradually: Don't blast full volume immediately after setup
Encouraging Subscriber Engagement
Gmail weighs engagement heavily in placement decisions:
Segment by engagement: Send more frequently to active subscribers
Re-engage dormant contacts: Win-back campaigns for unresponsive addresses
Ask for replies: Replies signal to Gmail that your emails are wanted
Encourage allowlisting: Guide subscribers to add your address to contacts
Provide value consistently: Engaged subscribers open more emails
Technical Configurations for Better Deliverability
Ensure your technical foundation is solid:
Verify DNS records: Confirm SPF, DKIM, DMARC are properly configured
Set up Google Postmaster Tools: Essential for monitoring Gmail-specific performance
Use consistent "From" addresses: Don't rotate sending addresses unnecessarily
Monitor blacklists: Check that your domain and IPs aren't listed
These strategies improve placement over time but require weeks or months to show results. For immediate impact, algorithmic solutions provide faster outcomes.
How Mailmend Moves Your Emails to Primary Without Content Changes
For e-commerce brands that need results faster than traditional deliverability optimization allows, Mailmend offers a direct path to Primary inbox placement.
The Mailmend Approach to Inbox Placement
Mailmend operates differently from traditional deliverability tools:
Analysis phase: Mailmend sends your emails to a rotating set of test inboxes to determine current placement
AI processing: Proprietary algorithms analyze the promotional threshold factors affecting your specific Klaviyo account
Custom code generation: Account-specific code is created to counteract promotional categorization signals
Integration: The code installs via drag-and-drop into your Klaviyo templates in under 5 minutes
The result? Your existing email content, copy, and design remain unchanged—but Gmail categorizes them differently.
Proven Results from E-commerce Brands
Mailmend's case studies document measurable outcomes:
Dr. Squatch: 112% email revenue increase, 42% open rate improvement, 67% CTR increase within 24 hours
StickerYou: "Day 1 boost of 20% - 100% Increase by month 1." 64% open rate increase and 43% CTR increase
Ministry of Supply: Results within a business day. 27% open rate increase and 30% CTR increase
Larsson & Jennings: Saved their Black Friday after deliverability problems. 82% open rate increase and 51% CTR increase
Amberjack: "It Actually Worked." 54% open rate increase and 51% CTR increase
Clevr Blends: Made a big difference. 21% open rate increase and 63% CTR increase
These brands maintained their email strategies while gaining Primary inbox visibility.
Testing Mailmend's Impact with Klaviyo A/B Tests
Mailmend integrates with Klaviyo's native A/B testing to provide transparent measurement:
Split your audience: Half receives emails with Mailmend code, half without
Track within Klaviyo: Use your existing analytics dashboard
Measure exact lift: Compare open rates, click rates, and revenue attribution
Validate Day 1: Results appear immediately—no waiting for gradual improvement
For brands serious about email revenue, Mailmend offers a revenue satisfaction guarantee. Contact Mailmend to book a demo and see current placement data for your account.
Analyzing Performance Lift: Beyond Open Rates
Inbox placement testing matters because it connects directly to revenue.
Measuring Actual Revenue Impact
Don't stop at engagement metrics—track business outcomes:
Revenue per email sent: Total email revenue divided by emails delivered
Revenue per recipient: Revenue attributed to specific segments
Conversion rate by placement: Orders generated from Primary vs. Promotions
Average order value: Whether inbox placement affects purchase size
Calculating ROI from Improved Inbox Placement
To estimate potential impact:
Current email revenue: Your baseline monthly email-attributed revenue
Current open rate: Your average open rate across campaigns
Projected improvement: Open rate increase from Primary placement (typically 20-50%)
Revenue correlation: Higher opens typically drive proportional click and revenue increases
For a brand generating $50,000/month from email with 15% open rates, a 30% improvement in open rates from better placement could mean $15,000+ in additional monthly revenue.
Long-Term Benefits of Consistent Primary Tab Delivery
Sustained Primary inbox placement compounds over time:
Improved sender reputation: Higher engagement signals quality to Gmail
Better list health: Engaged subscribers stay subscribed longer
Increased customer lifetime value: More touchpoints mean stronger relationships
Competitive advantage: Your emails get seen while competitors remain buried in Promotions
Frequently Asked Questions
How does Gmail decide if an email goes to the Primary or Promotions tab?
Gmail uses machine learning to analyze multiple signals: sender patterns, promotional language, link density, image-to-text ratio, engagement history, and authentication records. These factors create a "promotional threshold"—emails crossing it route to Promotions automatically. The algorithm weighs past behavior heavily, meaning brands with promotional sending histories face stricter categorization. Proper authentication (SPF, DKIM, DMARC) is necessary but not sufficient for Primary placement.
Can I manually test my Klaviyo email placement without extra tools?
Yes, but with significant limitations. Create seed Gmail accounts representing different scenarios (fresh, engaged, dormant), send campaigns to them before your full audience, and manually check where emails land. This approach works for spot-checking but doesn't scale for regular monitoring. You won't get spam scoring, authentication analysis, or historical trend data.
What kind of performance improvements can I expect from moving emails to the Primary inbox?
Brands achieving consistent Primary inbox placement typically see open rate improvements of 20-50%, with corresponding increases in click-through rates and revenue. Mailmend clients have documented results including 112% revenue increases (Dr. Squatch), 50-60% CTR improvements, and results appearing within 24 hours of implementation. Actual impact depends on your current placement, list quality, and engagement patterns—A/B testing provides exact lift measurement for your specific audience.
Does Mailmend require me to change my email content or strategy?
No. Mailmend's approach specifically avoids content modifications. The solution works through custom code that integrates with your existing Klaviyo templates via drag-and-drop installation taking under 5 minutes. Your email copy, design, promotional offers, and sending strategy remain unchanged. This differentiates Mailmend from traditional deliverability consulting, which typically requires comprehensive content strategy overhauls, subject line restrictions, or reduced promotional messaging.
How quickly can I see results from inbox placement improvements?
With manual testing and traditional deliverability optimization, meaningful improvements typically take 2-4 weeks minimum as reputation rebuilds and Gmail's algorithms adjust to changed behavior. Domain warming for new sending infrastructure can take 4-8 weeks. Mailmend clients report results appearing within 24 hours—Ministry of Supply saw improvement within one business day, and Dr. Squatch documented impact within 24 hours of implementation. Klaviyo's A/B testing enables immediate measurement of performance differences.
