30 Global Email Deliverability Statistics Every E-commerce Brand Needs to Know

Data-driven insights revealing why inbox placement is declining across major ISPs and how algorithmic solutions are transforming e-commerce email revenue

Email remains the highest-ROI channel for e-commerce brands, yet nearly 17% of marketing emails never reach the intended recipient's inbox. For seven-to-eight-figure DTC brands, this translates to millions in lost revenue annually. The challenge intensifies when emails land in Gmail's Promotions tab rather than the Primary inbox—a problem Mailmend solves through proprietary algorithmic technology that moves campaigns to the Primary inbox without requiring content changes.

Key Takeaways

• Global email volume is surging – Daily email traffic will grow from 361.6 billion in 2024 to 424.2 billion by 2028, intensifying competition for inbox placement

• Deliverability rates are declining sharply – Office365 inbox placement dropped 26.73% from Q1 2024 to Q1 2025, with Gmail down 5.02%

• The Promotions tab kills visibility – Gmail achieves 95.54% deliverability, but only 57.8% lands in the Primary inbox while 37.74% goes to Promotions

• High-volume senders face the steepest declines – Brands sending 1M+ emails monthly experienced a 22.35% drop in inbox placement

• Regional differences create opportunities – Europe maintains 91% inbox placement versus Asia-Pacific's 78%

• ESP performance varies dramatically – Klaviyo inbox placement fell 13.24% year-over-year, making supplemental solutions essential

The Promotions Tab Problem: Why E-commerce Emails Land There

1. Gmail delivers 95.54% of emails but splits placement between tabs

While Gmail achieves a 95.54% average deliverability rate, the reality for e-commerce brands is more nuanced. Only 57.8% of delivered emails arrive in the Primary inbox, while 37.74% get filtered to the Promotions tab. This tab categorization dramatically reduces visibility and engagement for marketing campaigns.

2. The "Big Four" ISPs process 87% of all emails

Google, Microsoft, Yahoo, and AOL make up 87% of relative market share, processing 7 out of 8 emails globally. This concentration means Gmail's categorization algorithms disproportionately impact e-commerce email performance. Understanding how these ISPs filter promotional content is essential for revenue optimization.

3. Gmail inbox placement dropped 5.02% year-over-year

Between Q1 2024 and Q1 2025, Gmail inbox placement decreased from 58.72% to 53.70%—a 5.02% decline. This tightening of inbox standards reflects Gmail's increasingly sophisticated filtering of promotional content. E-commerce brands relying solely on traditional deliverability tactics face mounting challenges.

4. Google Workspace placement declined 10.49%

For brands targeting B2B customers and professional audiences, Google Workspace inbox placement fell from 63.85% to 53.36% in the same period. This steeper decline indicates that even legitimate business communications face stricter scrutiny from Google's algorithms.

Low Open Rates and CTRs: The Financial Cost of Poor Deliverability

5. 16.9% of all marketing emails never reach the inbox

The average email deliverability rate across 15 major ESPs sits at just 83.1%, meaning nearly 1 in 6 marketing emails fails to reach recipients. For an e-commerce brand with 100,000 subscribers, this represents 16,900 missed opportunities per campaign. The revenue implications compound with every send.

6. 10.5% of emails land in spam folders

Beyond the Promotions tab challenge, 10.5% of emails end up in recipients' spam folders where they're essentially invisible. Combined with the 6.4% that go missing entirely, e-commerce brands face significant message loss before engagement even becomes possible.

7. Welcome emails achieve 83.63% open rates—when they reach the inbox

GetResponse data shows welcome emails generate 83.63% open rates and 16.6% click-through rates—the highest of any automated email type. However, these industry-leading metrics only materialize when messages reach the Primary inbox. Brands seeing lower welcome email performance should examine placement rather than content.

8. Average open rates improved to 39.64% in 2023

Industry-wide, average email open rates increased from 26.8% in 2022 to 39.64% in 2023, while click-through rates rose from 1.89% to 3.2%. These improvements demonstrate that when emails reach recipients effectively, engagement follows. The gap between top performers and average brands often comes down to inbox placement rather than creative quality.

9. Click-to-open rates improved to 2.99% in Q4 2024

Zeta Global's benchmark report shows click-to-open rates improved from 2.21% to 2.99% year-over-year. This metric measures engagement quality among those who actually open emails, suggesting recipients are more responsive when they encounter relevant messages in their Primary inbox.

Traditional Deliverability Solutions vs. Algorithmic Fixes

10. 61% of email marketers believe deliverability is getting harder

A Validity survey reveals that 61% of email marketers think deliverability has become more challenging. Traditional approaches—content modification, domain warming, IP reputation management—require weeks or months to show results. Meanwhile, revenue losses accumulate daily.

11. Mailgun inbox placement dropped 27.75%

Among traditional email infrastructure providers, Mailgun experienced the steepest decline, with inbox placement falling from 53.80% to 26.05% between Q1 2024 and Q1 2025. This 27.75% drop illustrates how technical infrastructure alone cannot guarantee inbox placement in today's environment.

12. Mailchimp placement fell 19.63%

Even established ESPs face mounting challenges. Mailchimp's inbox placement dropped from 51.93% to 32.30% year-over-year—a 19.63% decline that affects millions of e-commerce brands relying on the platform for their email marketing.

13. Amazon SES decreased 14.60%

Amazon SES, often chosen for its scalability and cost efficiency, saw inbox placement fall from 54.90% to 40.30%. Even enterprise-grade infrastructure cannot overcome algorithmic categorization without specialized intervention.

The Klaviyo Advantage: Tailored Deliverability for E-commerce

14. Klaviyo inbox placement fell 13.24% year-over-year

Despite being the dominant ESP for e-commerce, Klaviyo's inbox placement dropped from 56.90% to 43.66% between Q1 2024 and Q1 2025. This decline underscores why Klaviyo users increasingly seek supplemental solutions to maintain revenue performance.

For brands using Klaviyo, Mailmend's case studies demonstrate how algorithmic inbox placement technology can reverse these trends—Dr. Squatch achieved 112% email revenue increase with 42% open rate improvement and 67% CTR increase within 24 hours of implementation.

15. Retail sector maintains 99.6% delivery rates

The retail industry achieves 99.6% delivery rates in Q4 2024, demonstrating that emails reach mail servers successfully. The challenge isn't delivery—it's placement. Emails can be "delivered" to the Promotions tab or spam folder while technically counting as successful sends.

16. Unique open rates averaged 40.7% across all industries

Zeta Global reports 40.7% unique open rates across all industries in Q4 2024, down from 46.0% year-over-year. This decline, despite maintained delivery rates, suggests inbox placement rather than content quality drives engagement performance.

Immediate Impact: Day 1 Results in Email Deliverability

17. High-volume senders experienced 22.35% inbox placement decline

Brands sending over 1 million emails monthly faced the steepest decline, with inbox placement falling from 49.98% to 27.63%—a 22.35% drop. Aggressive email strategies, while valuable for revenue, trigger stricter algorithmic filtering from major ISPs.

18. Mid-volume senders (200K-1M) actually improved 11.19%

Interestingly, senders in the 200K-1M monthly email range saw inbox placement increase from 49.77% to 60.96%. This suggests that moderate sending volumes combined with proper optimization can achieve strong results—a sweet spot many seven-figure e-commerce brands occupy.

19. Small senders (1-10K) saw minimal change at +0.8%

The smallest senders experienced nearly flat performance, moving from 49.40% to 50.20% inbox placement. Lower volume naturally attracts less algorithmic scrutiny, but these brands also generate less email revenue overall.

20. Triggered emails achieve 45.38% open rates

Automated, behavior-triggered emails achieve 45.38% average open rates and 5.02% click-through rates—significantly outperforming batch campaigns. These messages benefit from relevance and timing, but their performance ceiling depends entirely on inbox placement.

Regional Deliverability: Global Performance Variations

21. Europe leads globally with 91% inbox placement

European markets achieve approximately 91% inbox placement—the highest globally. GDPR compliance has paradoxically improved deliverability by enforcing cleaner lists and explicit consent, creating healthier sender-recipient relationships.

22. Asia-Pacific struggles at 78% average placement

The Asia-Pacific region faces the lowest average inbox placement at approximately 78%. E-commerce brands expanding into APAC markets must account for these regional variations in their revenue projections and campaign strategies.

23. United Kingdom achieved 98.8% deliverability

Among individual countries, the UK leads with 98.8% deliverability, followed by Germany at 97.8%. These strong performances reflect mature email ecosystems with established sender authentication standards.

24. India lags at 69-70% inbox placement

Indian market inbox placement sits at approximately 69-70%—among the lowest globally. Brands targeting Indian consumers face significant deliverability headwinds that require specialized attention.

25. Canada outperforms the US at 90% vs. 85%

North American deliverability shows notable variation, with Canada achieving approximately 90% inbox placement versus 85% in the United States. Canadian anti-spam legislation (CASL) may contribute to healthier list practices and improved deliverability.

Beyond the Inbox: The Future of Email Deliverability

26. Global email users will reach 4.97 billion by 2028

The email audience continues expanding, with users projected to grow from 4.48 billion in 2024 to 4.97 billion by 2028—a consistent 3% annual growth rate. This expanding market creates opportunity alongside increased competition for inbox placement.

27. Daily email volume will hit 424.2 billion by 2028

Global email traffic is projected to grow from 361.6 billion daily emails in 2024 to 424.2 billion by 2028. This 17% volume increase means ISP filtering algorithms will become more aggressive, making algorithmic solutions increasingly essential.

28. Outlook/Hotmail inbox placement fell 22.56%

Microsoft properties experienced dramatic declines, with Outlook/Hotmail inbox placement dropping from 49.33% to 26.77%—a 22.56% decrease. Brands targeting professional audiences face particular challenges with Microsoft's tightening standards.

29. Office365 experienced the steepest decline at 26.73%

Exchange (Office365) saw inbox placement plummet from 77.43% to 50.70%—the largest single-platform decline among major ISPs. B2B e-commerce brands relying on corporate email addresses must adapt their strategies accordingly.

30. Unsubscribe rates decreased to 0.053%

A positive signal: unsubscribe rates dropped from 0.072% to 0.053% year-over-year in Q4 2024. Recipients who receive emails in their Primary inbox show higher satisfaction and lower unsubscribe intent, reinforcing the revenue value of proper placement.

What These Statistics Mean for E-commerce Brands

The data paints a clear picture: email deliverability is declining across major ISPs, with Gmail's Promotions tab and Microsoft's aggressive filtering creating significant revenue barriers. Traditional solutions—content changes, domain warming, authentication setup—address symptoms rather than root causes.

For e-commerce brands using Klaviyo, the 13.24% year-over-year decline in inbox placement demands immediate attention. Every campaign sent to the Promotions tab represents lost revenue that compounds over time.

Mailmend's partnership model addresses this challenge through proprietary AI that analyzes promotional threshold factors and generates custom code calibrated for each Klaviyo account. The result: Primary inbox placement without content modifications, copywriting changes, or technical infrastructure overhauls—with measurable results on Day 1.

Frequently Asked Questions

How does Mailmend move emails from the Promotions tab without changing content?

Mailmend uses proprietary AI to analyze the combined factors Gmail's algorithms use to categorize emails—the "promotional threshold." The technology generates account-specific custom code that counteracts promotional categorization signals at the technical/header level rather than the content level, enabling Primary inbox placement while maintaining existing email creative and copy.

What kind of results can e-commerce brands expect from improved inbox placement?

Based on documented case studies, brands implementing Mailmend's solution have achieved 50-100% increases in email revenue. Dr. Squatch reported 112% email revenue increase with 42% open rate improvement and 67% CTR increase within 24 hours. StickerYou achieved a Day 1 boost of 20% with 100% increase by month 1 (64% open rate increase, 43% CTR increase). Ministry of Supply saw results within a business day (27% open rate increase, 30% CTR increase). Larsson & Jennings achieved 82% open rate increase and 51% CTR increase. Amberjack saw 54% open rate increase and 51% CTR increase. Clevr Blends achieved 21% open rate increase and 63% CTR increase. Results vary based on current deliverability status and list engagement, but A/B testing within Klaviyo allows brands to measure exact performance lift.

Why has Klaviyo inbox placement declined despite being the leading e-commerce ESP?

Klaviyo's 13.24% decline reflects broader ISP filtering trends rather than platform-specific issues. As Gmail and Microsoft tighten promotional content detection, all ESPs face increased categorization challenges. The decline underscores why Klaviyo users benefit from supplemental algorithmic solutions that specifically address tab placement.

How can brands measure the exact revenue impact of inbox placement?

Mailmend's integration with Klaviyo's native A/B testing infrastructure allows brands to split-test emails with and without the deliverability code. This creates direct measurement of open rate differences, click-through rate variance, and revenue attribution between Primary inbox and Promotions tab placement within existing analytics dashboards.

What distinguishes algorithmic deliverability solutions from traditional consulting?

Traditional deliverability consulting typically requires comprehensive content strategy overhauls, weeks of domain warming, and ongoing technical modifications. Algorithmic solutions like Mailmend operate at the code level, requiring zero changes to email content, copywriting, or marketing workflows. Implementation completes in under 5 minutes with Day 1 results, versus months of gradual improvement with traditional approaches.