Customer Success Stories

Real results from companies that transformed their email deliverability with Lero. From startups to enterprises, see how we help businesses achieve 97.3% validation accuracy.

2.8M+

Emails Validated

89%

Avg Bounce Reduction

$75K+

Total Savings

27%

Avg Deliverability Boost

FinanceFlow logo

FinanceFlow

FinTechSeries A Startup

FinanceFlow was experiencing 15% email bounce rates on their customer onboarding campaigns, significantly impacting user activation and causing deliverability issues with major email providers.

85%

Bounce Rate Reduction

Solution

Implemented Lero's API for real-time email validation during signup and ran their existing 50K customer database through our bulk validation service.

Key Metrics

15.2%

Bounce Rate Before

2.3%

Bounce Rate After

+23%

Deliverability Increase

$4,000

Monthly Cost Savings

What They Say

"Lero transformed our email deliverability overnight. We went from 15% bounce rates to just 2.3%. The ROI was immediate - we're saving thousands on wasted sends and our email reputation has never been better."
Sarah Chen profile
Sarah Chen
Growth Engineer, FinanceFlow
175,000

Emails Validated

30 days

Implementation

ShopSmart logo

ShopSmart

E-commerceMid-market

ShopSmart needed to clean their 500K subscriber list before launching a major Black Friday campaign, with concerns about hitting spam folders and damaging sender reputation.

92%

Bounce Rate Reduction

Solution

Used Lero's bulk validation service to process their entire database and implemented real-time validation for all new newsletter signups going forward.

Key Metrics

73,000

Invalid Emails Found

+31%

Open Rate Increase

+156%

Campaign ROI

$1,200/mo

ESP Cost Reduction

What They Say

"Our Black Friday campaign was our most successful ever. Lero's validation caught 73K invalid emails we would have sent to. The campaign hit inboxes instead of spam folders, resulting in 31% higher open rates."
Marcus Rodriguez profile
Marcus Rodriguez
Email Marketing Director, ShopSmart
520,000

Emails Validated

14 days

Implementation

DevTools Pro logo

DevTools Pro

SaaS/Developer ToolsEnterprise

DevTools Pro needed to validate 2M+ emails for their developer newsletter while maintaining high deliverability standards and avoiding ESP throttling issues.

94%

Bounce Rate Reduction

Solution

Integrated Lero's enterprise API with custom rate limiting and implemented batch processing for their massive email database while maintaining real-time validation for new signups.

Key Metrics

2.1M

Emails Processed

50ms avg

Processing Speed

98.1%

Final Deliverability

$180K

Annual Savings

What They Say

"Lero handled our 2M+ email validation seamlessly. Their enterprise API scaled perfectly with our infrastructure. We're now confidently sending to our entire developer community with 98.1% deliverability."
Alex Kim profile
Alex Kim
VP of Engineering, DevTools Pro
2,100,000

Emails Validated

45 days

Implementation

Ready to Join Our Success Stories?

Start validating your emails today and see the same results as our customers. Enterprise accuracy at startup-friendly pricing.

JG

Javier Gil

Founder & CEO

Serial entrepreneur with 10+ years in email technology and deliverability. Previously built and scaled email infrastructure for enterprise clients.

Expertise:

Email DeliverabilityAPI ArchitectureStartup GrowthData Privacy

Written by Javier GilFounder & CEO at Lero