Client Background

Dimitar Petkov transitioned from solo freelancer using simple email tools to head of LeadHaste, an agency specializing in scaling deeply personalized B2B outbound campaigns. Initially limited by manual tools which lacked API support, efficient multi-inbox scaling, and robust deliverability—Dimitar sought industry-grade solutions that could help his clients grow beyond browser extension limitations, reliably reach prospects, and automate internal operations.

Challenges

• Early tools couldn’t expand past a handful of inboxes, limiting client campaign scope.
• Manual setup and lack of pre-campaign checks led to high bounce rates and inconsistent sender reputation.
• No bulk reporting, global block listing, or automated workflow/notifications meant lost opportunities and inefficiency.
• No API connections to integrate reporting, notifications, and CRM with operational platforms like Airtable, ClickUp, or client CRMs.

Solutions & Approach

LeadHaste adopted Smartlead to overhaul its outbound infrastructure.

Multi-Inbox Scaling

Leveraged Smartlead’s reseller and vendor tools to onboard hundreds—sometimes thousands—of inboxes at once, eliminating bottlenecks and saving immense setup time.

Smart Deliverability

Used SmartServers, campaign-level and domain throttling, and advanced pre-send deliverability tests to ensure high inbox placement.

API Automation

Connected Smartlead with ClickUp and Airtable, automating notifications, client reporting, blocklists, and campaign health, allowing the agency to operate lean and scale fast.

Master Inbox & Analytics

Used master inbox features to unify client engagement, and new analytics dashboards to rapidly assess campaign performance, date ranges, and reply health percentages.

Continuous Improvement

Benefited from Smartlead’s regular product updates, new features for data handling, email campaign diagnosis, and mailbox issue insights—constantly adapting to shifting industry standards.

Data Enrichment & Personalization Strategy

• Deep Scraping: Used Apollo and Google Maps scraping (via N8n, Serper) and browser extensions like Instant Data Scraper to build ultra-precise lead lists for each campaign.
• Multi-Tool Verification: Enriched leads via Clay, Xenero, and custom API integrations, verifying emails, adding firmographics, and customizing each email sequence.
• Hyper-Personalization: Each email was relevant, non-generic, and crafted to drive engagement—avoiding robotic outreach.

Campaign Results

HelpMatch (Client-Verified)

• From zero to $100k revenue in 9 months with Smartlead-powered campaigns.
• Averaged 1,500 buyer conversations per month, 28% reply rate, and 80% positive reply rate.
• Achieved $100k closed pipeline by month 9.

Aviloo (Battery Diagnostics, EU/Global Expansion)

• Overcame fragmented EU cold outreach with localized, multi-language sequences.
• Generated 50+ in-person meetings, 500+ positive replies, and 20+ confirmed new sales.
• SDR team freed to focus on top prospects, not just manual prospecting.

Tribecast (YouTube Influencer Channel Deals)

• Automated outreach for premium influencer deals, targeting channels with 2M+ downloads.
• Netted 400+ positive replies, 4.7% reply rate, and 32% positive reply rate.
• Mass outbound became feasible through creator-specific campaign engines and fast iteration cycles.

Typical LeadHaste Campaign Metrics

• Campaigns routinely ran to over 10,000 leads at a time.
• Recent HelpMatch launch delivered 10,800 leads, 3,200 replies (30% reply rate), and 2,500 positive replies (80% positive rate), with bounce rates under 2%—well above industry average.

Technical Advantages

Deliverability Management 

Campaign setup included SmartServer assignment, deliverability tests, inbox health checks, and global analytics. Reply detection, bounce management, and mailbox issue flags protected sender reputation.

API Flexibility

Allowed custom CRM notifications, reminders, and reporting. Manual steps like data export, blocklisting, and response monitoring became automated.

Feature Velocity

Smartlead released major new features—like domain throttling, master inboxes, extended analytics—nearly every week, keeping LeadHaste on the industry’s leading edge.

Future Needs From Smartlead

• The agency seeks deeper CRM workflow—more robust reminders, automated deal stage triggers, and easier notification setups.
• New vendor integrations and mailbox management enhancements continually strengthen LeadHaste’s ability to add clients and launch new verticals.
• Dimitar noted the value of being able to easily export campaign data for use in enrichment/personalization tools like Clay.

Lessons Learned

• Even the best offers will be wasted if emails don’t reach inboxes—an area Smartlead excels at solving.
• API access allowed LeadHaste to scale efficiently, maintain data quality, and reduce operational overhead.
• Smartlead’s frequent product releases mean agencies like LeadHaste can stay ahead of changes in deliverability, compliance, and market tactics.
• Targeted, custom outreach proved critical, shown by reply rates far exceeding generic approaches.

Conclusion

LeadHaste’s transformation into a scalable outbound powerhouse was fueled by Smartlead’s advanced deliverability controls, API-driven automation, rapid feature development, and hyper-personalized campaign management. 

These tools enabled the agency to go from a few inboxes to thousands, support multi-market growth, and achieve exceptional response, reply, and conversion metrics—including scaling HelpMatch from zero to $100k in less than a year. 

LeadHaste continues to thrive by pairing data and human insight with leading-edge automation—delivering real, measurable results for clients in Europe, North America, and beyond.

Your business can achieve similar results with Smartlead. All you have to do is check out our 14-day trial and see how it can transfer your cold email outreach.