}

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.
LeadHaste adopted Smartlead to overhaul its outbound infrastructure.
Leveraged Smartlead’s reseller and vendor tools to onboard hundreds—sometimes thousands—of inboxes at once, eliminating bottlenecks and saving immense setup time.
Used SmartServers, campaign-level and domain throttling, and advanced pre-send deliverability tests to ensure high inbox placement.

Connected Smartlead with ClickUp and Airtable, automating notifications, client reporting, blocklists, and campaign health, allowing the agency to operate lean and scale fast.
Used master inbox features to unify client engagement, and new analytics dashboards to rapidly assess campaign performance, date ranges, and reply health percentages.
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.
Campaign setup included SmartServer assignment, deliverability tests, inbox health checks, and global analytics. Reply detection, bounce management, and mailbox issue flags protected sender reputation.
Allowed custom CRM notifications, reminders, and reporting. Manual steps like data export, blocklisting, and response monitoring became automated.
Smartlead released major new features—like domain throttling, master inboxes, extended analytics—nearly every week, keeping LeadHaste on the industry’s leading edge.
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.Â
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.Â
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.

Wajahat Ali is a Technical Content Writer at Smartlead, specializing in the B2B and SaaS sectors. With a talent for simplifying complex concepts, he crafts clear, engaging content that makes intricate topics accessible to both experts and newcomers. Wajahat’s expertise spans across copywriting, social media content, and lead generation, where he consistently delivers valuable, impactful content that resonates with a global audience. His ability to blend technical knowledge with compelling storytelling ensures that every piece of content drives both understanding and results, helping businesses connect with their target markets effectively.
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Founder, StackOptimise
Smartlead's combination of automation, unlimited inboxes, and easy campaign management has completely transformed how we run cold email campaigns.
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Founder, Cold Email Hackers

We have about 15 companies and we use Smartlead for all of them.

Founder, DutchSave Media

One of the things I love about using Smartlead is the deliverability feature. If they landed in the bounce or spam folders, we could resolve this quickly.

Co-Founder, Growth Today

I want to continue to use Smartlead to make operations more seamless - the plan is to bring more clients here and build more SOPs.

Founder, FueltoFly

Smartlead listens to the agencies and customers and builds according to what people want, that has really made things easier for us.

Founder, OutboundSync

We build an infrastructure product, and OutboundSync communicates with Smartlead itself. I love the webhook and API. They're really well done and keep getting better.

Founder, Axoleads

With SmartDelivery, you can put all of that in the hands of the tool. It ensures your emails land in inboxes, and by running a simple test, you can see if you're hitting the mark.

Founder, Claygen
Deliverability is the cornerstone of cold email outreach. You could have the best email copy in the world, but if no one is seeing it, it's useless. I really love the feature where you can actually give client accesses to your clients.

Co-Founder, Cymate

I do not want to switch to another software. Pick a solution you trust, stick with it, and keep refining your copy.

CMO, Avalanche Capital

Managing large volumes of emails through multiple inboxes used to be a logistical nightmare. With Smartlead, the process is seamless. We book thousands of discovery calls through cold emails. These campaigns are generating leads at a scale we never thought possible.

Founder, Growth Engine X

We came for the unlimited inboxes, and we stayed for the API. 1.5M cold emails/month, 7,767+ inboxes managed.

Head of Community & Ecosystem, TxtCart

You cannot replace having 10,000 touches with potential clients. When you have that much distribution and reach, you really start to see incredible results. The simplicity of Smartlead made all the difference. It doesn't require you to be a technical wizard.

Founder, Hyperke

Smartlead has been a game-changer for us. It increased our appointment volume, improved ease of use, and offered valuable features. 80% increase in appointments/month, peak of 276 appointments in a single month.

Founder, Kinetyca

Smartlead has been our cold email backbone from day one. The platform evolves constantly, keeping pace with how deliverability and personalization need to work today. 21% overall reply rate, $175K in 4 months for multiple B2B clients.

Founder, Reachflow

Smartlead is centered around deliverability and constantly evolving. Their API is not like any other platform. Smartlead covers all our needs. The focus on core features like deliverability and API integration is unmatched.

CEO, Halfwarm

Our approach to crafting conversational emails led to reply rates that many of my peers thought were unattainable.

Co-Founder, letstrike

We've grown on zero capital, zero marketing, purely cold emailing - and that's the story we love to tell. The best approach is no approach if you can't handle domain meltdown. The second best is something like Smartlead that's built from the ground up for deliverability at scale.

Founder, Fenixtal

Smartlead's white-labeling and automation let us punch above our weight. The 12M euros sales potential? That's what happens when you combine human creativity with Smartlead's precision.

Co-Founder, Digital Creativs

Nine out of 10. Ninety percent of our clients are on Smartlead unless they come in with an existing setup. That's the default.

Co-Founder, BuildingReach

At the end of the day, you have to take a bet on one tool or another. It was a no-brainer taking that bet on Smartlead. We had to even turn down the volume of our marketing campaigns - Smartlead was capable of driving more volume than our sales team was able to fulfill.

Founder & MD, Prospectiv

Since starting the business in January of this year, we've already generated $200K in sales exclusively from cold email. Smartlead has been central to our operations and has exceeded our expectations.

Founder, Growthlynk

There's so much stuff built on top of it. I would be dead if I had to rebuild it with another tool. I can manage hundreds of senders easily. I can send hundreds of thousands of emails.

Founder, Corebits

The platform's HubSpot integration, real-time Slack updates, and advanced campaign customization have been game changers for our business and our clients'.

Founder, Apex Ascension

From day one, we've never used anything else.


