5 best cold email agencies to scale your B2B pipeline

Cold emailing is a staple for generating and winning B2B deals. But an evergreen challenge is making cold emailing work at scale.

After reviewing 300+ client calls about emails, we found a pattern: Most teams have tools, compile prospect lists, and send many emails — yet results remain inconsistent.

• Open rates are low, as inboxes get crowded and filters get stricter.
• Replies don’t convert because of poor targeting or weak messaging.
• Meetings stall because prospects aren’t qualified or engaged.

Here’s a fact: Effective cold email outreach takes more than volume. It requires accurate targeting, personalized messaging, and an airtight cadence and follow-up process. Most internal teams struggle to manage all this, prompting them to seek cold email lead generation agencies.

The top cold email agencies don’t just click “Send”; they bring bandwidth, expertise, and proven playbooks that turn cold leads into qualified sales conversations. 

In this article, I’ll break down what to look for in a cold email partner and highlight the 5 best cold email agencies to help you scale your B2B pipeline.

5 factors to consider when evaluating cold email agencies

1. Does the agency handle deliverability and setup?
2. Can the agency take full ownership of execution at scale?
3. Does the agency book meetings with qualified leads?
4. Does the agency ensure targeting, data, and messaging alignment?
5. Can the agency generate predictable results?

Factor #1: Does the agency handle deliverability and setup?

Poor deliverability is the silent killer of cold email campaigns. 

The best targeting, clear messaging, and a detailed ICP won’t matter if your emails can’t reach inboxes. Thus, your agency shouldn’t overlook technicalities like:

• Domain setup
• Email warmup
• Sender Policy Framework (SPF)
• DomainKeys Identified Mail (DKIM)
• Domain-based Message Authentication, Reporting, and Conformance (DMARC)
• Ongoing sender reputation management

These safeguards prevent mailbox providers from flagging your domain. They keep your emails out of spam folders, help response rates stay steady or rise, and protect your sender reputation.

Belkins’ approach

We don’t just talk about deliverability at Belkins; we own it.

Our clients’ persistent concerns about emails missing the inbox made us develop Folderly, a proprietary software for monitoring and optimizing email deliverability from end to end. We also set up domains, warm inboxes, and monitor sender health throughout every campaign.

Through this, we’ve helped companies like Titan Growth, a digital marketing agency, to achieve a 99% email deliverability rate and an 84% open rate. Similarly, SUJO, a social news app, saw a 100% inbox placement rate and a 90% campaign engagement rate after we fixed their deliverability issues.

We’ve also used Folderly to stabilize Belkins’ deliverability, increasing open rates to 70% and the volume of marketing-qualified leads by 40%.

Factor #2: Can the agency take full ownership of execution at scale?

Lone salespeople or teams usually have the right tech stack like Outreach, SalesLoft, Apollo, or LinkedIn automation tools. 

But based on what we’ve learned from our client conversations, the problem isn’t the tools — it’s the lack of bandwidth to use them. Clients often lack the resources, time, and team capacity required to execute their campaigns.

For example, companies hire sales reps to close deals. However, reps may lack the time needed to prospect, set up email cadences, and follow up with cold leads. This means your agency must have experts dedicated to doing what closers can’t to prevent your campaigns from stalling.

Belkins’ approach

Belkins is a team of 250+ specialists. We have SDRs, account managers, copywriters, lead researchers, and deliverability experts. That means every execution component, from list-building to scripting to follow-up, gets expert attention.

We execute without stretching your team and do end-to-end campaign management all the way to appointment setting with sales-qualified leads.

Take Pairaphrase, an AI-powered translation management system for enterprise teams. Working with them required us to deploy a multifunctional team made up of an account manager, SDR, copywriter, and lead researcher. The result was an 84% cold email open rate, a 16% reply rate, 203 qualified appointments booked in 17 months, and achieving 150% of the monthly quota.

One music agency, CustomChannels, wasn’t any different. We ran a hyper-targeted campaign that generated 115 appointments in 9 months — with an average open rate of 50–55%, a reply rate of 8–10%, and average deal sizes over $10,000. These aren’t one-offs. Our clients say taking full ownership of execution makes us a part of their ongoing customer acquisition strategy.

Factor #3: Does the agency book meetings with qualified leads?

Reaching the benchmark cold email response rate of 5.8% is great. 

But what’s not great is getting unqualified replies. The risk with this is huge. Calling unqualified prospects wastes hours on fruitless conversations and makes pipeline forecasts inaccurate. It also reduces confidence in cold email as a channel.

So, having your agency fill your calendar isn’t enough. All calendar slots should have qualified prospects who can progress through your pipeline.

Belkins’ approach

We book meetings against strict qualification criteria — budget, authority, need, and timing or urgency (BANT). 

Our core goal is to eliminate curiosity calls and tire-kickers by validating intent and fit. Prospects know why they’re meeting, what you offer, and how it connects to their pain points before they ever hit the calendar. This ensures your sales team engages in conversations with prepared buyers.

We do this for all clients, including Get Well, a health tech company. Within 5.5 months of collaboration, we got a 25.4% conversion of email leads to meetings, booking 44 meetings altogether.

Factor #4: Does the agency ensure targeting, data, and messaging alignment?

The success of cold email hinges on sending the right message to the right contact at the right time. This begins with targeting the right (and specific) ideal customer profiles (ICPs). 

A broad ICP makes agencies chase everyone in the market. The outcome is writing and sending messages to people with dozens of roles and priorities at once. Such copy becomes watered-down, generic, and forgettable.

Then there’s contact data. Outdated contacts, scraped lists, and irrelevant job titles make messages miss the mark. They also increase bounces, hurt deliverability, and damage your sender reputation.

Belkins’ approach

We start with ICP refinement and aim all campaigns at decision-makers who match your buying profile. 

Our research team verifies every contact so you’re not emailing bounced addresses or irrelevant titles. Afterward, we create custom messaging tailored to your buyers’ pain points.

Combining clean data with tailored messaging lets us cut through market saturation. That’s how we deliver meaningful results for companies like Whitespots, an application security platform. Before contacting us, Whitespots had a limited workforce and no outreach experience. However, they wanted qualified appointments and niche expansion. 

We analyzed their goals, defined their ICP, supported them by creating inbound materials, found the correct time and cadence to email their ICP, and created cold email templates. 

The result? 10 booked appointments in 1 month, 1,000 MQLs added to the pipeline, and $200,000 of new revenue.

Factor #5: Can the agency generate predictable results?

Every agency should deliver on agreed outcomes.

But we know that rarely happens. We’ve heard from clients who fell for wild promises — “400 meetings in 90 days” — only to get inconsistent results, low-quality meetings, and barebone reports. This lack of transparency erodes trust and reduces predictability.

Predictability comes from repeatable systems and consistent delivery. To assess an agency’s capacity to deliver predictable outcomes, look for social proof — case studies, testimonials, and third-party reviews.

Belkins’ approach

We have third-party reviews on Clutch and G2. With an average rating of 96% across both platforms and proven case studies, we make your results predictable. 

The icing on the cake is our transparency. We don’t chase vain meeting targets. We align with your revenue goals and calculate the number of qualified leads needed to hit them. You’ll always know:

• What we’re doing
• When you’ll see results
• How our process will integrate with your team

Once your campaign takes off, assessing results is easy. There’s no smoke and mirrors — just reporting tied to pipeline impact. We track metrics like:

• Lead-to-appointment
• Growth in average deal size
• Customer acquisition cost
• Cost-per-appointment reduction
• Emails sent, along with their delivery, engagement, and reply rates
• Appointment-to-closed-won conversions
• Meetings booked weekly and monthly
• Prospects engaged vs. reached
• No-show percentages
• Types of responses

Our predictable system and transparency are what our customers trust. That’s why over 90% of our clients renew: They know what to expect and can plan their revenue targets with outbound as a reliable growth lever.

5 best cold email agencies for lead generation

Our list of the best cold email agencies is based on the factors I shared above.

Belkins: Best for medium-sized to enterprise companies needing full-service global campaign execution

Industry focus: Manufacturing, legal, B2B healthcare, cybersecurity, marketing and creative agencies, SaaS, Fintech

Notable clients: Cisco, Born & Bred, Smartrek, GE HealthCare, Sekisui, Berkeley College, Columbus Chamber of Commerce, Shelby Williams, DeepDyve

Pricing: Starts at $5,500. Final cost depends on variables like market specifics and the number of explorable channels. We also have 3 basic packages with flexible options to accommodate your expectations and goals.

Belkins is proud to be the pacesetter among the best cold email agencies in the U.S. and globally. We have over 8 years of cold emailing expertise, boast a team of 200+ specialists, and have generated over $2 billion in revenue for 1,000+ clients. 

What sets us apart is our ability to cater to the entire user journey and hand you sales-qualified leads. All you need to do is attend booked appointments, run sales negotiations, and sign new deals.

Strengths:

• Strategic approach: We design campaigns by considering where you aspire to be. First, we understand your goals, create detailed ICPs, develop messaging around your unique value, analyze your industry, and size your total addressable market. Afterward, we do a 360-degree channel audit and select the top performers to maximize lead generation and sales. This precision makes every cold email ‌part of a bigger strategy designed to resonate and convert.  
• Manual lead research: Unlike most agencies, Belkins’ dedicated lead research specialists check and validate every lead manually. Not only does this confirm intent and fit, it guarantees high deliverability.
• Omnichannel reinforcement: While cold email is the core channel, we amplify it with LinkedIn and cold calling. This creates multiple engagement and client acquisition pathways.
• Custom outreach strategies: We create unique playbooks for each client. This ensures your strategy aligns with your target market and expected outcomes. We also continuously iterate to get the best performance for all campaigns.
• Scalable execution: From startups booking their first appointments to enterprises needing hundreds of meetings per quarter, Belkins has exceptional experience in scaling outreach predictably.

Awards:

• Inc. Regionals 2024: Mid-Atlantic Winner
• Inc. Best in Business for Climate Change Impact
• G2: Top Lead Generation Service Provider (2024)
• OA500 Top 500 Global Outsourcing Firm Index 2024
• 2023 Globee Awards: Best Use of Technology in Sales (Silver)
• Stevie Awards: Sales & Customer Service (Silver & Bronze), Sales Ethics (Silver)
• Clutch: Top Lead Generation Company (2024), Global Top B2B Service Provider (#9, 2023)
• Corporate Vision Most Innovative B2B Lead Generation Agency 2024 — East Coast U.S.A.

Case studies:

• Simply NUC: Belkins partnered with Simply NUC, a mini-computer manufacturer in the U.S, and built a dependable cold email pipeline. We generated 109 qualified appointments with an 80% open rate, providing a steady stream of leads and allowing the client to focus squarely on closing deals.
• BioSistemika: BioSistemika (a biotech software firm) stopped attending events because of the pandemic. Belkins helped with cold emails, and in 5 months, we delivered 35 new appointments and over $150K in new revenue pipeline.
• An on-demand software services provider: Within 4 months, we secured 48 appointments, which resulted in closing 5 deals and delivering ‌$900K in new project revenue. Campaigns averaged a 40% open rate and a 7% reply rate.

What clients say:

memoryBlue: Best for tech and SaaS companies needing outsourced SDRs trained in cold outreach

Industry focus: SaaS, IT, cybersecurity, health tech, telecommunications, artificial intelligence & machine learning

Notable clients: MobileIron, Box, Blackboard, Cloudera, McAfee

Pricing: Custom

memoryBlue has 20+ years of experience in outsourced sales development. 

With 600+ sales professionals and 2,000+ campaigns, it has built a reputation as a training ground for SDR excellence. They also have a global reach, enabling them to do successful multilingual outreach.

Strengths:

• Proven outbound playbooks: With 20+ years in sales development, memoryBlue brings tried-and-true frameworks for turning cold emails into booked meetings.
• Talent incubation: memoryBlue has an extensive network of in-house trained SDRs. They deploy this network for their sales operations or add talent to clients’ teams when they need extra support.
• Email + phone synergy: Campaigns don’t stop at inboxes — memoryBlue combines cold email with phone follow-ups, ensuring no warm leads slip away.
• Tech industry depth: Their long-standing focus on SaaS, cloud, and cybersecurity means they understand how to pitch technical value propositions in concise, compelling cold emails.

Awards:

• G2’s Summer 2024 Reports Leader in Lead Generation Services and Outsourced Sales Providers
• Spring 2024 Clutch Global Leader for sales outsourcing services
• Clutch recognized memoryBlue as a Top Lead Generation Company in Dallas and a Top Sales Outsourcing Company in the UK and Singapore
• Most Influential B2B Software Business Leader 2024 (Hannah Allen, Director of Global Operations)

Case studies:

• Qualpay: Poor results with a previous agency frustrated Qualpay’s outbound efforts, so they turned to memoryBlue for precision-targeted cold outreach. The outcome: $244M in pipeline created and $115M in closed revenue.
• Asimily: To break into the Middle Eastern and EMEA markets, Asimily relied on memoryBlue’s tailored cold outbound strategy. memoryBlue built a strong brand presence, booked a steady flow of qualified meetings, and accelerated pipeline growth.

What clients say:

Salesroads: Best for technology companies seeking niche outbound sales support

Industry focus: Manufacturing, SaaS, healthcare, logistics, FinTech 

Notable clients: Kuebix, Shell, Microsoft, Parker

Pricing: Custom. Quotes start at $5,500 every month.

Salesroads is a top cold email agency that does multitouch outbound campaigns. They have 17+ years of experience and a team of 100+ sales professionals. The company has set 100K+ appointments for growing companies and built 520 SDR teams. 

Strengths:

• Targeted niche outreach: Proven ability to break into niche markets and generate qualified appointments.
• Client-first culture: Goes above and beyond to ensure clients’ success and long-term satisfaction.
• High-performing SDRs: Experienced SDRs who design and execute end-to-end outbound campaigns to keep sales pipelines full.
• Scalable campaign execution: Trusted to run multiple B2B campaigns with consistent delivery, fast time-to-market, and direct CEO involvement for quality assurance.

Awards:

• Clutch Global Top 1000 Companies 2021 and 2024
• Great Place to Work®: Certified in 2018
• INC5000 Winner (3 times)

Case studies:

• ZoomIn: With an unfocused messaging strategy and minimal outbound activity, ZoomIn partnered with Salesroads to sharpen its value proposition and launch high-impact cold outreach. In 4 months, they secured discovery calls weekly and closed their first deal — ultimately accelerating the momentum that contributed to their acquisition by Salesforce.
• AchieveIt: Struggling to balance prospecting and closing, AchieveIt needed pipeline relief. Salesroads provided a dedicated SDR team and playbook that generated 937 appointments, led to 18 deals worth $540K in ARR, and produced $27M in pipeline.

What clients say:

ColdIQ: Best for B2B companies with a monthly revenue of $100K+

Industry focus: HR software, SaaS, property tech, recruitment, marketing agencies

Notable clients: People Logic, Puzzle, Mindstream News, Varro

Pricing: Custom monthly retainers with customers locked in for the first 3 months.

ColdIQ is a fast-growing B2B outbound sales agency founded in 2020. The agency does end-to-end cold outreach campaign setup & management for companies earning over $100K/month. Similar to Belkins, its goal is to flood your calendar with sales opportunities ripe for closing. 

Strengths:

• Deliverability setup: ColdIQ sets up and warms email inboxes and domains to maximize deliverability. This technical foundation makes outreach campaigns better positioned to avoid spam folders and deliver higher-quality conversions.
• Precise targeting: ColdIQ creates custom email sequences and contextual lead lists built on industry trends and real buying signals — like hiring surges, ad spend, office openings, and acquisitions. This ensures your outreach reaches the right company at the right time.

Awards: No public awards.

Case studies:

• Puzzle: ColdIQ worked with Puzzle, a visual platform for process innovation with outbound prospecting. The campaign brought in 77 qualified meetings in 6+ months.
• Novel: The company wanted to target e-commerce brands that could perform better with shoppable videos. ColdIQ helped in generating 5 to 8 email leads per day, resulting in 1 to 3 customers.

What clients say:

Revit: Best for small to mid-market companies on a budget

Industry focus: SaaS, education, marketing agencies, hospitality, financial services

Notable clients: Umbrelly, Hustler Marketing, ERA Digital

Pricing: Revit offers various prices.

• Custom month-to-month pricing
• 3-month upfront payment pilot. Includes the cost of the first 5 appointments, then pay per appointment
• Corporate plan for larger organizations
• Extra pay-per-appointment fees based on company size ($400–$750)
• Commission-based pricing

Revit is a U.S.-based B2B lead generation agency founded by a mature team with 10+ years of experience in appointment setting. Revit launches 100+ campaigns daily, targeting businesses across 50+ industries. Startups and SMBs choose Revit for its flexible customer acquisition services that maximize results. 

Strengths:

• Deliverability expertise: The team has over a decade of experience, ensuring that they know their way in getting emails into the inboxes of leads.
• Great onboarding: Revit invests in the onboarding process, ensuring every campaign starts with a deep understanding of the client’s goals, target market, and messaging.
• Messaging alignment: They work with clients to refine messaging so it resonates with decision makers and delivers excellent ROI.
• Low-commitment terms: They skip the lock-in. No long contracts — just campaigns built to deliver measurable outcomes.
• Financial flexibility: Revit recognizes that budgets differ and creates solutions matching what you can spend.
• Omnichannel expertise: Revit blends emails, calls, and LinkedIn into a seamless outreach strategy to deliver sales-ready leads.

Awards: No public awards.

Case studies:

• Umbrelly: Umbrelly.cloud is an innovative cloud-based solutions provider. They wanted Revit to optimize their appointment-setting processes, enhance lead generation, and get qualified meetings. Anna Kudla, Product Manager at Umbrelly, said Revit’s performance was outstanding. “They went above and beyond to ensure our satisfaction and exceeded our expectations in every aspect,” she added.

What clients say:

Choosing the right B2B cold email agency

Finding the right cold email partner comes down to your growth stage, industry focus, and sales goals.

Belkins stands out with its full-service and globally scalable execution for medium-sized to enterprise companies. Callbox shines with multichannel campaigns. memoryBlue brings unmatched SDR depth and experience. The Sales Factory excels at targeting. SalesRoad delivers niche expertise.

The key is choosing an agency that not only crafts high-performing cold email campaigns but also integrates seamlessly into your existing sales process, letting you focus on running meetings and closing deals. That’s what we do at Belkins.

If you need support with growing via cold email campaigns, book a strategy call with us.