Top 10 Cold Email Marketing Agencies in the UK for Startups

Cold outreach might sound simple, but turning a cold email into a booked meeting takes precision, patience, and the right strategy. That’s why partnering with a professional cold email marketing agency can completely transform your pipeline. These specialists blend audience research, compliant data, persuasive copy, and deliverability expertise to turn unread emails into real conversations.

Behind every high-performing cold email programme sits serious infrastructure, domain setup, warm-up sequences, inbox rotation, and reputation monitoring. Modern agencies rely on tools like Manyreach to handle this technical foundation, allowing them to focus on what really matters: results.

Let’s explore the ten cold outreach agencies leading the UK market in 2025.

Top 10 Cold Email Agencies in the UK: 2025 Update

Finding the right cold emailing agency can be challenging when so many promise the same thing, leads, meetings, and growth. To simplify your decision, this list focuses on agencies that demonstrate:

• First we focused on each agency’s cold email processes including list-building, sequencing, and deliverability control.
• Then we looked into their defined range of services, from single-channel campaigns to full SDR operations.
• After that we focused on their case studies and client success metrics.
• Finally, we looked into their experience in high-value B2B industries such as SaaS, IT, and professional services.

The Agencies

• Flowd
• Beanstalk
• GrowLeady
• We Are Team Rocket
• Inside Sales Solutions
• Inbox Leads
• CMFG – The B2B Marketing Agency
• Cobra Contact
• Fractional Teams
• Appointment Setter Online

1. Flowd

Flowd is a UK-based cold email agency that specialises in booking qualified meetings for B2B companies. Their data-driven campaigns combine handcrafted messaging with advanced targeting to deliver predictable results.

Why They Stand Out: Flowd focuses on measurable ROI, continuous testing, and bulletproof deliverability—ideal for businesses seeking consistent, sales-ready appointments.

Key Services:

• Cold Email Strategy & Execution: Flowd designs data-driven, personalized email sequences built around each client’s ICP. So they make sure of higher engagement, improved open rates, and consistent conversions across campaigns.
• Inbox Management & Deliverability: Their experts handle domain setup, warm-up, and sender reputation monitoring to maintain strong inbox placement, prevent spam issues, and safeguard long-term deliverability performance.
• ICP Research & List Building: Flowd’s research team develops verified, compliant prospect lists aligned with your ideal customer profile, using multi-source data and in-depth segmentation for accuracy.
• Meeting Scheduling: They manage the entire scheduling process, booking qualified meetings directly with decision-makers to create a ready-to-close sales pipeline and shorten conversion cycles.

Revenue: $8.8 Million

Company Size: Small to mid-sized

Location: United Kingdom (serving UK/EU/US)

Pricing: Custom plan based on scope

2. Beanstalk

Beanstalk, founded in 2009,  blends telemarketing and cold outreach to deliver fully managed lead-generation programmes for UK B2B firms.

Why They Stand Out: Their long-standing SDR model combines human touch with technology, offering reliability for businesses that prefer steady, relationship-driven outreach.

Key Services:

• Email Campaign Management: Beanstalk creates thoughtful and engaging email campaigns that help businesses start meaningful conversations with verified decision-makers across multiple industries.
• SDR & Telemarketing Support: Their experienced sales reps combine personalised email outreach with expert phone engagement to increase contact rates and boost overall campaign response.
• Lead Qualification & Appointment Setting: The team carefully screens and qualifies leads, booking meetings that align with your ICP so your sales team focuses only on high-value prospects.
• Data Research & Reporting: Beanstalk collects accurate, up-to-date B2B contact data and provides transparent reports that help clients monitor performance and continuously improve campaigns.

Revenue: $2.3 Million

Company Size: 15 employees

Location: United Kingdom

Pricing: Retainer model based on volume and targets

3. GrowLeady

GrowLeady delivers tailored cold email lead generation and LinkedIn outreach for growth-stage B2B companies. They specialise in handcrafted messaging that drives meaningful responses.

Why They Stand Out: Their programmes blend one-to-one personalisation with smart automation, ensuring every email feels human while operating at scale.

Key Services:

• Cold Email Outreach: GrowLeady designs hyper-personalised cold email campaigns that nurture relationships, improve reply rates, and convert interested prospects into booked meetings efficiently.
• LinkedIn Prospecting: Their team combines email with LinkedIn outreach to build credibility, foster connections, and expand client visibility among high-intent decision-makers.
• ICP Definition & List Building: They define and refine your ideal customer profile, creating segmented, compliant contact lists that enhance precision targeting and campaign results.
• Sales-Ready Appointment Setting: GrowLeady handles prospect follow-ups and schedules high-quality meetings with sales-ready leads, maximising both efficiency and conversion potential.

Revenue: <$5 Million

Company Size: <15 employees

Location: United Kingdom

Pricing: Custom proposal per ICP and channels

4. We are Team Rocket

Team Rocket positions itself at the crossroads of intent-data-driven ABM and cold outreach. They help companies capture in-market prospects before competitors even reach them.

Why They Stand Out: Their approach goes beyond email lists, using buyer-intent signals to determine timing, interest, and messaging relevance.

Key Services:

• Intent-Based Cold Outreach: Team Rocket identifies prospects actively showing buying intent and engages them with tailored outreach that resonates with their current stage of awareness.
• Account-Based Marketing (ABM): They execute coordinated campaigns across email, LinkedIn, and other digital channels, focusing on the right accounts with precision and persistence.
• Pipeline Management: Their experts track and analyse every step of the outreach journey, adjusting campaigns to improve engagement and accelerate revenue growth over time.
• Lead Nurturing: Team Rocket maintains consistent communication through follow-ups and emails that build credibility and trust throughout the sales cycle.

Revenue: Not published

Company Size: 11-50 Employees

Location: United Kingdom (with global clients)

Pricing: Retainer or custom model

5. Inside Sales Solutions (ISS)

ISS is a full-service cold emailing agency and SDR provider that helps B2B tech companies penetrate new markets and scale their pipeline globally.

Why They Stand Out: ISS combines experienced SDR teams with strong compliance practices and deep industry knowledge—ideal for enterprise sales cycles.

Key Services:

• Outsourced SDR Programmes: ISS provides dedicated sales teams that handle cold email outreach, lead qualification, and appointment-setting, giving clients full outbound capacity without internal hiring.
• Cold Email Campaigns: Their specialists create well-researched, compliant email sequences that engage decision-makers and generate qualified leads from target accounts efficiently.
• B2B Data Research: ISS delivers reliable contact data and conducts detailed research to ensure all prospects meet your ideal profile and comply with data regulations.
• Sales Consulting & Enablement: They align your outbound campaigns with your sales objectives, providing expert strategy, training, and insights that optimise long-term performance.

Revenue: $44.2 Million

Company Size: 130 employees

Location: Florida, USA

Pricing: Custom based on scope and region

6. Inbox Leads

Inbox Leads is a boutique UK cold email marketing agency dedicated to helping businesses generate predictable meeting flow through targeted outbound.

Why They Stand Out: Their promise is simple—deliver conversations that matter. Inbox Leads focuses on high-quality data and compliant outreach rather than mass emailing.

Key Services:

• Cold Email Campaign Setup: Inbox Leads builds structured, high-performing outreach campaigns that focus on meaningful engagement rather than high-volume generic messaging.
• Domain & Deliverability Management: Their team configures and authenticates domains, monitors sender reputation, and ensures every email has the best chance to reach the inbox.
• Custom Prospect Lists: They curate verified, segmented lists of target contacts matched precisely to your ICP, ensuring compliance and strong data accuracy.
• Meeting Booking Services: Inbox Leads takes care of scheduling confirmed meetings with qualified leads, streamlining your sales process and improving conversion speed.

Revenue: <$5 Million

Company Size: 2–10 employees

Location: Cambridge, UK

Pricing: Custom quote after qualification

7. CMFG – The B2B Marketing Agency

CMFG operates as a flexible cold email and lead-generation partner that can also function as your fractional marketing team.

Why They Stand Out: They integrate creative, brand, and outbound efforts under one roof, ensuring consistent messaging from prospecting to nurture.

Key Services:

• Cold Email & Lead Generation: CMFG runs precision-targeted email campaigns designed to generate consistent B2B leads while maintaining brand voice and authenticity.
• Brand Messaging & Creative Support: Their creative experts craft engaging narratives and visuals that align with outreach messaging and strengthen audience connection.
• Sales Enablement Materials: They produce sales decks, scripts, and content tools that support outbound teams in building persuasive, trust-based conversations with leads.
• Campaign Analysis & Optimisation: CMFG analyses campaign metrics, refines copy, and improves performance through ongoing testing and data-backed insights.

Revenue: Not published

Company Size: 2–10 employees

Location: London, UK

Pricing: Project or retainer basis

8. Cobra Contact

Cobra Contact provides AI-assisted SDR and cold outreach programmes that help founders and B2B teams book sales-ready meetings quickly.

Why They Stand Out: They merge automation with human review to balance scale and quality, offering a fast-moving but well-governed outreach process.

Key Services:

• AI-Driven Cold Outreach: Cobra Contact uses advanced automation combined with human quality control to create scalable, data-led cold email campaigns that drive measurable growth.
• Sales Development Support: They function as a flexible SDR team, handling prospecting, qualification, and communication on behalf of growing B2B organisations.
• Data Research & Prospecting: The agency uses intelligent software and manual validation to find and verify the right prospects within your target industries.
• Meeting Booking & Reporting: Cobra Contact handles scheduling while delivering transparent performance reports that help clients understand ROI clearly and confidently.

Revenue: Not listed

Company Size: 2–10 employees

Location: United Kingdom

Pricing: Custom retainer

9. Fractional Teams

Fractional Teams offers go-to-market consulting and cold email lead generation for B2B tech, Cloud, and IT companies seeking strategic outbound execution.

Why They Stand Out: Their combination of technical expertise and marketing strategy makes them ideal for firms that sell complex solutions and need precision targeting.

Key Services:

• Cold Email & ABM Campaigns: Fractional Teams combines cold email with account-based marketing to target decision-makers through thoughtful, multi-touch engagement.
• Go-to-Market Strategy: They define positioning, messaging, and targeting strategies that help businesses align marketing and sales for consistent growth.
• Prospect List Building: Their experts create clean, validated lists of prospects within your industry niche, ensuring relevance and better conversion opportunities.
• Sales Playbook Development: Fractional Teams build step-by-step outbound playbooks that make scaling your internal sales operations smooth and efficient.

Revenue: Not disclosed

Company Size: 11–50 employees

Location: United Kingdom

Pricing: $399.69 Per Month

10. Appointment Setter Online

Appointment Setter Online focuses on appointment setting and lead generation through a cold email and calling mix, offering flexible commercial models.

Why They Stand Out: They provide pay-per-appointment and retainer options—ideal for companies wanting predictable ROI without long commitments.

Key Services:

• Cold Email Outreach: Appointment Setter Online creates persuasive email sequences that turn cold prospects into booked meetings and active opportunities for your team.
• Appointment Scheduling: Their specialists coordinate every stage of scheduling, ensuring smooth communication and minimal friction between your team and prospects.
• Cold Calling Integration: They combine targeted phone outreach with email follow-ups to improve connection rates and maximise qualified lead conversions.
• Performance Reporting: Appointment Setter Online provides detailed campaign analytics that give clients visibility into engagement, meetings booked, and overall ROI.

Revenue: Not published

Company Size: Not listed

Location: United Kingdom

Pricing: $1099 Per Month

Selection Criteria

Before finalising our list of the top 10 cold email marketing agencies in the UK, we applied a careful evaluation process. Each agency was reviewed not just for its claims, but for the consistency, and credibility behind its work. 

So we focused on four pillars that define long-term success in cold outreach.

Performance and Proven Impact

At the core, we valued agencies that don’t just send campaigns, but deliver measurable business outcomes. We aimed for teams that consistently generate qualified leads, meaningful meetings, and tangible ROI earned higher marks.

So we analyzed client case studies, success stories, and verifiable metrics like reply rates, conversion ratios, and sales pipeline growth. 

Agencies with a proven ability to perform across different industries and sustain relationships over time stood out as reliable partners rather than one-off vendors.

Personalisation and Use of Technology

Cold email isn’t about volume anymore; it’s about precision. We gave preference to agencies that balance human-led research with smart automation, advanced segmentation, and AI-supported optimisation.

These teams treat data as more than numbers; they use it to craft emails that sound natural, relevant, and timely. Their use of automation tools enhances efficiency without losing the personal tone that makes a cold email feel genuine.

Reputation and Client Experience

Transparency was a defining factor in our evaluation. The most trusted agencies are open about their process, reporting, and results. We examined client reviews, testimonials, and long-term engagement histories to understand their reputation for accountability.

Compliance also mattered, so we made sure that each in our agency follows GDPR and PECR regulations.

Scalability and Strategic Thinking

Finally, we assessed how each agency adapts to change. The best teams can launch small, test-focused pilots, analyse data quickly, and scale campaigns responsibly. They listen to feedback, evolve with client needs, and adjust to shifts in market behaviour or technology.

These agencies share one thing in common: a strategic, data-backed approach to sustainable growth, whether serving a startup chasing early traction or an enterprise expanding internationally.

How to Choose the Right Cold Email Agency

Here’s how you can select the right cold email agency for your faster growth of your startup:

1. Define Your ICP First: Success starts with knowing who you want to reach. The right cold emailing agency will help you sharpen industry, role, and pain-point criteria before writing a single email.

2. Prioritise Deliverability: Even the best copy fails if it lands in spam. Choose partners that can show their domain warm-up and sender-reputation processes.

3. Review Testing & Iteration: Great agencies test everything—subject lines, CTAs, timing, and follow-ups—and adjust based on data, not guesses.

4. Pick the Right Pricing Model: Retainers work best for long-term optimisation; pay-per-appointment models suit shorter, ROI-focused pilots.

5. Confirm Compliance: Ensure any cold outreach agency adheres to UK GDPR and PECR rules with legitimate interest assessments and clear opt-outs.

How Manyreach Can Help

Managing hundreds of daily emails manually isn’t scalable. That’s where Manyreach comes in. It enables agencies and in-house teams to:

• Automate Mailbox Management: Add and rotate domains safely.
• Protect Deliverability: Warm up new addresses and monitor sender reputation.
• Collaborate at Scale: Add unlimited users and workspaces for seamless team alignment.
• Track Results in Real Time: Analyse opens, replies, meetings, and conversions to improve every campaign.

Start your next campaign with Manyreach—the complete outreach platform for agencies.

FAQs

Q1: Is cold emailing legal in the UK?

Yes. It’s legal under PECR and UK GDPR when there’s a legitimate interest, clear identification, and an easy opt-out link.

Q2: What response rate can I expect?

Typical campaigns yield 3–10 percent positive replies, depending on your ICP, copy, and sender reputation.

Q3: Should I use multichannel or email-only outreach?

Email works well alone, but combining LinkedIn and calls usually boosts conversions, especially for enterprise sales.

Q4: How fast will I see results?

Most businesses start seeing traction within four to six weeks once domains warm up and sequences mature.

Q5: How do agencies build their contact lists?

They blend licensed databases with manual research, verifying emails and roles for accuracy and compliance.

Conclusion

Selecting the right cold email marketing agency can be the difference between random outreach and a reliable revenue engine. The agencies on this list: Flowd, Beanstalk, GrowLeady, and others combine research, personalisation, and deliverability mastery to help UK businesses grow faster through intelligent outbound.

If you’d rather control your outreach internally, Manyreach equips your team with the same infrastructure. These agencies rely on automated warm-ups, smart sending, and detailed analytics, so you can scale confidently and compliantly in 2025.