Brands that thrive in 2025 understand one core truth: retention is key. And when it comes to retention, email marketing continues to be the workhorse of ROI. With shifting consumer behavior and rising acquisition costs, choosing the right email partner isn’t only helpful – it’s non-negotiable.
If you’re hunting for the top eCommerce email marketing agency to power your lifecycle campaigns, look no further. The 15 following agencies stand out for scale, creativity, and results.
1. InboxArmy
Founded: 2016
InboxArmy is one of the best full-service email marketing agencies offering tailored solutions for eCommerce brands looking to scale customer retention and drive conversions. Known for their deep bench of ESP certifications, they handle campaign production for over 1 billion emails annually across 40+ platforms like Klaviyo, Salesforce Marketing Cloud, and Iterable. Their client roster includes industry giants like Airbnb and eBay, but they also serve growing DTC businesses with performance-focused email programs, including automated flows, deliverability optimization, and dynamic content. With ROI as a metric baked into every campaign, InboxArmy brings both volume and insight to every inbox.
Based in: Texas, USA
Services:
- Campaign management
- Custom email design and coding
- Data analysis
- ESP migration and integration
- Automation strategy
Best for: Large brands, agencies, or eCommerce businesses needing a vendor-agnostic, scalable solution
2. Tequila Sunrise
Founded: 2019
Tequila Sunrise specializes in lifecycle and retention marketing for DTC eCommerce brands, with a heavy focus on Shopify merchants. They’ve helped over 550 brands scale their email revenue, including Obvi, Schoolyard Snacks, and Fat Snax. Notably, they boast a 963.76% average email revenue growth and 9.6x return on email spend in the first 30 days of engagement. Their strategies go beyond automations, building narrative arcs into every campaign. They use rigorous testing frameworks and segmentation to engineer predictable revenue. Their mix of technical fluency and brand storytelling makes them a go-to partner for DTC eCommerce founders.
Based in: California, USA
Services:
- Klaviyo email and SMS strategy
- Creative asset production
- Lifecycle automations
- Retention analytics
Best for: DTC brands scaling past seven figures who need email as a growth engine
3. Fuel Made
Founded: 2013
Fuel Made is a Shopify Plus agency blending CRO with email marketing mastery. Their work with BK Beauty resulted in a 118% lift in order placement rate from welcome flows, while Turbie Twist saw an 87% bump in conversions. They use Klaviyo to design high-performance automation sequences tailored to brand voice and buyer behavior. With tight alignment between UX and retention strategy, they ensure customers encounter personalized messaging from homepage to inbox. Recognized as a top eCommerce email marketing agency, Fuel Made anchors each touchpoint in data, creating systems that actually convert.
Based in: Washington, USA
Services:
- Email marketing strategy via Klaviyo
- Shopify Plus design and development
- CRO audits and testing
- Customer journey mapping
Best for: Brands that want email marketing integrated tightly with web experience
4. &BAM
Founded: 2018
&BAM is an ROI-focused creative email marketing agency with a reputation for entertaining, high-converting campaigns. The agency generated $30M+ in tracked email revenue in 2021 and reports a 1560% average ROI for clients. Built to serve eCommerce brands with bold voices, & BAM thrives at the intersection of conversion science and creative chaos. They design sequences that feel like entertainment while pulling serious revenue through welcome flows, promotions, and post-purchase loyalty content. For brands that think copywriting is their competitive edge, this team delivers.
Based in: New York, USA
Services:
- Full-funnel email campaigns
- Content strategy and copywriting
- Customer retention flows
- Campaign analytics
Best for: Brands that value voice, wit, and creative differentiation
5. Mattered
Founded: 2020
Mattered helps eCommerce brands build lasting emotional connections through thoughtful storytelling and data-backed personalization. Their email programs reflect a brand’s mission and ethos, often resulting in above-average open and click-through rates across customer lifecycle stages. Rather than template-driven automation, Mattered emphasizes hand-crafted flows with meaningful segmentation. Their campaigns often weave in values-driven narratives, making them ideal for purpose-led eCommerce brands that want to market with integrity and resonance.
Based in: Toronto, Canada
Services:
- Narrative-driven email strategy
- Segmentation and A/B testing
- Onboarding and win-back flows
- Loyalty and retention design
Best for: Purpose-driven brands or early-stage companies wanting soul in their messaging
6. Rejoiner
Founded: 2011
Rejoiner merges software with done-for-you services, targeting lifecycle campaigns and abandoned cart recovery for high-volume eCommerce businesses. Their clients report over 30% increases in email revenue, supported by personalized workflows, dynamic content modules, and predictive analytics. What sets them apart is their proprietary technology stack paired with an agency mindset. Rejoiner works well for brands needing granular data integration and compliance in high-regulated product categories. Their full-service team acts as an extension of internal marketing departments.
Based in: Rhode Island, USA
Services:
- Cart abandonment programs
- Post-purchase campaigns
- ESP management
- Data-driven segmentation
Best for: High-volume merchants seeking tech-enabled service at scale
7. MH Digital
Founded: 2017
MH Digital is a boutique consultancy focused on building and optimizing email strategies for eCommerce brands across various verticals. The agency delivers personalized lifecycle marketing through behavioral segmentation, advanced automation, and iterative testing. Its team works closely with clients to align email workflows with user behavior, aiming to increase engagement and purchase frequency. MH Digital operates with a lean, high-touch model and supports platforms like Klaviyo, Iterable, and Mailchimp.
Based in: Colorado, USA
Services:
- Email strategy and execution
- Lifecycle automation
- ESP implementation and optimization
- Campaign analysis and testing
Best for: DTC and omnichannel brands looking for custom email strategies without relying on prebuilt automation templates.
8. Stimulate
Founded: 2020
Stimulate is a retention-focused marketing agency that helps eCommerce businesses grow revenue by improving customer lifetime value. Their systems aim to reduce churn and deepen loyalty using data-backed lifecycle planning and content personalization. They have delivered tens of millions in attributed email and SMS revenue, showing consistent short-term performance gains across channels. Stimulate works with growth-stage companies seeking stability beyond new customer acquisition.
Based in: Florida, USA
Services:
- Email marketing and automation
- SMS segmentation and optimization
- Lifecycle strategy development
- Direct mail and upsell retention tactics
Best for: Fast-scaling eCommerce brands prioritizing long-term retention and profit margins over short-lived acquisition spikes.
9. Kas Andz Marketing Group
Founded: 2018
Kas Andz Marketing Group focuses on maximizing conversion rates for online brands by refining email performance, deliverability, and on-site behavior. Known for its precision and performance tracking, the agency uses systematic CRO and email testing to drive sustained revenue improvement. Their team supports eCommerce clients aiming to convert traffic more effectively while also fixing bottlenecks in funnel progression and inbox visibility.
Based in: London, United Kingdom
Services:
- Email marketing consultancy
- Conversion rate optimization (CRO)
- Email deliverability diagnostics and remediation
Best for: Online stores with stable traffic seeking to turn more clicks into sales and improve email placement rates.
10. Intelligence Media
Founded: 2019
Intelligence Media offers performance marketing services tailored to growth-stage eCommerce brands. With an emphasis on measurable outcomes, the agency handles email and SMS deployment, conversion optimization, and media buying. Their small team builds custom strategies and has contributed to over $300 million in cumulative revenue for clients. They specialize in producing high-performing creatives backed by iterative testing and full-funnel analytics.
Based in: Riga, Latvia
Services:
- Email and SMS campaign creation
- Conversion rate optimization
- Paid media management
- Content strategy and CMO consulting
Best for: Brands wanting a high-velocity, data-first marketing team focused on scaling revenue across multiple channels.
11. NP Digital
Founded: 2017
NP Digital is a global digital marketing firm offering integrated solutions for eCommerce brands, including multichannel email support. With deep expertise in analytics, media strategy, and content design, the agency executes full-funnel programs that link email with broader acquisition efforts. Their team often complements internal marketing departments, working across email strategy, web UX, and paid media to align efforts and compound returns.
Based in: Illinois, USA
Services:
- Email campaign management
- A/B testing and funnel optimization
- Omnichannel strategy development
- Data insights and dashboarding
- Web design and creative services
Best for: Larger brands with complex martech needs and a preference for omnichannel strategy under one roof.
12. Chronos Agency
Founded: 2017
Chronos Agency is a lifecycle marketing firm focused on profit scaling for DTC eCommerce brands through retention-driven strategies. With a team of over 80 specialists, the agency has worked with more than 500 brands globally, deploying performance marketing across email, SMS, and push channels. Their methods emphasize store audits, behavior-based segmentation, and custom creative production aimed at increasing customer lifetime value. Known for delivering ROI-focused automation and rigorous A/B testing, they position email as a primary profit lever for growth-stage businesses.
Based in: Sydney, Australia
Services:
- Email marketing
- SMS and push notification campaigns
- Flow and automation optimization
- Content calendar planning
- A/B testing and performance tracking
Best for: Mid to large DTC brands seeking to elevate retention through a structured lifecycle marketing program.
13. Adventure Digital
Founded: 2012
Adventure Digital is a digital performance agency helping eCommerce businesses navigate paid growth, especially during launch and early-scale phases. Their team delivers campaign strategy, funnel planning, and creative development across major ad platforms, emphasizing acquisition for brands in industries like beauty, wellness, and financial services. They combine tactical execution with creative problem-solving, supporting budgets from $2K to $100K monthly while offering hands-on campaign refinement.
Based in: Sydney, Australia
Services:
- Paid advertising (Meta, Google, TikTok)
- Email marketing
- Conversion funnel optimization
- Strategic campaign planning
- Landing page development
Best for: High-growth brands needing experienced media buying and scalable acquisition frameworks.
14. King Pixel Digital Marketing
Founded: 2017
King Pixel Digital Marketing is a boutique agency specializing in conversion-focused digital marketing for Shopify merchants and eCommerce retailers. They deliver funnel design, paid advertising, and retention strategies through email and SMS campaigns, aligning pre- and post-purchase touchpoints. The agency’s lean structure allows them to adapt quickly, making them a solid choice for early-stage brands looking to scale through experimentation and data-led refinement.
Based in: Adelaide, Australia
Services:
- Funnel building and CRO
- Paid advertising
- Email and SMS automation
- Content and brand messaging
- Shopify growth strategy
Best for: Niche and independent online stores prioritizing flexibility and custom-built growth systems.
15. Hustler Marketing
Founded: 2018
Hustler Marketing is a retention marketing agency specializing in high-converting Klaviyo email and SMS strategies for eCommerce companies. Operating with a distributed team, they focus on full-funnel email program builds – from audits and segmentation to creative and peak season execution. Their work has supported a global client base with a strong emphasis on customer re-engagement, repeat purchase flows, and campaign optimization.
Based in: Wyoming, USA
Services:
- Email marketing and lifecycle flows
- SMS campaign management
- Customer segmentation and targeting
- Seasonal and product launch campaigns
- Performance tracking and iteration
Best for: DTC brands using Klaviyo that want comprehensive done-for-you retention marketing support.
What Makes a Top eCommerce Email Marketing Agency?
Choosing the right partner means more than comparing portfolios. The top eCommerce email marketing agency will match your growth stage, technical stack, and creative tone.
There are 4 main traits that separate specialists from generalists and make the investment worth every penny. After all, in a saturated inbox, relevance wins.
Look for agencies with:
- Platform fluency, especially with Klaviyo or other ESPs your stack relies on
- Proven revenue gains across multiple lifecycle stages
- A balance between strategy and execution
- Clear, measurable ROI within 30-90 days
Final Thoughts
The top eCommerce email marketing agency for your business depends on more than your budget. It’s about finding a partner that understands your brand’s voice, works well with your tech stack, and can execute at the pace your growth demands. These 15 contenders have shown that, when done right, email not only performs but also delivers compounding results.
If your retention metrics are stalling despite traffic or spend, it’s probably time to find a top eCommerce email marketing agency to partner with. In this space, clarity beats complexity, and precision beats noise.
