Best Ecommerce Email Marketing Agency

I've been in the digital marketing industry for nearly two decades. In that time, I've had to refer clients to specialists in channels we don't handle at Searchbloom, and frankly, it's been one of the most frustrating parts of my career. Email marketing is one of those channels. We don't offer it, so when clients need it, I have to send them somewhere else.

Most of those referrals haven't worked out. Agencies overpromise, underdeliver, or treat ecommerce email like it's the same as B2B cold outreach campaigns. It's not. Ecommerce email marketing requires understanding flows, lifecycle triggers, SMS integration, and most importantly, how to turn subscribers into repeat buyers.

After years of trial and error, I finally found agencies I trust enough to recommend. One10 Media is at the top of that list. They've proven themselves with real results, real retention, and the kind of execution that makes me comfortable putting my reputation on the line.

Here's my 2026 list of the 11 best ecommerce email marketing agencies. These are the ones I'd actually send my own clients to.

How I Ranked the Best Ecommerce Email Marketing Agencies

I evaluated each agency against seven criteria that matter for ecommerce brands looking to drive revenue through email and SMS:

• Client Retention Rate

  If brands aren't sticking around, that tells you everything. High retention means the agency delivers results and maintains trust over time.

• Case Study ROI

  I looked for documented outcomes: revenue increases, flow performance, conversion rates, and email-attributed revenue percentages. Not vanity metrics like open rates. Real impact on the bottom line.

• Certifications

  Klaviyo Partner status matters. Elite and Master tiers represent the top fraction of partners. Platform certifications show technical competence and commitment to best practices.

• Third-Party Ratings

  Clutch, GoodFirms, DesignRush, Google Reviews. I pulled scores, review volume, and what actual clients are saying about results and communication.

• Media Mentions & Awards

  Industry recognition, Klaviyo Partner Awards, Inc. 5000 listings, conference speaking. External validation matters.

• Breadth of Services

  Email alone isn't enough anymore. I gave credit to agencies with strong SMS, lifecycle automation, and retention marketing capabilities.

• Team Strength & Culture

  Team size, tenure, specialization. And testimonials that mention communication, transparency, and execution, not just results.

This wasn't a beauty contest. I relied on evidence: publicly available data, client feedback, and direct performance signals. The result is a comparison table that breaks down where each one shines, where they might lag, and why they made the cut.

Rank	Agency	Evaluation Highlights
1	One10 Media Top pick	Client Retention Rate: Exceptionally high retention among DTC brands. One10 Media earns long-term relationships through consistent results and transparent communication. They don't lock clients into lengthy contracts because they don't need to. Results speak for themselves. Case Study ROI: This is where One10 Media separates from the pack. HECS Hunting achieved 955% ROI year-to-date with 219% year-over-year email revenue increase. Bluu generated 2951% ROI in just 5 months, going from $0 to $368K in email revenue. An online coffee retailer saw $680,000+ increased revenue in 5 months with 5.7x revenue per recipient versus industry average. goTIELESS grew email revenue from 13% to 48% of total revenue with SMS revenue increasing over 1000%. These aren't cherry-picked numbers. This is consistent performance across their client base. Certifications: Klaviyo Platinum Master Partner, which puts them in the top tier of Klaviyo agencies globally. Also Meta Business Partner, ActiveCampaign Partner, and Shopify Partner. The certifications reflect genuine platform expertise, not just checkboxes. Third-Party Ratings: 4.9/5 on Clutch with 28 verified reviews and a perfect 5.0/5 "Willing to Refer" score. That last metric matters most to me. It means clients would stake their own reputation on recommending One10 Media. Premier Verified status with Very Low credit risk assessment adds another layer of validation. Media Mentions & Awards: Recognition in industry publications and partner directories. Their case studies have been featured across ecommerce marketing resources. The real validation comes from client results rather than award submissions. Breadth of Services: Full email automation and flows, SMS marketing, campaign strategy, template design, plus paid social capabilities through Meta and Google. They understand that email doesn't exist in isolation. It's part of a retention ecosystem, and they build strategies accordingly. Team Strength: Tight-knit team of 5-10 specialists based in Medina, Ohio. Founded in 2018, so they've built their reputation during the Klaviyo era rather than trying to adapt legacy approaches. Notable clients include Very Special Games (the #1 Amazon board game), Big Berkey Water Filters, Kennedy Blue, HECS Hunting, and Motor City Barrels. The team is small enough that you're working with senior strategists, not junior account managers reading from scripts. Why I Recommend One10 Media: After years of disappointing referrals, One10 Media is the agency I trust with my own client relationships. They understand ecommerce economics, they execute at a high level, and they communicate like partners rather than vendors. When I send someone to One10 Media, I know they'll be taken care of. That's rare in this industry.
2	Tinuiti	Client Retention Rate: Enterprise agency retention with major brand clients staying for multi-year engagements. Scale and resources support complex requirements. Case Study ROI: Bryan Anthonys saw 1,027% increase in email marketing revenue with 281% company revenue lift and 354% increase in customer lifetime value. MVMT Watches achieved 55% email conversion rate growth in 3 months with seven-figure holiday revenue growth. GIR achieved 1118% revenue boost making email their most profitable channel. Certifications: Partners with Braze, Klaviyo, and multiple ESPs. Full-service agency credentials across paid media and lifecycle marketing. Third-Party Ratings: Large agency with extensive case study documentation and industry recognition. Breadth of Services: Full email strategy, ESP management and migration, behavioral triggers, automation, campaign management, creative services, and A/B testing. Part of larger digital marketing suite. Team Strength: Enterprise-scale team with dedicated CRM and Email/Lifecycle division. Notable clients include MVMT, Wag! Labs, Purium, Ivory Ella, and Cuts Clothing.
3	Chronos Agency	Client Retention Rate: Strong retention among fast-growth DTC brands. Clutch Global Award 2024 winner for email marketing excellence validates consistent performance. Case Study ROI: Generated $329 million through email, SMS, and push for clients with 3500% average ROI claimed. Pet Supplies Empire achieved 230% more engaged subscribers. Typical clients see 20-30% revenue increases from email alone. Certifications: Klaviyo Master Elite Partner, the highest certification tier available. Third-Party Ratings: 4.8/5 on Clutch with Clutch Global Leader designation. Strong international reputation. Breadth of Services: Email, SMS, push notification marketing, and full lifecycle automation. Comprehensive DTC retention strategy capabilities. Team Strength: 80+ retention specialists with Singapore and New York offices. Notable clients include The Oodie, Truly Beauty, Beam Suntory, and Quiet Punch.
4	Flowium	Client Retention Rate: Strong retention built on a hands-off model where clients approve campaigns while Flowium handles everything else. The 97% client success rate they claim is backed by consistent Clutch reviews praising long-term partnerships. Case Study ROI: RSVLTS achieved 72% of total revenue from email versus the 30% industry benchmark, with 4.5% click-through rates and 445% increase in average order value. A health supplement company saw 482% surge in email revenue. One shoe brand generated $177.7K highest-ever email revenue representing 36% of total business. Certifications: Klaviyo Master Elite Partner, which is the highest tier available. 2025 Inc. 5000 Honoree validates their growth trajectory. Third-Party Ratings: Perfect 5.0/5 on Clutch with 86 reviews. 100% on-time delivery rate. Consistently praised for execution quality and communication. Breadth of Services: Email marketing strategy, SMS, Klaviyo management, copywriting, design, list growth, lifecycle automation, and RFM analysis. Full-service retention capabilities. Team Strength: 60+ specialists based in Staten Island, NY. Notable clients include True Classic, Dr. Squatch, Swoon, and BetterBrand. Dedicated 6-member teams per client ensures consistency.
5	Underground Ecom	Client Retention Rate: Works with 8, 9, and 10-figure ecommerce brands, indicating strong enterprise retention. Named Klaviyo Partner of the Year 2025 at K:BOS. Case Study ROI: Specific metrics not publicly disclosed, but the agency works with premium brands at significant scale. The Partner of the Year recognition requires exceptional client results. Certifications: Klaviyo Master Elite Partner. 2025 Klaviyo Partner of the Year (EMEA) is the industry's top recognition. Third-Party Ratings: Award winner status establishes credibility among enterprise buyers. Breadth of Services: End-to-end Klaviyo account management, strategy, content creation, split testing, technical support, and reporting. Full-service retention capabilities. Team Strength: 150+ specialists across US and UK managing 400+ accounts. Notable clients include Virgin Experiences, Huda Beauty, Surreal, Osprey, Oh Polly, and Chilly's.
6	InboxArmy	Client Retention Rate: Enterprise-level retention with Fortune 500 clients staying for years. CEO Scott Cohen is the ANA's Email Marketer of the Year, which speaks to industry credibility. Case Study ROI: Sixthreezero bicycles achieved 335% revenue increase year-over-year with 26:1 ROI. Generated more cart abandonment revenue in 2 months than the previous 14 months combined. RCJuice saw 300% email marketing revenue increase in 6 months. Certifications: Klaviyo Silver Master Partner plus expertise across 40+ ESP platforms including Salesforce Marketing Cloud, HubSpot, Marketo, and Mailchimp. The most platform-agnostic agency in the space. Third-Party Ratings: 4.9/5 on Clutch with 70+ reviews. #1 ranked on DesignRush. The volume of verified reviews provides reliable signal. Breadth of Services: Full email campaign management, ESP migrations, deliverability optimization with 95%+ rates, template design, automation, and audits. Can handle complex enterprise requirements. Team Strength: 120+ specialists in Grapevine, TX serving 5,000+ clients across 25+ industries. Enterprise clients include Airbnb, eBay, Spotify, Zappos, and Procter & Gamble.
7	Hustler Marketing	Client Retention Rate: Strong retention among DTC brands, driven by bold creative approaches and consistent revenue results. Elite partner status requires maintaining high client satisfaction metrics. Case Study ROI: BlendJet generates nearly $1M/month in email revenue from a strategy Hustler built from scratch. Ranger Point Precision saw 32% store revenue increase in 3 months. One jewelry brand achieved 69% uplift in email revenue through deliverability fixes alone. A single back-in-stock campaign generated $622,203.60. Certifications: Klaviyo Elite Partner, representing the top 0.2% of partners. Yotpo Premier Partner and one of only 12 agencies on the Yotpo Email Advisory Board globally. Third-Party Ratings: Featured across 7+ industry "best of" lists. Documented $100M+ generated for clients in 2023 alone. Breadth of Services: Email and SMS marketing, Klaviyo flows and campaigns, zero-party data personalization, copywriting, and design. Known for unconventional creative that stands out in crowded inboxes. Team Strength: Manages 80+ clients with 2-3 stores per Account Manager ratio, ensuring adequate attention. South Africa-based team with global client base.
8	Andzen	Client Retention Rate: First Klaviyo Master Elite Partner in Asia-Pacific and 5th globally to achieve this status. Strong APAC market presence with growing client base. Case Study ROI: Cheeky Chickadee achieved 200% revenue growth over 2 years. Consistent engagement improvements across portfolio. Certifications: Klaviyo Master Elite Partner. Shopify Plus Partner Program member. 2025 K:Partners Award Winner (APAC). Third-Party Ratings: Best Design Agency in APAC 2023, Best Email Personalization 2024, Top 50 Most Rewarding Emerging Companies in Australia 2023. Breadth of Services: Email, SMS, Messenger marketing, lifecycle automation, customer journey mapping, and Shopify Plus integrations. Team Strength: Brisbane-based with global reach. Clients include Moana Bikini, SABO, Greenskin Wine, and World Fitness Australia. Strong for brands targeting APAC markets.
9	Lilo Social	Client Retention Rate: Serves 550+ DTC brands, indicating ability to maintain relationships at scale. Formerly known as Tequila Sunrise. Case Study ROI: Claims 963.76% average email revenue growth, 9.6x return in first 30 days, and 18x return after one year. These are aggressive claims that warrant verification during sales process. Certifications: Klaviyo Elite Partner status validates platform expertise and client results. Third-Party Ratings: 4.9/5 on Clutch with 40 reviews. Some mixed feedback in reviews indicates results don't always match claims. Due diligence recommended. Breadth of Services: Lifecycle marketing, email and SMS for DTC brands. Focused service set rather than full-service. Team Strength: Based in Jackson, WY, founded 2018. Notable clients include Obvi, Schoolyard Snacks, and Fat Snax. Pricing at $450-$500/email or $4,000-$7,000/month packages.
10	SmartMail	Client Retention Rate: Eight years in business with documented long-term client relationships. $187M total revenue generated for clients demonstrates sustained performance. Case Study ROI: Tools Today achieved 78x ROI on Klaviyo campaigns. Digital Supply saw 48x ROI. A women's apparel brand reported 540% increase in email revenue. Automated flows alone delivered up to 800% ROI. Certifications: Klaviyo Agency Partner with deep platform expertise built over 8+ years. Third-Party Ratings: Positive reviews across platforms. Has sent 11 billion emails and captured 163 million new subscribers for clients. Breadth of Services: Full-service email marketing, campaign management, Klaviyo flows and automations, list growth, segmentation, and SMS marketing. Team Strength: Established team with 8+ years experience. Notable clients include Esther & Co. and Ties.com. Accessible entry point starting at $500/month makes them viable for smaller brands.
11	Fuel Made	Client Retention Rate: 24 years in business since 2000, indicating strong long-term client relationships. Combines Shopify Plus development with email marketing for integrated engagements. Case Study ROI: BK Beauty achieved 118% lift in order placement rate. Turbie Twist saw 87% conversion bump. Results demonstrate CRO and email working together. Certifications: Shopify Plus agency and Klaviyo Professional Partner. Dual expertise in development and email is relatively rare. Third-Party Ratings: Positive reviews highlighting integrated approach. Long track record provides credibility. Breadth of Services: Email marketing, Shopify Plus development, and conversion rate optimization. Ideal for brands needing both CRO and email in one engagement. Team Strength: Based in Colbert, WA with 24 years experience. Smaller team focused on quality over volume.

Each of these agencies has demonstrated capability in ecommerce email marketing, though they bring different strengths. Whether you're a startup needing accessible pricing or an enterprise brand requiring complex ESP migrations, this list gives you vetted starting points. Consider your budget, current email revenue percentage, and how hands-on you want to be when making your choice.

• Why Email Marketing Matters for Ecommerce

  Email remains the highest-ROI channel for ecommerce brands. The benchmarks vary, but top performers generate 30-50% of total revenue from email and SMS combined. If you're below 20%, you're leaving money on the table.

  But ecommerce email is different from other email marketing. You need flows that trigger on behavior: abandoned carts, browse abandonment, post-purchase sequences, win-back campaigns, VIP segmentation. You need SMS integration that doesn't feel spammy. And you need creative that converts in crowded inboxes.

  Most general marketing agencies treat email as an afterthought. The agencies on this list treat it as a primary revenue driver because that's what it is for ecommerce brands.

• What I Look for in an Email Marketing Partner

  Not every agency knows how to move the needle for ecommerce brands. When I'm evaluating email marketing agencies to recommend, I'm looking for execution and proof.

  They need to show real ROI tied to email-attributed revenue, not just open rates or click rates. They should understand Klaviyo cold because that's where most ecommerce brands live. And they should treat transparency as standard. If you don't know what's happening in the campaign or how you're tracking against revenue goals, something's wrong.

  The best agencies ask the right questions: What percentage of revenue comes from email today? What's your average order value? Where are customers dropping off in the lifecycle? These questions reveal whether they understand ecommerce economics or just generic email marketing.

• Why Searchbloom Doesn't Offer Email Marketing

  We get asked about email marketing constantly. It's a natural complement to SEO and paid media for ecommerce brands. But we've made a deliberate choice not to offer it.

  Email marketing done right requires specialized expertise, dedicated tools, and teams that live in Klaviyo every day. We'd rather refer clients to specialists who can deliver exceptional results than try to bolt on a service that would be mediocre.

  That's why this list exists. After years of trial and error with referrals, I've identified the agencies I actually trust. One10 Media is at the top because they've earned it through results, communication, and the kind of execution that makes me comfortable putting my reputation on the line.

• Klaviyo Partner Tiers Explained

  Klaviyo's partner program has multiple tiers, and they matter when evaluating agencies. The tiers are based on client results, platform expertise, and revenue managed.

  Elite and Master Elite partners represent the top fraction of all Klaviyo agencies globally. They've demonstrated consistent results across multiple clients and have deep platform expertise. Platinum and Gold tiers are still strong but represent a larger pool of partners.

  When an agency claims Klaviyo partnership, ask which tier. It's a meaningful differentiator that's easy to verify.

Writer's note: Hi, Cody C. Jensen here. I'm writing this article based on my personal experience in the digital marketing industry for the last 17 years. This list is different from our usual content because Searchbloom doesn't offer email marketing. We focus on SEO and paid media. But clients constantly ask for email marketing recommendations, and after years of disappointing referrals, I finally have agencies I trust. One10 Media is #1 because they've earned it. They deliver results, communicate transparently, and treat clients like partners. When I send someone their way, I know they'll be taken care of. Enjoy!