Best Email Marketing Agencies for Ecommerce in 2026
By Pete Devkota·Last reviewed ·Editorial · no paid placements
The best email marketing agencies for ecommerce, on our ranking, are Flowium (New York) for US DTC brands that want a large retention-only team, Underground Ecom (London) for UK and international brands at scale, Chronos Agency (Singapore and Sydney) for repeat-purchase brands selling across APAC and the US, and Andzen (Brisbane) for Australian brands. InboxArmy fits brands on a platform other than Klaviyo, with a published floor of $1,500 a month.
Search "email marketing agency" and page one is directories, agency homepages, and listicles written by agencies that rank themselves first. This is one of those listicles. We're Email Optimize, a Klaviyo partner agency founded in 2017, and we sit at #5 below. What we're aiming for instead of a sales page: every entry gets a one-line best-fit profile, every claim comes from the agency's own site or Klaviyo's partner directory, and we tell you when someone else is the better hire.
The filter is ecommerce. A generalist email marketing agency that writes B2B nurture sequences and SaaS onboarding is playing a different sport from one that engineers abandoned cart, replenishment, and win-back flows for a Shopify store. Every agency here does ecommerce email and SMS as a core service, and the list deliberately mixes US, UK, and Australian operators, because that's where most brands reading this sell.
Receipts over adjectives. Where an agency publishes a number (team size, brands served, a pricing floor) we quote it and say where it came from. Where we couldn't verify something, we left it out. Last reviewed October 2026.
About the author. Aeronautical engineer turned ecommerce email specialist. Pete founded Email Optimize in 2017 and is behind $250M+ in attributed email and SMS revenue across 800+ brands. Full profile →
Growth agency; works in Klaviyo, Attentive or Postscript
Retention from $5,000/mo
Paid media and retention together
Credentials as stated in each entry below; Klaviyo tiers are as shown in Klaviyo's partner directory on 1 October 2026. Prices are only those the agency publishes on its own site (InboxArmy and Darkroom re-checked 10 October 2026); "Quote only" means it doesn't publish one.
Methodology
How we ranked these
Each agency is judged on five things: (1) ecommerce specialism, meaning email and SMS for online stores is a core service rather than a bolt-on, (2) named ecommerce clients on their own site or partner profile, (3) verifiable platform credentials, checked in Klaviyo's partner directory at connect.klaviyo.com where the agency lists there, (4) a clear engagement model (team structure, pricing approach, contract terms), and (5) a best-fit profile we can state in one sentence. We don't take paid placements or affiliate fees from anyone on this list.
Facts about each agency (location, partner tier, clients, published pricing) were checked against the agency's own website or public partner profile in October 2026. Tiers, team sizes and prices change, so re-check anything that matters to your decision before you sign. We left off agencies we couldn't verify and one-person operations (those live on our Klaviyo experts list). Two entries (#11 and #12) are deliberate exceptions to the specialist rule: agencies where email sits inside a broader Shopify or growth offering, included because a lot of brands genuinely want that shape.
The list
The 12 best email marketing agencies for ecommerce, ranked
Best for US DTC brands wanting a large, retention-only email and SMS team
Klaviyo Elite Master Partner (per Klaviyo partner directory) · New York, NY (distributed team)
Founded in New York in February 2017 by Andriy Boychuk, Flowium has grown into one of the biggest retention-only agencies in the market, reporting 1,000+ brands served. Email is the core, with SMS, push, WhatsApp, RCS and direct mail layered on. Their Klaviyo partner profile lists Elite Master tier and clients including True Classic, Dr. Squatch, RSVLTS and Last Crumb. Per their site, there are no long-term contracts and a two-year price lock. Strongest fit for US DTC brands that want a deep bench and a proven process more than a boutique relationship. The question to ask any agency at this scale: exactly who works your account, and how many other accounts they carry.
Elite Master tier in Klaviyo's partner directory
1,000+ brands served since 2017 (per their site)
Named clients: True Classic, Dr. Squatch, RSVLTS, Last Crumb
No long-term contracts, two-year price lock (per their site)
Best for UK brands at scale, and international DTC with a board-level retention budget
Klaviyo Elite Master Partner (per Klaviyo partner directory); Klaviyo EMEA Agency Partner of the Year 2025 · London, UK
London-headquartered, with a team of 100+ retention marketers per their site and a claim to be one of the largest Klaviyo partners in EMEA. Klaviyo's directory lists them at Elite Master, Klaviyo named them one of its three EMEA Agency Partners of the Year for 2025, and their partner profile lists clients including AG1, Virgin, Huda Beauty, Oh Polly, Chilly's and Osprey. The service menu runs from CRM audit and roadmap through creative, automations, SMS and WhatsApp. Strongest fit for UK brands looking for an email marketing agency with real scale, and for international brands where retention is already a board-level line item. For a brand doing a few million a year, an engagement built for AG1-sized programs is usually more machine than you need.
Elite Master tier (per Klaviyo directory); EMEA Agency Partner of the Year 2025
Best for repeat-purchase brands selling across APAC and the US
Klaviyo Elite Master Partner (per Klaviyo partner directory) · Singapore, with a Sydney office
Founded in 2017 by Joshua Chin, Chronos runs 80+ retention specialists out of Singapore and Sydney per their site, and reports 500+ brands served. They work across 11 platforms (Klaviyo, Attentive, Braze, Postscript, Omnisend and HubSpot among them) and cover email, SMS, push, WhatsApp, RCS and direct mail. The named client list leans Australian and consumable: The Oodie, Australian Furniture Warehouse, SkinnyMe Tea, Pupnaps, Truly Beauty. Strongest fit for brands whose lifetime value lives in reorder timing, and for brands selling across APAC and the US that want one team on both. If you're a single-market Klaviyo brand, the multi-platform breadth is capability you'll pay for and not use.
80+ retention specialists across Singapore and Sydney (per their site)
Elite Master in Klaviyo's partner directory, 4.9 on Clutch
Clients: The Oodie, Australian Furniture Warehouse, Truly Beauty
Works across 11 messaging platforms, not Klaviyo-only
Best for Australian brands wanting the most-credentialed local Klaviyo agency
Klaviyo Elite Master Partner, first in APAC (per their site) · South Brisbane, Australia
Andzen is the name most Australian brands hear first when they ask around for an email marketing agency, and the credentials back it up. Per their site, they were the first Klaviyo Elite Master partner in APAC (and fifth worldwide), were among the first Shopify Plus partners, and Klaviyo named them its APAC Partner of the Year in 2025 and again in 2026 (announced 9 September 2026). The service menu goes past email and SMS into loyalty and CRM consulting, with teams covering APAC, the Americas and EMEA. Clients include Hard Yakka, Rose-Hip Vital, Cheeky Chickadee, Aje and Janie and Jack. Strongest fit for Australian brands at scale where credentials matter to the board and the program is mostly AU-domestic.
First Klaviyo Elite Master partner in APAC (per their site)
Klaviyo APAC Partner of the Year, 2025 and 2026
Clients: Hard Yakka, Aje, Cheeky Chickadee, Janie and Jack
Email, SMS, loyalty and CRM consulting under one roof
Best for revenue-first ecommerce brands in AU and North America wanting senior operator depth
Klaviyo Partner · Adelaide, Australia
That's us. Founded in 2017 by Pete Devkota, an aeronautical engineer who treats an email program like an airframe: measure the forces, strip what doesn't fly. Klaviyo specialists and ecommerce-only (with Omnisend for brands it suits better), with $250M+ in attributed email and SMS revenue across 800+ brands. The receipts are named: Relaxium (INC 5000), where Pete served 22+ months as embedded Head of Retention Marketing and email and SMS added +$3M in incremental annual revenue; Popl (Y Combinator backed), where email and SMS went from under 20% to 50-60% of revenue over 21 months; Better Body Co., where email went from about 10% of revenue to the 20-25% target range after a three-month consulting engagement. Where we're not the pick: if you need one agency across Klaviyo, Braze and Salesforce, or if partner tier is a procurement checkbox, others on this list fit better.
$250M+ attributed email and SMS revenue across 800+ ecommerce brands
Official Klaviyo partner, ecommerce-only, founded 2017
Pete Devkota: embedded Head of Retention at Relaxium (INC 5000) for 22+ months
DORTA Method (Delivered → Opened → Read → Trusted → Acted) for diagnosis
Adelaide HQ with delivery in Australian and North American business hours
Sticky Digital positions itself as a retention marketing agency for Shopify brands, running full-service email and SMS plus retention strategy and conversion rate optimization. Their Klaviyo partner profile lists Platinum Master tier and a client list that skews beauty and wellness: U Beauty, r.e.m. beauty, Deborah Lippmann, Nest New York and MUD\WTR. Their site also shows PrettyLitter, Tubby Todd and American Optical, and says they were voted Retention Marketing Agency of the Year. Strongest fit for US beauty, wellness and lifestyle brands on Shopify that want a retention partner fluent in that category's creative and cadence.
Platinum Master tier in Klaviyo's partner directory
Client list skews beauty and wellness (U Beauty, r.e.m. beauty, MUD\WTR)
Email, SMS, retention strategy and CRO
Complimentary Klaviyo migrations advertised on their site
Best for brands that want flat-fee, unlimited-send retention without discount addiction
Klaviyo Platinum Master Partner (per Klaviyo partner directory; their site shows a Master Elite badge) · Greater Manchester, UK (also registered in Singapore)
UK-registered (Sale, Greater Manchester) with a Singapore entity, Magnet Monster reports 300+ ecommerce brands served over seven years. The commercial model is the distinctive part: per their site, you send unlimited emails, SMS, WhatsApp and direct mail for one flat monthly fee, which removes the incentive for an agency to pad the calendar or bill by the asset. Named clients include Outerknown, Waterdrop, Duradry, Bliss, Laura Geller and Spotlight Oral Care. Strongest fit for brand-led DTC that wants predictable cost and a retention program that doesn't lean on a constant discount cadence.
Flat monthly fee, unlimited sends across email, SMS, WhatsApp and direct mail (per their site)
Platinum Master in Klaviyo's directory; Master Elite badge on their site
Clients: Outerknown, Waterdrop, Duradry, Bliss, Laura Geller
Hustler's structural advantage is written into their operating model: per their site, account managers handle a maximum of three stores. That's the single most useful number to ask any agency for, and most won't give it to you. They report 450+ ecommerce brands served, $110M generated for clients in 2025, and 65% of clients staying two years or more. Klaviyo's directory lists them at Elite Master tier, with clients including BlendJet, TAO Clean, Tailored Athlete and VIM & VIGR. Beyond email and SMS they also offer UGC ad creative and HubSpot CRM work. Strongest fit for mid-market DTC where the in-house team is small and the agency needs to behave like part of it.
Account managers capped at three stores (per their site)
Elite Master tier in Klaviyo's partner directory
450+ ecommerce brands, $110M generated for clients in 2025 (per their site)
Clients: BlendJet, TAO Clean, Tailored Athlete, VIM & VIGR
Texas-based, operating since 2016, with 120+ email marketing specialists per their site. InboxArmy is platform-agnostic by design: they list 40+ email service providers, from Klaviyo and Omnisend through Salesforce Marketing Cloud, Braze, Iterable and HubSpot, plus SMS and push. They're also one of the few agencies that publish a floor: managed services start at $1,500 per month. Strongest fit for ecommerce brands on a non-Klaviyo platform, brands that need production capacity (templates, coding, campaign builds) more than strategy, and teams that want a lower entry price. If you're Klaviyo-native and want a Klaviyo specialist, the specialists above go deeper.
Managed services from $1,500/month (published on their site)
40+ ESPs supported, not Klaviyo-only
120+ specialists, operating since 2016 (per their site)
Best for brands that want done-for-you campaign production priced by output
Klaviyo Partner (per their site)
SmartMail sells done-for-you ecommerce email with a pricing model that breaks from the retainer norm: per their site, they only charge for what they produce. They report 150+ brands under management and $187M in revenue generated for clients, with case studies featuring apparel names like Wrangler, GAP, Nautica and Lee. They build on Klaviyo and other ESPs, including Mailchimp, Braze and Emarsys. Strongest fit for brands with an internal owner for strategy who need reliable, well-designed campaign and flow production without paying for a full retainer.
Pay-for-what-we-produce pricing instead of a traditional retainer (per their site)
Best for UK Shopify brands wanting email run by the same agency as the store
Shopify agency with a Klaviyo email and SMS service · London, UK (offices in New York and Manchester)
Charle is a Shopify-only agency first (design, development, migrations, CRO and SEO), with email and SMS marketing as one of its service lines. Per their site, they're based in London with offices in New York and Manchester, and the client list includes Cambridge Satchel, 111SKIN, Beauty Bay, Muc-Off and Vollebak. This is the exception to our specialist rule, and it earns its place for one reason: when the problem is half store and half email (broken tracking, a checkout that loses people before the flow can catch them), one team owning both removes a hand-off. If your store is healthy and you only need email, a specialist will go deeper.
Shopify-only agency with an email and SMS service line
London HQ, New York and Manchester offices (per their site)
Clients: Cambridge Satchel, 111SKIN, Beauty Bay, Muc-Off
Best when the store and the email program both need work
Best for funded DTC that wants email run alongside paid media and creative
Full-funnel growth agency (retention is one service line) · New York, with hubs in Lisbon and São Paulo
Darkroom is a growth agency, not an email specialist: paid media, performance creative, Amazon, web and AI search sit alongside retention marketing. We include it because a real share of brands searching for an email marketing agency actually want one partner across acquisition and retention, and Darkroom is open about pricing. Per their site, retention marketing starts at $5,000 per month, and they work inside your existing Klaviyo, Attentive or Postscript accounts. Named clients include Everlane, Olipop, Nécessaire and Crate & Barrel. Strongest fit for funded DTC brands where the email calendar needs to move in lockstep with paid spend and creative testing.
Retention marketing from $5,000/month (published on their site)
Works inside your existing Klaviyo, Attentive or Postscript accounts
Paid media, creative and retention under one agency
Practical decision
Which email marketing agency fits which brand
The best email marketing agency is the one built for your size, market and platform. Start your shortlist here.
US DTC wanting a large retention-only bench
→ Flowium. Scale, process, and no long-term contract per their site.
UK brand at scale, or international DTC with enterprise retention budgets
→ Underground Ecom. London HQ and one of Klaviyo's EMEA Agency Partners of the Year for 2025.
Australian brand, AU-domestic, where credentials matter to the board
→ Andzen.
Consumables brand selling across APAC and the US
→ Chronos Agency. Sydney and Singapore teams, replenishment-heavy client list.
AU brand expanding into North America, or a US brand wanting senior operator depth
→ Email Optimize. Adelaide HQ, AU and NA business hours, and a founder who has run retention inside an INC 5000 brand.
US beauty or wellness brand on Shopify
→ Sticky Digital.
Brand that wants predictable, flat-fee cost
→ Magnet Monster (flat monthly fee, unlimited sends) or SmartMail (pay for output).
Mid-market DTC with a small in-house team
→ Hustler Marketing. The three-store cap per account manager is the reason.
Brand on Salesforce, Braze, Iterable, or another non-Klaviyo ESP
→ InboxArmy. Platform-agnostic with a published $1,500/month floor.
UK Shopify brand where the store and email both need work
→ Charle.
Funded DTC wanting one partner for paid and retention
→ Darkroom.
How to choose
How to choose an email marketing agency
Most agency pitches are built on adjectives: strategic, data-driven, creative, full-service. None of that is checkable. Ask for things that are. A good ecommerce email marketing agency should be able to answer every question below in the first call without going vague.
Show me revenue per recipient, not open rates. Since Apple Mail Privacy Protection, opens are inflated and mostly noise. Ask what flow revenue per recipient and campaign revenue per recipient looked like before and after for a client like you.
Name three clients in my category. Replenishment brands, fashion drops and high-AOV considered purchases need different flow architecture. "We've worked with brands like yours" is not an answer.
Who works my account, and how many other accounts do they carry? This is the number that decides your outcome. Hustler Marketing publishes a three-store cap; most agencies won't say.
Which platform, and why? Klaviyo-only specialists go deeper on one tool. Platform-agnostic agencies are right if you're on Salesforce, Braze or Iterable. Neither is wrong, but know which you're buying.
What tier are you, really? If an agency leans on a Klaviyo tier, look it up at connect.klaviyo.com. It takes 30 seconds.
What happens in the first 30 days? Good agencies diagnose before they build: deliverability, flow coverage, segmentation, attribution settings. If the plan starts with a redesign of your template, keep looking.
What's the contract? Month-to-month after an initial term is common. Long lock-ins with no performance review are a yellow flag.
Fewer agencies publish prices than you'd hope, so here's what is public as of October 2026. InboxArmy lists managed services from $1,500 per month. Darkroom lists retention marketing from $5,000 per month. Magnet Monster charges one flat monthly fee for unlimited sends, and SmartMail charges only for the output it produces. Our own pricing page puts ecommerce retainers at roughly $3,000 to $12,000 USD per month and one-off projects (audits, setups, migrations, flow rebuilds) at roughly $3,000 to $15,000 USD.
What moves the number: whether SMS is included, how many campaigns a month you want, how many flows need building or rebuilding, list size, and whether you're paying for strategy or just production. Treat any quote as the start of a scope conversation, not a price tag. And measure it the only way that matters: incremental email and SMS revenue against the fee. A $3,000 retainer that adds nothing is the expensive option.
Email marketing agency vs freelancer vs in-house hire
Freelancer: right for one-off jobs (an audit, a welcome flow, a migration) and for stores under roughly $500K a year where an ongoing retainer is hard to justify. You're vetting one person, so the quality range is wide.
Agency: right when the work is ongoing and multi-disciplinary, meaning strategy, copy, design, build, deliverability and reporting every month. That usually starts making sense around $500K to $1M in annual revenue, and it's where a team beats a single freelancer on continuity.
In-house: right when email is a strategic channel at $10M+ revenue and you can afford a senior hire (a US email marketing manager averages about $80K a year in base salary per Built In's 2026 data, before benefits) plus the months it takes to find one. Plenty of brands at that size keep an agency alongside the hire for production and a second opinion. The worst version of any of the three is the one nobody measures.
The US is the deepest market, and the one where most agencies on this list do the bulk of their work. Flowium (New York), Sticky Digital, Hustler Marketing (Jackson, Wyoming), InboxArmy (Grapevine, Texas), SmartMail and Darkroom (New York) are US-headquartered or US-led. For scale, start with Flowium; for beauty and wellness on Shopify, Sticky Digital; for a capped account-manager load, Hustler; for a non-Klaviyo platform or a published $1,500-a-month floor, InboxArmy; for email run alongside paid media, Darkroom.
The compliance baseline is CAN-SPAM, plus state privacy laws like California's CCPA. The US calendar is Black Friday-heavy, so ask every agency how they staff November.
Underground Ecom and Charle are London-based, and Magnet Monster is registered in Greater Manchester. For UK brands at scale, Underground Ecom; for flat-fee pricing and brand-led retention, Magnet Monster; for Shopify brands that want the store and email under one agency, Charle.
UK GDPR and PECR set a stricter consent bar than the US, so an email marketing agency in the UK should be able to show you how consent is captured and recorded at every sign-up point, not just promise compliance. We work with UK brands from Adelaide, with UK mornings overlapping our afternoons and evenings, and we're upfront that a London-based agency is the simpler choice if you need live UK-afternoon cover.
Andzen (South Brisbane) is the long-standing local leader, Chronos runs a Sydney office, and we're headquartered in Adelaide. For Australian brands at scale, Andzen; for consumables selling across APAC and the US, Chronos; for Australian brands also selling into North America, us.
Australian brands need an agency that knows the Spam Act 2003, registers branded SMS sender IDs with the ACMA, and plans around Black Friday, Boxing Day and the June end of financial year rather than a US calendar. If you sell in Australia and North America, few agencies genuinely run both markets; that cross-Pacific coverage is our specific fit.
An ecommerce email marketing agency builds and runs the email and SMS systems that sell for you: automated flows (welcome, abandoned cart, browse abandonment, post-purchase, replenishment, win-back), weekly campaigns, list growth, segmentation, deliverability and revenue reporting. The good ones measure themselves on revenue per recipient and the share of store revenue email drives, not on open rates.
On our ranking: Flowium, Underground Ecom, Chronos Agency, Andzen, Email Optimize, Sticky Digital, Magnet Monster, Hustler Marketing, InboxArmy, SmartMail, Charle and Darkroom. The best one for you depends on market (US, UK or Australia), platform (Klaviyo or another ESP), size, and whether you want a specialist or email inside a broader growth agency. The "Which email marketing agency fits which brand" section above maps each profile to a pick.
"Email marketing company" can mean the software or the people who run it. For software, Klaviyo is the default for ecommerce brands on Shopify and similar platforms, and Omnisend is the closest lower-cost alternative. For agencies, our top picks are Flowium for US DTC at scale, Underground Ecom for UK and international brands, Chronos Agency for repeat-purchase brands across APAC and the US, and Andzen for Australian brands. Pick the platform first, then an agency that specialises in it.
Published figures as of October 2026: InboxArmy managed services from $1,500/month, Darkroom retention from $5,000/month, and Email Optimize retainers roughly $3,000 to $12,000 USD/month with one-off projects roughly $3,000 to $15,000 USD. Magnet Monster uses a flat monthly fee and SmartMail charges per output. Scope (SMS, campaign volume, flow builds, list size) moves the number more than the agency name does.
Yes. A generalist email agency often does B2B nurture, newsletters and SaaS onboarding. An ecommerce specialist works on purchase-triggered flows, product and browse events, replenishment timing, predicted lifetime value and store integrations like Shopify. The levers that move ecommerce revenue are different, so ask for named ecommerce clients before you hire.
For UK brands at scale, Underground Ecom (London, Elite Master in Klaviyo's directory and one of Klaviyo's three EMEA Agency Partners of the Year for 2025) is the strongest credentialed option on this list. Magnet Monster (Greater Manchester) fits brands that want flat-fee pricing, and Charle (London) fits Shopify brands that want the store and email under one agency. Whoever you pick, check how they handle UK GDPR and PECR consent.
Andzen (South Brisbane) is the most-credentialed local agency, named Klaviyo's APAC Partner of the Year in 2025 and 2026. Chronos Agency runs a Sydney office and fits consumables brands selling across APAC. Email Optimize (Adelaide) fits Australian brands expanding into North America or wanting senior operator depth. Our Best Klaviyo Agencies in Australia list goes deeper.
For US DTC wanting scale, Flowium. For beauty and wellness on Shopify, Sticky Digital. For a small in-house team that wants a capped account-manager load, Hustler Marketing. For non-Klaviyo platforms or a lower entry price, InboxArmy. For email alongside paid media, Darkroom. Our Best Klaviyo Agencies in the USA list covers more US options.
Freelancers fit one-off projects and stores under roughly $500K a year. Agencies fit ongoing work at $500K+ where strategy, copy, design, build and deliverability all need covering every month. Above $10M, a senior in-house hire becomes realistic, often with an agency alongside for production.
Because leaving ourselves off would hide a relevant option, and ranking ourselves #1 would make the list useless. We put ourselves at #5, told you where we fit (revenue-first ecommerce brands in Australia and North America that want senior operator depth) and where we don't (multi-ESP programs, or buyers who need a top partner tier on paper). We take no paid placements or affiliate fees from any agency listed.