USE-CASE GUIDE — AGENCIES
Best Email Platforms for Agencies in 2026
Multi-client account management, white-label reporting, API access, and partner programmes that actually pay.
Choosing a platform for an agency is a different calculation from choosing one for yourself. You are optimising for four things at once: how fast a new client can be onboarded, how little of your team's time each account consumes each month, whether reporting can go to a client without your vendor's logo all over it, and what the partner programme pays. A tool that is marginally better to use but has no agency tier can cost you more in admin than it saves in execution. The second issue is standardisation. Agencies that let every client pick their own ESP end up employing specialists in five platforms and re-learning quirks on every audit. The agencies with healthy margins usually recommend one primary platform, keep one alternative for a specific client type, and inherit the rest reluctantly. We judged these five on multi-client account structure, permissions and team seats, white-label and client-facing reporting, API and integration depth for custom work, and partner programme economics.
At a glance
| Tool | Best for | From | Free plan | Rating | Try |
|---|---|---|---|---|---|
| ActiveCampaignTop pick | Agencies standardising a client roster on one platform | From $15/mo (annual) | 14-day trial | 4.7 | Visit → |
| HubSpot | Agencies serving sales-led B2B clients | Free CRM · paid from $20/mo | 2,000 emails/mo with HubSpot branding | 4.4 | Visit → |
| Klaviyo | Agencies whose clients are Shopify and WooCommerce brands | $20/mo | Up to 250 contacts, 500 sends | 4.3 | Visit → |
| Brevo | Agencies managing lots of small local-business accounts | From $9/mo | Unlimited contacts, 300 emails/day | 4.3 | Visit → |
| Drip | Agencies that need juniors productive in days | Not yet verified | Free trial | Not yet rated | Visit → |
What we love · what we don't
What we love
- Partner programmes now pay recurring margin, not just referral bounties
- Multi-account consoles have improved on the two biggest platforms
- Send-based pricing makes small-account work viable again
What we don't
- True white-label reporting is still rare — most agencies rebuild decks by hand
- Client-facing seat and permission controls are weaker than agency work demands
- Per-contact pricing gets renegotiated with the client, not the vendor
The ranking
1. ActiveCampaign
ActiveCampaign has invested in agencies longer than most of the category. The partner programme gives you a single console over client accounts, migration support when you bring a client across, and margin on resale rather than a one-off referral fee. That last point matters: recurring partner economics change what a retainer is worth.
The platform itself is the other half of the argument. Whatever a client asks for — lead scoring, CRM pipelines, conditional lifecycle journeys, ecommerce flows — you can build it without telling them to change tools in a year. The cost is training: your team needs genuine fluency, and onboarding a junior takes weeks, not days.
Pros
- Mature partner programme with recurring margin
- Multi-account console and migration assistance
- Automation depth covers almost any client brief
- Strong API and webhooks for custom builds
Cons
- Steep team training curve
- Client bills rise with contacts and tiers
- Reporting needs work before it faces a client
Who it's for
Agencies with five or more retained email clients wanting one standard platform.
Skip it if
You manage many tiny accounts where per-account cost dominates.
2. HubSpot
HubSpot's Solutions Partner programme is the most developed agency channel in this category: tiering, co-marketing, directory listings, certifications, and inbound referrals that can become a genuine acquisition line. For agencies whose clients are B2B and sales-led, that channel plus the platform's attribution reporting is hard to beat.
The economics are less friendly to small accounts. Marketing tiers escalate quickly with marketing contacts, onboarding is a real project, and clients occasionally balk at the total cost of ownership. It works best when you are selling strategy alongside implementation rather than competing on retainer price.
Pros
- Best-developed partner programme and referral flow
- Attribution reporting clients understand
- One record across marketing, sales, and service
- Certification path for staff
Cons
- Expensive for small client accounts
- Heavy onboarding per client
- Automation depth trails ActiveCampaign
Who it's for
Agencies positioned around B2B revenue operations, not just campaign execution.
Skip it if
Your clients are small DTC brands on tight budgets.
3. Klaviyo
For an ecommerce agency, Klaviyo's per-flow revenue attribution is the commercial argument for your own existence. You can show a client exactly what the cart-recovery flow earned last month, which makes retainer renewals a conversation about numbers rather than deliverables. Its partner programme is well established in the Shopify ecosystem.
Client-side cost is the friction: Klaviyo gets expensive as lists grow, and you will spend part of every quarterly review defending the invoice. There is no white-label layer, so client-facing reports carry Klaviyo branding unless you rebuild them in your own template.
Pros
- Revenue attribution that proves retainer value
- Strong ecommerce partner ecosystem
- Deep segmentation on store data
Cons
- No white-label reporting
- Client cost rises steeply with list size
- Only makes sense for commerce clients
Who it's for
Ecommerce-specialist agencies and retention consultancies.
Skip it if
Your roster is B2B or service businesses.
4. Brevo
If you run email for twenty local businesses on modest retainers, per-contact pricing kills the model. Brevo's send-based pricing means an account with 12,000 stored contacts and one monthly campaign costs very little, which is exactly the shape of most small-business client work. Transactional email and SMS on the same account reduce the vendor count too.
You trade depth for economics. Segmentation and reporting are thinner than the platforms above, so sophisticated clients will eventually ask for something you cannot build here. Treat it as the volume tier of your practice, not the flagship.
Pros
- Send-based pricing suits low-volume client accounts
- Free tier for prototyping a client build
- Transactional email and SMS included
Cons
- No dedicated multi-account console
- Thinner reporting for client decks
- Automation depth limited
Who it's for
Agencies with a long tail of small accounts.
Skip it if
Your clients need advanced lifecycle automation.
5. Drip
Drip's simplicity is an agency argument as much as a client one: a junior can build a competent ecommerce flow in an afternoon rather than a fortnight. For shops where staff turnover is a real cost, that matters.
We have not completed a full BestSends hands-on cycle on Drip, so it is unscored here and we do not publish pricing we have not verified. There is also no dedicated agency console, so multi-client management is manual.
Pros
- Low training overhead
- Quick to first working automation
- Solid onsite forms
Cons
- Not yet scored by BestSends
- Pricing not yet verified by us
- No agency multi-account tooling
Who it's for
Small teams prioritising speed of delivery.
Skip it if
You need partner margin or a client console.
How we chose these platforms
Agency weighting: multi-client account structure, seats and permissions, client-facing and white-label reporting, API depth for custom builds, and partner programme economics including recurring margin.
Scores are BestSends platform scores from our standing test cycles. Platforms without a completed hands-on cycle appear unscored and with pricing marked unverified.
Best for...
Best for Agency standardising a roster
ActiveCampaign
One console, partner margin, no client outgrows it.
Best for B2B revops agency
HubSpot
Partner referrals plus attribution clients believe.
Best for Ecommerce retention shop
Klaviyo
Per-flow revenue proves the retainer every month.
Best for Long tail of small accounts
Brevo
Send-based pricing keeps thin retainers profitable.
Buying guide: budget, mid-market, enterprise
What we'd actually buy at each budget level, and why.
Under $30/mo per client
Brevo
Keeps small local-business accounts profitable when the retainer is a few hundred dollars.
$80–$400/mo per client
ActiveCampaign
The default standard: partner margin, multi-account console, automation depth that covers any brief.
$1,000/mo per client and up
HubSpot or Klaviyo
HubSpot for B2B revops engagements; Klaviyo for large DTC retention programmes.
Workflow example: onboarding a new client in the first ten days
A five-person agency taking on a DTC brand with 40,000 contacts on an inherited platform, a neglected list, and no automations worth keeping.
- 01
Days 1–2: audit before you migrate
Pull engagement by cohort, current deliverability, and every active automation. Half of what you inherit should not be rebuilt.
- 02
Day 3: authenticate the new sending domain
SPF, DKIM, and DMARC on a subdomain before a single send. This is the step agencies skip and then blame the platform for.
- 03
Days 4–5: import segmented, not wholesale
Bring engaged contacts first, park the dormant ones, and warm sending volume over two weeks instead of blasting 40,000 addresses on day one.
- 04
Day 6: rebuild the three flows that make money
Welcome, cart recovery, post-purchase. Nothing else until those are live and attributed.
- 05
Day 8: set the reporting standard
Agree the four numbers you will report monthly — revenue per recipient, flow revenue, list growth, deliverability — and template the deck once.
- 06
Day 10: hand over a permissions map
Client seats, your seats, and who can hit send. Write it down; it prevents the 9pm broadcast nobody approved.
The margin in agency email work comes from templating this sequence. Every account you onboard the same way costs you less than the one before it.
Pricing at every list size
Estimated monthly cost on each platform's standard plan, billed monthly. Cheapest at each tier highlighted.
| Tool | 1,000 | 10,000 | 50,000 | 100,000 |
|---|---|---|---|---|
| ActiveCampaign | From $15/mo | $79/mo | Priced by tier | Priced by tier |
| HubSpot | From $20/mo | Priced by tier | Priced by tier | Priced by tier |
| Klaviyo | $45/mo | $150/mo | Priced by tier | Priced by tier |
| Brevo | From $9/mo | From $9/mo | Send-based | Send-based |
| Drip | Not yet verified | Not yet verified | Not yet verified | Not yet verified |
Frequently asked questions
ActiveCampaign for most agencies: it has a mature partner programme with recurring margin, a multi-account console, migration help, and enough automation depth that clients do not outgrow it. Agencies serving B2B revops clients often standardise on HubSpot instead, and ecommerce specialists on Klaviyo.
Keep reading
Our top pick
ActiveCampaign leads our testing
Tested hands on against every platform in this guide, on real accounts and real campaigns.
Still deciding?
Put any two platforms head-to-head on price, automation, and deliverability.
Related reading
About the Author
Carlos Gil is the Editor in Chief of BestSends and the author of The End of Marketing. He has spent 15+ years in email marketing with in-house roles at LinkedIn, GetResponse, BMC Software, Winn-Dixie, and Save-A-Lot.
Read more about Carlos