ChatGPT answers, unedited

If you're running an agency with multiple client accounts, I’d separate the problem into two layers: email execution/automation and client-facing reporting. There isn't one platform that is equally strong at both.

My shortlist

Current agency-focused comparisons consistently highlight ActiveCampaign for automation/multi-account workflows, while AgencyAnalytics is specifically built around consolidating client reporting. US Tech Automations BestSends

What I'd actually build

For most agencies, I'd use:

ActiveCampaign + AgencyAnalytics

ActiveCampaign handles:

• Client newsletters
• Segmentation
• Welcome sequences
• Lead nurturing
• Behavioral automations
• Forms/lists
• Email performance

Then AgencyAnalytics becomes the client-facing reporting layer. It can pull email data alongside GA4, Google Ads, social, SEO, etc., and create branded/white-label dashboards and automated reports. AgencyAnalytics AgencyAnalytics

It also supports separate client dashboards, custom branding and agency-wide roll-up reporting, which is particularly useful once you're managing a meaningful number of accounts. AgencyAnalytics AgencyAnalytics

When I'd choose something else

HubSpot — If your clients need CRM + email + sales pipelines + marketing automation in one system. AgencyAnalytics can also pull HubSpot email metrics into client dashboards. AgencyAnalytics

Klaviyo — If most of your clients are ecommerce brands. I'd favor it when Shopify/customer behavior, product recommendations, revenue attribution and sophisticated ecommerce flows are central to the work.

Brevo — Worth considering if you're managing a large number of relatively small/local-business clients and keeping software costs tightly controlled.

Campaign Monitor — Particularly interesting if the agency's core service is newsletters rather than complex lifecycle automation. AgencyAnalytics can consolidate data from multiple Campaign Monitor accounts into centralized dashboards and provides white-label reporting. AgencyAnalytics

The key distinction

If by "centralize" you mean "I want one login where my team can manage 20 clients' email accounts", I'd lean toward ActiveCampaign/Campaign Monitor.

If you mean "I want one place where my team and clients can see every client's email + ads + website + SEO performance", I'd use AgencyAnalytics as the reporting hub, with the email platform underneath it.

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether they're mostly B2B, local businesses, or ecommerce, I can narrow this down to a specific stack and estimate the monthly cost.

For an agency managing multiple clients’ newsletters, email automations, and performance reporting, the “best” platform depends on whether you prioritise automation depth, white-label client management, or simple scalable reporting. These are the strongest options:

My shortlist by agency type

1. General marketing agency (5–50 clients)

Best all-round setup: Campaign Monitor + Looker Studio

• Client separation is clean.
• Easy for account managers to run newsletters.
• Reporting is client-friendly.
• Good if clients mainly need campaigns, automations, and monthly reports. Campaign Monitor

2. Lead generation / funnel agency

Best: ActiveCampaign

Use it when you build:

• welcome sequences
• lead nurturing
• sales follow-ups
• behaviour-triggered campaigns
• CRM-connected automations

It is usually the better choice when email automation itself is a paid deliverable. Hack'celeration

3. Full-service digital agency

Best: HubSpot

A good fit if clients expect:

• marketing dashboards
• CRM reporting
• attribution
• sales pipeline visibility
• customer lifecycle automation

4. Local business / SME agency model

Best: Brevo or Zoho Campaigns

If you manage 20–100 smaller accounts, pricing and operational simplicity matter more than advanced workflows. BestSends Zoho

A practical agency stack I’d consider

Email execution

• ActiveCampaign (complex automation clients)
• Campaign Monitor (newsletter-heavy clients)

Dashboards

• lookerstudio.google.com for client-facing reports
• analytics.google.com for website conversion tracking

Client management

• agencyanalytics.com or dashthis.com for automated monthly marketing reports

If I were choosing one platform for a typical agency:

• Mostly newsletters + multiple brands: Campaign Monitor
• High-value automation retainers: ActiveCampaign
• B2B growth agency: HubSpot
• Many small clients with tight margins: Brevo/Zoho Campaigns

A key question is whether your agency needs one master dashboard where you can switch between client accounts, or whether you mainly need one reporting layer pulling results from separate client tools—the answer changes the best choice.

If your agency needs to manage newsletters + automations + client reporting across several brands, I’d narrow the field to these:

🥇 My pick: ActiveCampaign + AgencyAnalytics

For the use case you described, I wouldn't necessarily force one platform to do everything.

Use ActiveCampaign for the actual email work—campaigns, newsletters, segmentation, journeys, lead nurturing and automations. Current agency-focused comparisons particularly favor it for multi-account management and automation depth. Hack'celeration BestSends

Then use AgencyAnalytics as the agency-wide reporting layer. It can pull email metrics from ActiveCampaign, Brevo, Campaign Monitor, HubSpot, MailerLite, Klaviyo and others, while also combining them with GA4, ads, SEO, social, etc. AgencyAnalytics AgencyAnalytics

That gives you a structure like:

Agency
→ Client A
→ Client B
→ Client C
→ Client D

Each client gets:

• Their own email account
• Newsletter templates/campaigns
• Automated sequences
• Segments/lists
• Performance dashboard
• Automated monthly report
• Agency-branded/white-label reporting

AgencyAnalytics specifically supports client-level dashboards, automated reports, custom permissions and white labeling. AgencyAnalytics AgencyAnalytics

When I'd choose something else

Choose HubSpot if your clients need CRM + email + sales pipeline + attribution in one ecosystem. It's considerably more powerful, but usually harder to justify if you're primarily an email/newsletter agency.

Choose Brevo if you have lots of smaller clients and keeping the software cost down is important. It's particularly attractive when clients don't need extremely sophisticated automation.

Choose Campaign Monitor if your agency's work is mostly newsletter production and campaign management, rather than complex lifecycle automation. A 2026 agency-focused comparison ranked it particularly highly for multi-client agencies. Hack'celeration

Choose HighLevel if you're actually selling a packaged marketing system to clients—CRM, forms, funnels, SMS, email automation, pipelines, etc.—rather than primarily managing email.

The important distinction

I'd think about your stack as two separate jobs:

1. Client execution: ActiveCampaign / Brevo / HubSpot
2. Agency intelligence: AgencyAnalytics

That's much more scalable than trying to make the email platform itself your agency reporting system. AgencyAnalytics can aggregate email plus other channels into the same client dashboard, including PPC, SEO, analytics, social and ecommerce data. AgencyAnalytics

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether each client needs their own separate email account, I can give you a specific recommended stack and estimated monthly cost.

If you mean an agency managing newsletters + automated email journeys + client-facing performance dashboards across multiple clients, I’d shortlist these:

My recommendation: ActiveCampaign + AgencyAnalytics

ActiveCampaign is probably the strongest single email platform for an agency. Its automation capabilities are substantially deeper than typical newsletter tools, and current agency-focused comparisons consistently put it near the top for multi-client management and automation. Hack'celeration BestSends

Then I'd pair it with AgencyAnalytics for the client-facing layer.

AgencyAnalytics can pull marketing data from 85+ integrations, create white-labeled dashboards, automate reports, and create roll-up views across clients. You can put your agency's logo/colors/domain on the reporting experience. AgencyAnalytics AgencyAnalytics AgencyAnalytics

So your stack becomes:

Your agency
→ ActiveCampaign
→ separate client accounts/workspaces
→ newsletters + sequences + segmentation + automations
→ AgencyAnalytics
→ branded client dashboard + automated monthly report

That's a particularly good architecture if email is the service you're selling, but clients also want to see things like Google Ads, GA4, SEO, social, etc. in the same report.

If you want ONE platform

I'd rank them:

1. ActiveCampaign — best balance of automation and agency scalability.
2. Campaign Monitor — excellent if the core service is newsletters/campaign production and you want strong multi-client workflows. A 2026 agency test specifically ranked it best for multi-client agencies. Hack'celeration
3. HubSpot — best if you're essentially becoming the client's CRM/marketing department rather than just their email agency.
4. Brevo — compelling if you're managing lots of smaller clients and keeping costs down.
5. Klaviyo — my choice when most clients are Shopify/e-commerce brands; less compelling as a general-purpose agency platform.

The important distinction

I wouldn't try to force email execution and client reporting into the same product.

For an agency, there are really two jobs:

• Execution: campaigns, templates, lists, segmentation, automations, deliverability → ActiveCampaign / Klaviyo / Campaign Monitor
• Client reporting: KPIs, cross-channel data, branded dashboards, scheduled reports → AgencyAnalytics

AgencyAnalytics specifically supports separate client dashboards and automated reports, including white-labeled URLs and sender addresses. help.agencyanalytics.com

If you tell me roughly how many clients you have (e.g. 5, 20, 50+) and whether they're mostly B2B, e-commerce, or local/service businesses, I can narrow this down to the best 2–3 options and compare approximate monthly cost.

AgencyAnalytics can pull marketing data from 85+ integrations, create white-labeled dashboards, automate reports, and create roll-up views across clients. You can put your agency's logo/colors/domain on the reporting experience. AgencyAnalytics AgencyAnalytics AgencyAnalytics

So your stack becomes:

Your agency
→ ActiveCampaign
→ separate client accounts/workspaces
→ newsletters + sequences + segmentation + automations
→ AgencyAnalytics
→ branded client dashboard + automated monthly report

That's a particularly good architecture if email is the service you're selling, but clients also want to see things like Google Ads, GA4, SEO, social, etc. in the same report.

If you want ONE platform

I'd rank them:

1. ActiveCampaign — best balance of automation and agency scalability.
2. Campaign Monitor — excellent if the core service is newsletters/campaign production and you want strong multi-client workflows. A 2026 agency test specifically ranked it best for multi-client agencies. Hack'celeration
3. HubSpot — best if you're essentially becoming the client's CRM/marketing department rather than just their email agency.
4. Brevo — compelling if you're managing lots of smaller clients and keeping costs down.
5. Klaviyo — my choice when most clients are Shopify/e-commerce brands; less compelling as a general-purpose agency platform.

The important distinction

I wouldn't try to force email execution and client reporting into the same product.

For an agency, there are really two jobs:

• Execution: campaigns, templates, lists, segmentation, automations, deliverability → ActiveCampaign / Klaviyo / Campaign Monitor
• Client reporting: KPIs, cross-channel data, branded dashboards, scheduled reports → AgencyAnalytics

AgencyAnalytics specifically supports separate client dashboards and automated reports, including white-labeled URLs and sender addresses.

For an agency managing multiple clients, the “best” platform usually isn’t the one with the most email features — it’s the one that handles:

• separate client workspaces/accounts
• reusable newsletter templates
• automation journeys
• approvals and permissions
• client-facing dashboards
• white-label reporting
• integrations with ads, CRM, analytics, and ecommerce

A strong shortlist:

Campaign Monitor Zoho## My picks by agency type

1. You run a typical marketing agency (10–100 clients)

Best stack:

• Email + automation: hubspot.com or activecampaign.com
• Dashboards: agencyanalytics.com or lookerstudio.google.com

This gives you a client portal/reporting layer instead of manually exporting screenshots every month.

2. You mostly create newsletters for clients

Choose:

• campaignmonitor.com

It is designed around agencies managing multiple brands, with client account management, permissions, templates, and reporting. Campaign Monitor

3. You sell “email automation as a service”

Choose:

• activecampaign.com

Good for:

• lead nurture
• onboarding sequences
• abandoned cart flows
• sales pipelines
• behavioral triggers

Hack'celeration### 4. You need a white-label client dashboard

Pair your email tool with:

• agencyanalytics.com
• dashthis.com
• whatagraph.com

These are often better than relying on each email platform’s built-in reporting because clients can see email + ads + SEO + social + web analytics together.

A practical “agency operating system” setup

For many agencies, I’d build:

Client management

• clickup.com or asana.com

Email + automation

• ActiveCampaign / HubSpot / Campaign Monitor

Reporting

• AgencyAnalytics or Looker Studio

Data connections

• zapier.com or make.com

This avoids forcing one platform to do everything.

If I were choosing for a growing agency:

• Under 10 clients: ActiveCampaign + Looker Studio
• 10–50 clients: HubSpot + AgencyAnalytics
• Newsletter production agency: Campaign Monitor
• Ecommerce clients: Klaviyo + reporting layer
• High-volume small clients: Brevo or Zoho Campaigns

The biggest deciding factor is whether your agency is selling newsletter production or marketing automation/results — the ideal platform is different.

If you’re an agency managing multiple client brands, I’d narrow the field to these:

My top recommendation: ActiveCampaign + AgencyAnalytics

ActiveCampaign is probably the closest match if you want one operational platform for newsletters + automations across many clients. It has campaign reporting, automation reporting, attribution, custom reports, and agency-specific positioning for managing a client portfolio. ActiveCampaign ActiveCampaign ActiveCampaign

activecampaign.com

Then I'd put AgencyAnalytics on top as the client-facing reporting/dashboard layer. It supports 85+ integrations, white-labeled dashboards, client portals, automated reports, and—particularly useful for an agency—roll-up dashboards across multiple clients. AgencyAnalytics AgencyAnalytics AgencyAnalytics

agencyanalytics.com

AgencyAnalytics specifically integrates with ActiveCampaign and can pull its email metrics into branded client dashboards/reports. ActiveCampaign AgencyAnalytics

If you want one platform rather than a stack

ActiveCampaign would be my pick.

You could structure it roughly as:

Agency
→ Client A
→ Client B
→ Client C
→ Client D

with each client having their own contacts, newsletters, automations, segments and reporting, while your team operates from the agency side.

The big advantage is that the actual marketing work and automation live in the same system as the email performance data. ActiveCampaign also supports reporting across campaigns and automations rather than just basic open/click statistics. ActiveCampaign

When I'd choose the others

• HubSpot — choose this if your agency also manages CRM, lead pipelines, websites, forms, sales automation and attribution. It's more powerful as a complete client marketing stack, but can become expensive/complex.
• Klaviyo — my choice if most of your clients are Shopify/ecommerce brands and revenue attribution, segmentation and sophisticated lifecycle flows are the priority.
• Brevo — attractive if you're managing lots of smaller clients and keeping software costs down is important.
• AgencyAnalytics + separate email platforms — best if your clients already use different systems (Klaviyo, Mailchimp, ActiveCampaign, Brevo, etc.) and you want one agency-wide performance dashboard without forcing everyone onto the same email platform. AgencyAnalytics supports email integrations including ActiveCampaign, Brevo, Campaign Monitor, Klaviyo, Mailchimp and others. AgencyAnalytics AgencyAnalytics Knowledge Base

What I'd build for an agency

If you're starting from scratch, I'd seriously consider:

ActiveCampaign → execution & automation
AgencyAnalytics → client dashboards & reporting
GA4 → website/conversion data
Shopify → ecommerce data where applicable

That gives you a clean separation between doing the marketing and proving the marketing worked.

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether they're mainly B2B, ecommerce, or local businesses, I can give you a much more specific recommendation—including the likely monthly software cost and the best agency/client-account structure.

If you want one platform rather than a stack

ActiveCampaign would be my pick.

You could structure it roughly as:

Agency
→ Client A
→ Client B
→ Client C
→ Client D

with each client having their own contacts, newsletters, automations, segments and reporting, while your team operates from the agency side.

The big advantage is that the actual marketing work and automation live in the same system as the email performance data. ActiveCampaign also supports reporting across campaigns and automations rather than just basic open/click statistics.

When I'd choose the others

If your goal is one agency operating layer for multiple clients—newsletters + automations + client-level performance dashboards—I’d shortlist these:

🥇 My recommendation: ActiveCampaign + AgencyAnalytics

Rather than forcing one tool to do everything, I'd use:

ActiveCampaign for the actual email operation:

• Campaign/newsletter creation
• Segmentation
• Automated journeys
• Lead nurturing
• CRM integration
• Client-by-client accounts

Recent agency-focused comparisons continue to rate ActiveCampaign highly for multi-account management and automation depth. BestSends BestSends

Then put AgencyAnalytics on top as your agency reporting layer. It supports 85+ integrations, including ActiveCampaign, Brevo, Campaign Monitor, Klaviyo, Mailchimp and others, and provides separate client dashboards, automated reports, permissions and white-labeling. AgencyAnalytics AgencyAnalytics

agencyanalytics.com

The resulting workflow is essentially:

Your agency
→ manages all client email accounts
→ builds newsletters/automations in ActiveCampaign
→ AgencyAnalytics pulls performance data
→ each client gets their own branded dashboard/report
→ you retain an agency-wide view of performance.

If most clients are e-commerce

I'd switch the recommendation to Klaviyo + AgencyAnalytics.

Klaviyo is particularly compelling if clients are on Shopify/e-commerce because its Portfolio functionality can manage multiple accounts and provide aggregate performance reporting across them. Klaviyo Academy

If you're looking for a single platform

I'd look hardest at Klaviyo or ActiveCampaign, depending on client type.

But if by "centralize" you mean "I want my team to log into one agency dashboard and see every client's email performance, while clients see their own branded dashboards", I would not try to make the email platform itself your reporting system.

ActiveCampaign + AgencyAnalytics is the stack I'd choose for a general-purpose email/marketing agency.

If you tell me roughly how many clients you manage (e.g. 10, 30, 100+) and whether they're mostly B2B or e-commerce, I can narrow this down to the best 2–3 options and estimate the monthly cost per client.

If you’re an agency managing email for multiple clients, I’d narrow the field to three approaches:

1. HighLevel — best if you want everything under one roof

gohighlevel.com

This is probably my #1 recommendation if your agency wants to centralize the whole client operation, not just newsletters.

You get separate client sub-accounts, email campaigns, automation, CRM, funnels, forms, SMS, etc. HighLevel's current agency plans are built explicitly around sub-accounts: Unlimited is $297/month with unlimited sub-accounts, while Agency Pro is $497/month and adds things like SaaS mode, automated sub-account creation and advanced API access. GoHighLevel GoHighLevel

It also has agency-level rolled-up reporting and scheduled reports for individual sub-accounts. HighLevel Support Portal HighLevel Support Portal

Choose it if: you're selling "email + CRM + automation + reporting" as a package.

2. ActiveCampaign + AgencyAnalytics — my choice for a sophisticated email agency

activecampaign.com + agencyanalytics.com

This is the combination I'd choose if email marketing itself is the core service.

ActiveCampaign is much stronger than most agency platforms for complex customer journeys, segmentation, behavioral automation and CRM. It explicitly supports agencies managing large numbers of client campaigns and identities. ActiveCampaign ActiveCampaign

Then use AgencyAnalytics as the client-facing reporting layer. It connects to 85+ marketing platforms, including ActiveCampaign, Mailchimp, Klaviyo and HubSpot, and provides custom dashboards, white-label reports, client portals and automated reporting. AgencyAnalytics AgencyAnalytics Knowledge Base

There's also a direct ActiveCampaign ↔ AgencyAnalytics integration specifically designed to automate dashboards and reports for clients. ActiveCampaign

Choose it if: you want excellent email execution and polished cross-channel client reporting.

3. Campaign Monitor — worth considering for high-volume client management

campaignmonitor.com

This is particularly interesting if your agency's workflow is:

Client A → newsletters + automations
Client B → newsletters + automations
Client C → newsletters + automations
...repeat for 20–100 clients.

Its agency-oriented account structure makes separating client brands/accounts particularly convenient. A recent 2026 agency comparison also ranked it strongest specifically for multi-client management. Hack'celeration

I'd pick it over HighLevel if you don't need CRM, SMS, funnels, sales pipelines, etc.

What I'd actually build

For a typical 10–50 client email agency, I'd lean toward:

ActiveCampaign → email/newsletters + automations

↓

AgencyAnalytics → centralized dashboards + client portals + automated reports

↓

Your agency → one internal view of every client

This gives you separation between doing the work and reporting the work, which tends to be more flexible than forcing everything into one platform.

AgencyAnalytics can also combine email performance with Google Ads, GA4, social, SEO, Shopify, etc., so the client dashboard can answer "Is marketing working?" rather than merely "How did our last newsletter perform?" AgencyAnalytics

My ranking for your specific use case

1. ActiveCampaign + AgencyAnalytics — best overall for a serious email marketing agency
2. HighLevel — best if you want an all-in-one agency SaaS/CRM platform
3. Campaign Monitor — best if managing lots of distinct client email accounts is the primary requirement
4. HubSpot — best for higher-ticket B2B clients where CRM/sales attribution matters
5. Brevo — attractive if you have lots of smaller clients and need to keep software costs down

One important distinction: if by "centralize" you mean one login where your team can jump between 30 clients, build campaigns, manage automations, and see every client's KPIs, I would evaluate HighLevel vs ActiveCampaign + AgencyAnalytics first. That's a substantially different requirement from simply finding the best newsletter platform.

gohighlevel.com

This is probably my #1 recommendation if your agency wants to centralize the whole client operation, not just newsletters.

You get separate client sub-accounts, email campaigns, automation, CRM, funnels, forms, SMS, etc. HighLevel's current agency plans are built explicitly around sub-accounts: Unlimited is $297/month with unlimited sub-accounts, while Agency Pro is $497/month and adds things like SaaS mode, automated sub-account creation and advanced API access. GoHighLevel GoHighLevel

It also has agency-level rolled-up reporting and scheduled reports for individual sub-accounts. HighLevel Support Portal HighLevel Support Portal

Choose it if: you're selling "email + CRM + automation + reporting" as a package.

2. ActiveCampaign + AgencyAnalytics — my choice for a sophisticated email agency

activecampaign.com + agencyanalytics.com

This is the combination I'd choose if email marketing itself is the core service.

ActiveCampaign is much stronger than most agency platforms for complex customer journeys, segmentation, behavioral automation and CRM. It explicitly supports agencies managing large numbers of client campaigns and identities. ActiveCampaign ActiveCampaign

Then use AgencyAnalytics as the client-facing reporting layer. It connects to 85+ marketing platforms, including ActiveCampaign, Mailchimp, Klaviyo and HubSpot, and provides custom dashboards, white-label reports, client portals and automated reporting. AgencyAnalytics AgencyAnalytics Knowledge Base

There's also a direct ActiveCampaign ↔ AgencyAnalytics integration specifically designed to automate dashboards and reports for clients. ActiveCampaign

Choose it if: you want excellent email execution and polished cross-channel client reporting.

3. Campaign Monitor — worth considering for high-volume client management

campaignmonitor.com

This is particularly interesting if your agency's workflow is:

Client A → newsletters + automations
Client B → newsletters + automations
Client C → newsletters + automations
...repeat for 20–100 clients.

Its agency-oriented account structure makes separating client brands/accounts particularly convenient. A recent 2026 agency comparison also ranked it strongest specifically for multi-client management. hackceleration.com

I'd pick it over HighLevel if you don't need CRM, SMS, funnels, sales pipelines, etc.

What I'd actually build

For a typical 10–50 client email agency, I'd lean toward:

ActiveCampaign → email/newsletters + automations

↓

AgencyAnalytics → centralized dashboards + client portals + automated reports

↓

Your agency → one internal view of every client

This gives you separation between doing the work and reporting the work, which tends to be more flexible than forcing everything into one platform.

For an agency managing multiple clients’ newsletters, email automations, and performance dashboards, the best choice depends on whether you prioritize client management, automation depth, or reporting/white-labeling.

Top agency-friendly options

Hack'celeration Zoho## My shortlist by agency type

1. You manage 5–50 client newsletters

Pick: Campaign Monitor

Best fit if your workflow is:

• Client A → monthly newsletter
• Client B → nurture sequence
• Client C → promotions
• Monthly reporting decks

It is built around agency needs like separate client accounts, permissions, templates, and reporting. Campaign Monitor

2. You sell “we build your lifecycle marketing”

Pick: ActiveCampaign

Best for:

• Welcome sequences
• Lead nurture
• Abandoned cart flows
• Sales follow-ups
• Behavioral automation

It is usually the strongest automation engine for agencies that charge for strategy and implementation. Hack'celeration

3. You want one operating system for clients

Pick: HighLevel

Good if your agency sells:

• CRM setup
• Funnels
• SMS/email campaigns
• Appointment booking
• Lead management

It feels more like an agency operating platform than an email platform.

4. You need polished client reporting

Pair your email platform with a dashboard tool:

• agencyanalytics.com — client reporting dashboards
• lookerstudio.google.com — flexible custom dashboards
• clicdata.com — cross-channel agency dashboards and automated reporting ClicData

A practical agency stack

For many small-to-mid agencies, I would structure it like this:

Email execution: Campaign Monitor or ActiveCampaign
→ Client dashboards: AgencyAnalytics or Looker Studio
→ Project management: ClickUp / Asana
→ Client approvals: built-in approvals or a workflow tool

Quick recommendation

• Creative/content agency: Campaign Monitor
• Marketing automation agency: ActiveCampaign
• Local business lead-gen agency: HighLevel
• B2B growth agency: HubSpot
• 10+ small clients with tight margins: Zoho Campaigns or Brevo

If you tell me roughly how many clients you manage (5, 20, 100+) and whether they are mostly B2B, ecommerce, or local businesses, I can narrow this to a specific stack.

If you mean an agency that manages newsletters + automated email journeys + client-facing reporting across multiple client accounts, I’d shortlist these:

My picks

1. HighLevel — best if you're a full-service agency

This is probably the strongest choice if you want each client to have a separate account/sub-account while your agency operates everything centrally. It goes beyond email into CRM, funnels, SMS, forms, pipelines, reporting, etc. Recent agency-focused comparisons also put it at the top for the combination of multi-client management and white-labeling. Tool Decision Engine

2. Campaign Monitor — best if email is the core service

I'd seriously consider this if you don't need a CRM/SMS/funnel platform. Campaign Monitor is particularly interesting for agencies because its agency setup is designed around separate client accounts, brand management and client reporting. A recent 2026 agency test specifically ranked it strongest for multi-client email management. Hack'celeration Campaign Monitor

3. ActiveCampaign — best for sophisticated automations

If your agency's value proposition is things like lead nurturing, behavioral sequences, sales automation and CRM integrations, ActiveCampaign is hard to beat. The tradeoff is that its multi-client/white-label experience isn't as elegant as purpose-built agency platforms. Hack'celeration BestSends

4. Brevo — best value

Worth looking at if you have lots of smaller clients and want to keep software costs down. It's less elegant for centralized agency management than HighLevel/Campaign Monitor, but the economics can make sense for smaller accounts. Hack'celeration

5. Klaviyo — best for ecommerce

If most of your clients are Shopify/ecommerce brands, I'd choose Klaviyo over a generic agency platform. Its segmentation, behavioral flows, ecommerce data and revenue attribution are the real differentiators.

One important distinction

I'd separate your requirements into two categories:

A. "I want one platform to run all clients."
→ HighLevel or Campaign Monitor

B. "I want a central performance dashboard pulling data from different email platforms."
→ Use an analytics layer such as ClicData alongside the email platforms. ClicData is specifically designed to consolidate client marketing data and create white-label agency dashboards. ClicData

There are also newer platforms explicitly built around the agency-as-the-ESP model, such as aledamail.com and transpond.io, which offer isolated client workspaces, centralized management, automation and white-label reporting. Aledamail Transpond

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether they're mostly B2B, local businesses, or ecommerce, I can narrow this to the 2–3 platforms I'd actually shortlist and compare their pricing.

If your goal is one agency workspace for multiple clients, covering newsletters + automations + client-facing performance dashboards, I’d shortlist these:

1. HighLevel — my pick for most agencies

gohighlevel.com

If you want to consolidate your agency stack, this is probably the first one I'd demo. HighLevel puts email marketing, CRM, workflows, funnels, SMS, calendars, payments, etc. into one platform, with separate client sub-accounts. GoHighLevel

It also supports scheduled performance reports to client sub-accounts, including daily/weekly/monthly reporting. HighLevel Support Portal

Choose it if: you're managing lead-gen/service-business clients and want your team to operate almost everything from one system.

Downside: it's a very broad platform. If your agency is specifically an elite email/CRM shop, ActiveCampaign or Klaviyo can be more sophisticated for certain use cases.

2. ActiveCampaign + AgencyAnalytics — best quality setup

activecampaign.com

agencyanalytics.com

This is the combination I'd choose if email marketing itself is the core service.

ActiveCampaign gives you sophisticated segmentation, journeys, lead scoring and automation. Then AgencyAnalytics becomes the client reporting layer. AgencyAnalytics supports ActiveCampaign and other email platforms and lets you build branded dashboards/reports alongside SEO, PPC, social, GA4, etc. ActiveCampaign AgencyAnalytics

This is particularly compelling if a client wants one dashboard showing:

Email → Google Ads → Meta → SEO → website → ecommerce

rather than an isolated email report.

AgencyAnalytics currently advertises 85+ integrations, including ActiveCampaign, Brevo, Campaign Monitor, Klaviyo and Mailchimp. AgencyAnalytics

3. Transpond — interesting if you want email agency-first

transpond.io

This one is worth looking at specifically because it's designed around the problem you're describing: multiple clients, campaigns, automations and reporting in one agency environment.

It advertises client-specific campaigns/templates, reusable automations and built-in white labeling for campaigns, reports and dashboards. Transpond

I'd put this on the shortlist if you don't need the huge CRM/funnel ecosystem of HighLevel.

4. Klaviyo + AgencyAnalytics — if your clients are ecommerce

klaviyo.com

For Shopify/DTC clients, I'd favor Klaviyo over the general-purpose platforms. Its strength is sophisticated customer segmentation, behavioral flows and revenue-oriented email/SMS automation.

Then use AgencyAnalytics for the agency-level/client-facing reporting layer.

The tradeoff is that you're running two systems rather than getting everything inside one platform.

My actual recommendation

I'd narrow it to three architectures:

• Want one platform and maximum agency consolidation → HighLevel
• Email/CRM is your core expertise → ActiveCampaign + AgencyAnalytics
• Mostly ecommerce/DTC → Klaviyo + AgencyAnalytics

One important distinction: AgencyAnalytics is primarily the reporting/dashboard layer, not the email execution platform. Its value is that it can pull email performance together with the rest of a client's marketing data. AgencyAnalytics Knowledge Base AgencyAnalytics

If you tell me roughly how many clients you manage (e.g. 10, 30, 100), whether they're mostly B2B/local businesses or ecommerce, and whether you need white-labeling, I can narrow this to the best 2–3 options and compare actual 2026 pricing per client.

It also supports scheduled performance reports to client sub-accounts, including daily/weekly/monthly reporting. HighLevel Support Portal

Choose it if: you're managing lead-gen/service-business clients and want your team to operate almost everything from one system.

Downside: it's a very broad platform. If your agency is specifically an elite email/CRM shop, ActiveCampaign or Klaviyo can be more sophisticated for certain use cases.

2. ActiveCampaign + AgencyAnalytics — best quality setup

activecampaign.com

agencyanalytics.com

This is the combination I'd choose if email marketing itself is the core service.

ActiveCampaign gives you sophisticated segmentation, journeys, lead scoring and automation. Then AgencyAnalytics becomes the client reporting layer. AgencyAnalytics supports ActiveCampaign and other email platforms and lets you build branded dashboards/reports alongside SEO, PPC, social, GA4, etc. ActiveCampaign AgencyAnalytics

This is particularly compelling if a client wants one dashboard showing:

Email → Google Ads → Meta → SEO → website → ecommerce

rather than an isolated email report.

AgencyAnalytics currently advertises 85+ integrations, including ActiveCampaign, Brevo, Campaign Monitor, Klaviyo and Mailchimp. AgencyAnalytics

3. Transpond — interesting if you want email agency-first

transpond.io

This one is worth looking at specifically because it's designed around the problem you're describing: multiple clients, campaigns, automations and reporting in one agency environment.

It advertises client-specific campaigns/templates, reusable automations and built-in white labeling for campaigns, reports and dashboards. transpond.io

I'd put this on the shortlist if you don't need the huge CRM/funnel ecosystem of HighLevel.

4. Klaviyo + AgencyAnalytics — if your clients are ecommerce

klaviyo.com

For Shopify/DTC clients, I'd favor Klaviyo over the general-purpose platforms. Its strength is sophisticated customer segmentation, behavioral flows and revenue-oriented email/SMS automation.

Then use AgencyAnalytics for the agency-level/client-facing reporting layer.

The tradeoff is that you're running two systems rather than getting everything inside one platform.

My actual recommendation

I'd narrow it to three architectures:

If you mean an agency operating email newsletters + automated journeys for multiple clients, I’d narrow the field considerably. The key distinction is whether you want an agency operating system or simply a great email platform.

My shortlist

Recent agency-focused comparisons similarly put HighLevel toward the top for all-in-one agency management, ActiveCampaign for advanced automation, Klaviyo for ecommerce, and Campaign Monitor for multi-client newsletter management. Tool Decision Engine Hack'celeration

🥇 Best overall: HighLevel

gohighlevel.com

I'd choose HighLevel if your goal is:

• One agency login
• Separate client accounts/subaccounts
• Email newsletters
• Automated sequences
• CRM/pipelines
• Forms and landing pages
• SMS
• Client-facing dashboards
• White-labeling
• Reporting

It is particularly compelling if you're selling "we manage your marketing" rather than simply "we send your newsletters."

The downside: it can feel like a lot of software if all you really need is excellent email marketing. Its email experience isn't as specialized as Klaviyo or ActiveCampaign.

🥈 Best for serious email automation: ActiveCampaign

activecampaign.com

If email is the core service you're selling, I'd seriously consider ActiveCampaign.

It's excellent for:

• Welcome sequences
• Lead nurturing
• Behavioral automation
• Lead scoring
• Segmentation
• CRM-triggered emails
• Complex branching workflows
• Integrations

Its automation depth is one of the strongest options for agencies. Hack'celeration BestSends

The catch is that its agency/multi-client experience isn't as elegant as an agency-first platform, so you'll likely have more account-management overhead.

🥉 Best for newsletter agencies: Campaign Monitor

campaignmonitor.com

This is the one I'd investigate if your agency is primarily:

"We create and manage beautiful newsletters for 10–50+ businesses."

Campaign Monitor has particularly strong agency-oriented account management, allowing agencies to manage separate client accounts from a central setup. One recent agency-focused test specifically ranked it #1 for multi-client agency use. Hack'celeration

It's less compelling if you're building elaborate lifecycle/CRM automation.

🛒 If most clients are Shopify: Klaviyo

klaviyo.com

If your clients are ecommerce brands, I'd move Klaviyo to #1.

Its strengths are:

• Shopify/ecommerce integrations
• Customer segmentation
• Abandoned cart
• Post-purchase flows
• Product recommendations
• Revenue attribution
• Sophisticated behavioral automation

For an ecommerce retention agency, the depth of Klaviyo generally matters more than having a perfect agency dashboard.

🏢 If clients are B2B: HubSpot

hubspot.com

HubSpot makes sense when you're managing B2B clients where email is connected to sales.

You get CRM → marketing automation → sales pipeline → reporting in one ecosystem.

But I wouldn't use it simply to run newsletters for a bunch of SMB clients. It's generally too much platform for that job.

What I'd choose

If I were building an agency today:

• Local SMB / full-service marketing agency → HighLevel
• Email-specialist agency → ActiveCampaign
• Newsletter/content agency → Campaign Monitor
• Ecommerce agency → Klaviyo
• B2B demand-gen agency → HubSpot
• Lots of low-budget/small clients → Brevo

One important consideration: don't confuse "multiple accounts" with "one centralized dashboard." A lot of ESPs let you access multiple client accounts, but still leave you jumping between accounts and assembling reports manually. For an agency, I'd prioritize client isolation + account switching + client-level reporting + white-labeling + reusable templates/automations over raw email features. The Digital Project Manager Sasanova

If you tell me roughly how many clients you have (e.g. 5, 20, 100), whether they're mostly B2B/local/ecommerce, and whether clients need to log in, I can narrow this to the best 2–3 platforms and compare their actual agency pricing/architecture.

But I wouldn't use it simply to run newsletters for a bunch of SMB clients. It's generally too much platform for that job.

What I'd choose

If I were building an agency today:

• Local SMB / full-service marketing agency → HighLevel
• Email-specialist agency → ActiveCampaign
• Newsletter/content agency → Campaign Monitor
• Ecommerce agency → Klaviyo
• B2B demand-gen agency → HubSpot
• Lots of low-budget/small clients → Brevo

One important consideration: don't confuse "multiple accounts" with "one centralized dashboard." A lot of ESPs let you access multiple client accounts, but still leave you jumping between accounts and assembling reports manually. For an agency, I'd prioritize client isolation + account switching + client-level reporting + white-labeling + reusable templates/automations over raw email features.

If you mean one agency operating email marketing for multiple client businesses—newsletters + automated journeys + client-level reporting/dashboarding—I’d shortlist these:

🥇 My pick: Campaign Monitor

For the exact use case you described, Campaign Monitor is probably the cleanest fit.

Its agency offering is explicitly designed around separate client accounts, centralized management, client permissions, white-labeling, campaigns, automations, templates and reporting. Campaign Monitor

That matters because you don't really want one giant email database with 15 clients mixed together. You want:

• Client A → subscribers, templates, automations, reports
• Client B → completely separate
• Client C → completely separate
• Your agency → ability to switch/manage them centrally
• Client → restricted access to their own account
• Agency → consistent templates and processes across everyone

Campaign Monitor specifically advertises this multi-account setup and agency-branded/white-label client experience. Campaign Monitor

campaignmonitor.com

🥈 HighLevel if you're more than an email agency

HighLevel is more compelling if email is just one component of what you deliver.

You get the broader agency architecture: client subaccounts, CRM, funnels, SMS, forms, automation and reporting. Several 2026 agency comparisons put it at or near the top for this broader use case. Tool Decision Engine EmailSendX

The tradeoff is that it's less elegant as a pure email/newsletter platform. If your service is primarily "we manage your email marketing," I'd lean Campaign Monitor. If it's "we manage your whole marketing stack," I'd lean HighLevel.

🥉 ActiveCampaign if automation is the product

ActiveCampaign is the one I'd investigate if your agency sells sophisticated lifecycle automation.

Think:

lead → welcome → segmentation → behavior trigger → nurture → sales handoff → re-engagement

Its automation capabilities are substantially deeper than what I'd choose a basic newsletter platform for, and it has an established agency/partner ecosystem. Hack'celeration Sequenzy

The downside is that the agency/multi-client experience isn't as clean as the automation experience.

If you have lots of ecommerce clients

Go Klaviyo.

If most of your clients are Shopify/ecommerce brands, I'd actually put Klaviyo above Campaign Monitor because segmentation, flows, behavioral triggers and revenue attribution become much more important than having the prettiest agency management layer. Current agency comparisons similarly identify it as the strongest choice for ecommerce-heavy rosters. US Tech Automations Tool Decision Engine

One important distinction

I'd separate "email platform" from "agency performance dashboard."

If by dashboard you mean a client can log in and see something like:

Acme Co. — September
8 campaigns sent
142k emails delivered
42.1% open rate
3.8% CTR
$18,420 attributed revenue
+23% vs. previous month

…then I'd consider using an agency reporting layer on top of the email platforms, rather than choosing an ESP solely for its reporting.

That becomes particularly useful if you eventually have 20–50 clients using different ESPs.

My recommendation by agency type:

• Mostly newsletters + lifecycle email: Campaign Monitor
• Email + CRM + SMS + funnels: HighLevel
• Complex B2B/lead-nurture automation: ActiveCampaign
• Shopify/ecommerce: Klaviyo
• Many small clients / price sensitive: Brevo
• Enterprise B2B clients already using CRM: HubSpot

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether they're mostly B2B, local businesses, SaaS, or ecommerce, I can narrow this down to the best 2–3 and compare actual agency pricing + client dashboards + white-labeling + automation limits.

HighLevel is more compelling if email is just one component of what you deliver.

You get the broader agency architecture: client subaccounts, CRM, funnels, SMS, forms, automation and reporting. Several 2026 agency comparisons put it at or near the top for this broader use case. Tool Decision Engine EmailSendX

The tradeoff is that it's less elegant as a pure email/newsletter platform. If your service is primarily "we manage your email marketing," I'd lean Campaign Monitor. If it's "we manage your whole marketing stack," I'd lean HighLevel.

🥉 ActiveCampaign if automation is the product

ActiveCampaign is the one I'd investigate if your agency sells sophisticated lifecycle automation.

Think:

lead → welcome → segmentation → behavior trigger → nurture → sales handoff → re-engagement

Its automation capabilities are substantially deeper than what I'd choose a basic newsletter platform for, and it has an established agency/partner ecosystem. Hack'celeration Sequenzy

The downside is that the agency/multi-client experience isn't as clean as the automation experience.

If you have lots of ecommerce clients

Go Klaviyo.

If most of your clients are Shopify/ecommerce brands, I'd actually put Klaviyo above Campaign Monitor because segmentation, flows, behavioral triggers and revenue attribution become much more important than having the prettiest agency management layer. Current agency comparisons similarly identify it as the strongest choice for ecommerce-heavy rosters. ustechautomations.com Tool Decision Engine

One important distinction

I'd separate "email platform" from "agency performance dashboard."

If by dashboard you mean a client can log in and see something like:

Acme Co. — September
8 campaigns sent
142k emails delivered
42.1% open rate
3.8% CTR
$18,420 attributed revenue
+23% vs. previous month

…then I'd consider using an agency reporting layer on top of the email platforms, rather than choosing an ESP solely for its reporting.

If you’re an agency managing multiple client brands, I’d separate the problem into two layers: email execution/automation and agency-wide reporting.

My shortlist

🥇 Best overall: HighLevel

If your goal is one agency login → multiple clients → newsletters → automations → reporting, I'd look at HighLevel first.

Its agency model is built around separate client sub-accounts, and it now supports agency-level reporting plus scheduled reports to individual sub-accounts. HighLevel Support Portal HighLevel Support Portal HighLevel Support Portal

The big advantage is that you're not just reporting on email—you can tie email to leads, forms, appointments, conversations, deals, SMS, etc. That's particularly compelling if your clients hire you for lead generation rather than simply newsletters.

Choose it if: you want to consolidate a bunch of your agency stack.

Downside: it's a considerably bigger/more complex system than a dedicated email platform.

🥈 Best email + reporting combination: ActiveCampaign + AgencyAnalytics

For an agency where email strategy and automation are the core service, I'd seriously consider this combination.

agencyanalytics.com can pull ActiveCampaign data into client dashboards, alongside Google Analytics, Ads, social, SEO, etc. It supports 85+ marketing integrations and specifically supports client accounts, permissions, automated reports and white-label dashboards. AgencyAnalytics AgencyAnalytics AgencyAnalytics

So your architecture becomes:

ActiveCampaign
→ newsletters
→ segmentation
→ journeys/automations
→ lead nurturing

AgencyAnalytics
→ client dashboard
→ email performance
→ GA4
→ paid ads
→ SEO
→ social
→ automated monthly report

That's probably the cleanest professional agency setup if you don't need an all-in-one CRM.

🥉 Best if newsletters are the main product: Campaign Monitor + AgencyAnalytics

Campaign Monitor is particularly interesting for agencies because of its multi-client orientation. A recent agency-focused comparison found it strongest for agencies managing multiple client brands, while ActiveCampaign scored better for automation-heavy work. Hack'celeration

Then AgencyAnalytics handles the reporting layer; it supports Campaign Monitor as an email integration. AgencyAnalytics

I'd choose this if your service is essentially:

"We manage your newsletters, email campaigns and reporting."

rather than:

"We build your entire marketing automation/CRM system."

What I'd pick

If I were building an agency today:

• Lead-gen / full-service agency: HighLevel
• Email marketing agency: ActiveCampaign + AgencyAnalytics
• Newsletter/content agency: Campaign Monitor + AgencyAnalytics
• Enterprise clients: HubSpot + AgencyAnalytics
• Lots of small clients / cost-sensitive: Brevo + AgencyAnalytics

One important point: AgencyAnalytics isn't really an email-sending platform. It's the reporting/client-dashboard layer. Its email integrations pull campaign data from platforms such as ActiveCampaign, Brevo, Campaign Monitor, HubSpot, Mailchimp, Klaviyo, etc. AgencyAnalytics AgencyAnalytics

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether you're mostly doing newsletters or sophisticated automations, I can narrow this to the best 2 options and compare their actual agency pricing/workflow.

Its agency model is built around separate client sub-accounts, and it now supports agency-level reporting plus scheduled reports to individual sub-accounts. HighLevel Support Portal HighLevel Support Portal HighLevel Support Portal

The big advantage is that you're not just reporting on email—you can tie email to leads, forms, appointments, conversations, deals, SMS, etc. That's particularly compelling if your clients hire you for lead generation rather than simply newsletters.

Choose it if: you want to consolidate a bunch of your agency stack.

Downside: it's a considerably bigger/more complex system than a dedicated email platform.

🥈 Best email + reporting combination: ActiveCampaign + AgencyAnalytics

For an agency where email strategy and automation are the core service, I'd seriously consider this combination.

agencyanalytics.com can pull ActiveCampaign data into client dashboards, alongside Google Analytics, Ads, social, SEO, etc. It supports 85+ marketing integrations and specifically supports client accounts, permissions, automated reports and white-label dashboards. AgencyAnalytics AgencyAnalytics AgencyAnalytics

So your architecture becomes:

ActiveCampaign
→ newsletters
→ segmentation
→ journeys/automations
→ lead nurturing

AgencyAnalytics
→ client dashboard
→ email performance
→ GA4
→ paid ads
→ SEO
→ social
→ automated monthly report

That's probably the cleanest professional agency setup if you don't need an all-in-one CRM.

🥉 Best if newsletters are the main product: Campaign Monitor + AgencyAnalytics

Campaign Monitor is particularly interesting for agencies because of its multi-client orientation. A recent agency-focused comparison found it strongest for agencies managing multiple client brands, while ActiveCampaign scored better for automation-heavy work. hackceleration.com

Then AgencyAnalytics handles the reporting layer; it supports Campaign Monitor as an email integration.

I'd choose this if your service is essentially:

"We manage your newsletters, email campaigns and reporting."

rather than:

"We build your entire marketing automation/CRM system."

What I'd pick

If I were building an agency today:

If you're an agency managing multiple client brands, I’d separate the decision into two layers: the email/automation platform and the client-facing reporting layer. There isn't one tool that is truly best at both.

My shortlist

Recent agency-focused comparisons similarly put Campaign Monitor toward the top for multi-client management and ActiveCampaign toward the top for automation. Hack'celeration Campaign Monitor

🏆 What I'd choose for most agencies

ActiveCampaign + AgencyAnalytics

This is probably the strongest setup if your agency does sophisticated lifecycle marketing for several different clients.

• ActiveCampaign handles newsletters, segmentation, journeys, lead nurturing, behavioral triggers, CRM, etc.
• AgencyAnalytics pulls the performance data into branded client dashboards.
• AgencyAnalytics supports 85+ integrations and specifically supports email platforms including ActiveCampaign, Klaviyo, HubSpot and Mailchimp. AgencyAnalytics ActiveCampaign
• You can give each client a white-labeled dashboard, including your agency branding, colors, custom domain and client-specific permissions. AgencyAnalytics
• You can also have an agency-level view across clients, rather than logging into each client's email account individually. AgencyAnalytics

The downside is that it's two systems, rather than one.

If you really want one email platform

I'd look hardest at Campaign Monitor.

It's particularly interesting for agencies because its agency tooling is designed around managing multiple client accounts, with centralized management, client permissions, templates and reporting. Campaign Monitor

I'd choose it over ActiveCampaign if your clients mostly need:

newsletter → campaign → basic automation → reporting

rather than:

lead capture → segmentation → behavioral triggers → complex nurture → CRM → sales automation.

If most of your clients are ecommerce

Go Klaviyo + AgencyAnalytics.

Klaviyo is considerably stronger when the email program depends on ecommerce behavior—purchases, products viewed, abandoned carts, customer segments, repeat purchases, etc. AgencyAnalytics can then turn that data into the broader client-facing reporting environment.

The architecture I'd recommend

For a serious agency, I'd actually build the stack like this:

Client 1 → ActiveCampaign
Client 2 → ActiveCampaign
Client 3 → Klaviyo
Client 4 → ActiveCampaign
↓
AgencyAnalytics
↓
One branded agency dashboard / client portal

That gives you freedom to use the best ESP for each client while keeping the reporting experience consistent. AgencyAnalytics explicitly supports combining email data with SEO, paid media, social, ecommerce and CRM data in the same client report. AgencyAnalytics AgencyAnalytics

My ranking for your exact description:

1. 🥇 ActiveCampaign + AgencyAnalytics — best overall agency stack
2. 🥈 Campaign Monitor — best if you want email + agency management in one ecosystem
3. 🥉 Klaviyo + AgencyAnalytics — best for ecommerce-heavy client rosters
4. HubSpot + AgencyAnalytics — best for high-value B2B clients where CRM matters
5. Brevo — best if keeping the per-client cost low is a major priority

If you tell me roughly how many clients you manage, average contacts per client, and whether they're mostly B2B, ecommerce, or local businesses, I can narrow this to the best 2–3 platforms and estimate the monthly agency cost.

It's particularly interesting for agencies because its agency tooling is designed around managing multiple client accounts, with centralized management, client permissions, templates and reporting. Campaign Monitor

I'd choose it over ActiveCampaign if your clients mostly need:

newsletter → campaign → basic automation → reporting

rather than:

lead capture → segmentation → behavioral triggers → complex nurture → CRM → sales automation.

If most of your clients are ecommerce

Go Klaviyo + AgencyAnalytics.

Klaviyo is considerably stronger when the email program depends on ecommerce behavior—purchases, products viewed, abandoned carts, customer segments, repeat purchases, etc. AgencyAnalytics can then turn that data into the broader client-facing reporting environment.

The architecture I'd recommend

For a serious agency, I'd actually build the stack like this:

Client 1 → ActiveCampaign
Client 2 → ActiveCampaign
Client 3 → Klaviyo
Client 4 → ActiveCampaign
↓
AgencyAnalytics
↓
One branded agency dashboard / client portal

That gives you freedom to use the best ESP for each client while keeping the reporting experience consistent. AgencyAnalytics explicitly supports combining email data with SEO, paid media, social, ecommerce and CRM data in the same client report.

My ranking for your exact description:

If your goal is one operating system for an agency managing newsletters + email automations + client reporting across many accounts, I’d shortlist these:

*AgencyAnalytics is primarily the reporting/dashboard layer, rather than the platform I'd use to actually build email campaigns.

My strongest recommendation: ActiveCampaign + AgencyAnalytics

For a typical marketing agency, this is probably the sweet spot.

ActiveCampaign handles the actual email operation: newsletters, lists/segments, sequences, lead nurturing, automations, etc. Its Partner Portal is specifically designed to let agencies/resellers manage multiple client accounts. ActiveCampaign Help Center

Then use AgencyAnalytics as the agency's reporting layer. It can pull email metrics from ActiveCampaign and other platforms into branded client dashboards, and it supports multi-client/portfolio rollups. ActiveCampaign AgencyAnalytics

That gives you something like:

Client A
→ ActiveCampaign account
→ newsletters + automations
→ GA4 / Ads / CRM
→ AgencyAnalytics client dashboard

Client B
→ ActiveCampaign account
→ newsletters + automations
→ GA4 / Ads / CRM
→ AgencyAnalytics client dashboard

And internally:

AgencyAnalytics agency dashboard
→ Client A
→ Client B
→ Client C
→ Client D
→ aggregate KPIs / comparisons / trends

AgencyAnalytics specifically supports 85+ integrations, white-label dashboards, client access, automated reports, and agency-level rollups. AgencyAnalytics AgencyAnalytics

If most of your clients are ecommerce

I'd seriously consider Klaviyo instead.

Klaviyo has a Portfolio feature designed for managing multiple accounts, including cloning assets between accounts and portfolio-level reporting/comparison. Klaviyo Academy

So for an agency doing Shopify/ecommerce email, I'd rank:

1. Klaviyo + AgencyAnalytics
2. Klaviyo alone
3. ActiveCampaign + AgencyAnalytics

Klaviyo is particularly compelling if you're managing lots of sophisticated flows—welcome, abandoned cart, post-purchase, winback, VIP, product-specific segmentation, etc.

If you want one platform rather than a stack

Then I'd look hardest at HubSpot.

It's much broader than an email platform: CRM + marketing automation + email + sales + reporting. Its dashboards can combine marketing, sales, revenue and service data, with granular permissions. HubSpot

The downside is cost and complexity. For an agency primarily delivering email marketing, HubSpot can be overkill.

The architecture I'd choose

If I were building an agency today, I'd separate campaign execution from client reporting:

Email/automation layer

• Ecommerce → Klaviyo
• SMB/B2B/service businesses → ActiveCampaign
• Full CRM + marketing agency → HubSpot

Reporting layer

• AgencyAnalytics

This is better than trying to force one application to do everything. AgencyAnalytics' email dashboard can already consolidate metrics from Klaviyo, HubSpot, ActiveCampaign, Mailchimp and other platforms, so clients can get a consistent reporting experience even when your underlying email platform differs. AgencyAnalytics

agencyanalytics.com
activecampaign.com
klaviyo.com
hubspot.com

If you tell me roughly how many clients you manage (e.g. 10, 50, 200) and whether they're mostly ecommerce or B2B/local businesses, I can narrow this down to the best 2–3 setups and compare their approximate costs.

And internally:

AgencyAnalytics agency dashboard
→ Client A
→ Client B
→ Client C
→ Client D
→ aggregate KPIs / comparisons / trends

AgencyAnalytics specifically supports 85+ integrations, white-label dashboards, client access, automated reports, and agency-level rollups.

If most of your clients are ecommerce

I'd seriously consider Klaviyo instead.

Klaviyo has a Portfolio feature designed for managing multiple accounts, including cloning assets between accounts and portfolio-level reporting/comparison.

If your goal is one operating system for an agency managing newsletters + automations + client reporting across multiple accounts, I’d narrow it to four options.

My shortlist

1. Campaign Monitor — my pick for an email agency

This is probably the closest match to what you described.

Campaign Monitor explicitly supports separate client accounts under an agency setup, with separate lists, campaigns, templates, analytics and sending settings. It also supports agency/private-label branding and automated customer journeys. Campaign Monitor

The big advantage is that it doesn't try to make you adopt a giant CRM just to manage email.

I'd choose it if you:

• Manage 5–50+ client brands
• Primarily sell newsletters, email strategy and lifecycle automation
• Want clean separation between clients
• Need your team to jump between accounts easily
• Want client-friendly reporting without building everything yourself

A 2026 agency-focused comparison also ranked Campaign Monitor highest specifically for multi-client agency management. Hack'celeration

campaignmonitor.com

2. HighLevel — best agency operating system

If you're not just an email agency, I'd seriously consider HighLevel.

It gives you client subaccounts plus CRM, email, SMS, funnels, forms, calendars and automations in the same ecosystem. That's particularly compelling if your agency wants to sell "lead generation + nurture + conversion" rather than simply "email marketing."

The tradeoff is that the email experience isn't as elegant or specialized as some dedicated email platforms. Tool Decision Engine Cipion Marketing

It's particularly attractive if your clients are:

• Local businesses
• Professional services
• Home services
• Agencies/franchises
• Lead-generation businesses

And if you need sophisticated client reporting, AgencyAnalytics can pull HighLevel data into white-labeled dashboards. AgencyAnalytics

gohighlevel.com

3. ActiveCampaign — best for complex automations

If the automation engine is the most important part, I'd put ActiveCampaign near the top.

It's excellent for things like:

lead enters list → segment based on behavior → send nurture → wait → check engagement → branch → notify sales → move CRM stage → re-engage

That's where it tends to beat simpler newsletter-oriented platforms.

The downside for an agency is that multi-client administration isn't as elegant as platforms designed around the agency model. Current agency comparisons generally put it ahead for automation depth but behind Campaign Monitor/HighLevel for multi-account management. Hack'celeration Tool Decision Engine

activecampaign.com

4. Transpond — worth looking at

This one is particularly interesting given your exact wording.

Transpond positions itself specifically around agencies managing multiple clients, with campaigns, automations and reporting in one place, plus CRM synchronization and built-in white labeling. Transpond

It may be worth testing alongside Campaign Monitor if you're looking for something that feels agency-native rather than a business email platform adapted for agencies.

transpond.io

One important distinction

I would not necessarily force newsletters, automation, and reporting into the same software.

A potentially better agency stack is:

Campaign Monitor / ActiveCampaign
→ email campaigns + automations

AgencyAnalytics
→ centralized client performance dashboards

AgencyAnalytics can consolidate email data from platforms including Klaviyo, HubSpot, ActiveCampaign and Mailchimp, and create customizable/white-labeled client dashboards. AgencyAnalytics

That gives you something like:

Agency HQ → Client A / Client B / Client C → email + automation data → one standardized reporting dashboard

This is especially attractive if your clients use different email platforms.

agencyanalytics.com

What I'd choose

If you're primarily an email/newsletter agency:
→ Campaign Monitor + AgencyAnalytics

If you're a full-service marketing agency:
→ HighLevel

If sophisticated behavioral automation is your competitive advantage:
→ ActiveCampaign + AgencyAnalytics

If you want to investigate a purpose-built agency email platform:
→ Transpond

One caveat: I would evaluate client isolation, permissions, white-labeling, reusable templates/automations, approval workflows, and pricing as you add clients before committing. Those details make a huge difference at 10–30 clients, even when two platforms look similar on the feature checklist. The Digital Project Manager

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether they're mostly B2B, local businesses, or ecommerce, I can narrow this to the best 2–3 and compare actual agency pricing/economics.

If you’re an agency managing newsletters + automations + reporting for multiple clients, I’d shortlist these:

My recommendation

For a traditional marketing agency: I'd start with Campaign Monitor. Its agency offering specifically supports separate client accounts, centralized account management, templates, automations, permissions, and client-level reporting. It also has private-label options for an agency-branded client experience. Campaign Monitor

campaignmonitor.com

For an agency selling sophisticated lifecycle automation: choose ActiveCampaign. Its automation engine and CRM are substantially deeper, but you'll generally deal with separate client accounts rather than a beautifully unified agency dashboard. Hack'celeration

For a full-service agency that wants one client-facing operating system: HighLevel is probably the strongest option. It's broader than email—CRM, funnels, SMS, automation, reporting, and white-label client accounts—which can be valuable if email is only one part of your retainer.

For true white-label + many brands: take a serious look at BigMailer. Current agency-focused comparisons highlight unlimited client sub-accounts, centralized management, and white-labeling as core features. Mailfence Blog The Digital Project Manager

The key distinction

I'd choose based on what you're actually selling:

• “We manage your newsletters and email program” → Campaign Monitor
• “We build sophisticated lead/customer journeys” → ActiveCampaign
• “We run your entire marketing stack” → HighLevel
• “We need our own branded platform for 20+ clients” → BigMailer
• “Our clients are mostly Shopify/ecommerce” → Klaviyo
• “We need inexpensive email/SMS across lots of smaller clients” → Brevo

One important thing: don't optimize just for the email editor. For an agency, the biggest productivity gain comes from client isolation + account switching + permissions + reusable templates + automated reporting. Those are precisely the areas where agency-specific platforms differ from ordinary newsletter tools. Hack'celeration The Digital Project Manager

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether they're mostly B2B or ecommerce, I can narrow this to the best 2–3 platforms and compare actual 2026 pricing/cost per client.

For an agency selling sophisticated lifecycle automation: choose ActiveCampaign. Its automation engine and CRM are substantially deeper, but you'll generally deal with separate client accounts rather than a beautifully unified agency dashboard. hackceleration.com

For a full-service agency that wants one client-facing operating system: HighLevel is probably the strongest option. It's broader than email—CRM, funnels, SMS, automation, reporting, and white-label client accounts—which can be valuable if email is only one part of your retainer.

For true white-label + many brands: take a serious look at BigMailer. Current agency-focused comparisons highlight unlimited client sub-accounts, centralized management, and white-labeling as core features.

The key distinction

I'd choose based on what you're actually selling:

For an agency managing multiple clients, the “best” platform depends on whether you want to centralize email execution, automation, client reporting, or all three. Most agencies end up with either an all-in-one agency platform or a best-of-breed stack.

Here are the strongest options:

My recommended agency setups

1. Best overall stack for a marketing agency

HubSpot + AgencyAnalytics

Use:

• HubSpot → email newsletters, workflows, CRM, lead nurturing
• AgencyAnalytics → client-facing performance dashboards

Best if you sell retainers and need clients to see ongoing ROI.

2. Best value for 5–50 clients

Zoho Campaigns Agency Edition + Zoho Analytics

Good fit if you want:

• one agency login
• multiple client accounts
• reusable templates
• automated reports
• lower software costs

Zoho specifically positions its agency offering around multi-client management, permissions, template reuse, and reporting dashboards. Zoho Zoho

3. Best for an email-first agency

ActiveCampaign

Choose this if your deliverable is:

• nurture sequences
• onboarding flows
• lead scoring
• sales automation
• lifecycle campaigns

It is usually stronger than newsletter-first tools when clients pay you for revenue automation rather than just sending emails. Hack'celeration

4. Best for white-label client reporting

Pair:

• Email platform (ActiveCampaign, HubSpot, Klaviyo, etc.)
• Dashboard layer (AgencyAnalytics, Zoho Analytics, Databox)

This avoids forcing one tool to do everything.

Features I would prioritize before choosing

For an agency, look for:

• Separate client workspaces/accounts (avoid mixing client data)
• Reusable templates
• Approval workflows
• White-label dashboards
• Automated monthly reports
• Role permissions
• Client billing separation
• API/integration support

Shortlist by agency type

• Small boutique agency (1–10 clients): Zoho Campaigns, Brevo, ActiveCampaign
• Lifecycle/email automation agency: ActiveCampaign or HubSpot
• E-commerce agency: Klaviyo + reporting tool
• Full-service marketing agency: HubSpot + AgencyAnalytics
• White-label agency: Zoho stack, AgencyAnalytics, or a dedicated agency platform

If I were building a new agency stack today, I’d likely choose:

• ActiveCampaign + AgencyAnalytics for performance marketing/lifecycle clients
• HubSpot + AgencyAnalytics for higher-ticket B2B clients
• Zoho Campaigns + Zoho Analytics for maximizing margins across many smaller clients

Zoho Zite

If you’re an agency managing multiple client brands and want newsletters + automations + reporting in one operational layer, I’d narrow the field to HighLevel, Campaign Monitor, ActiveCampaign, and Brevo.

My shortlist

My pick for most agencies: HighLevel. It is the strongest if you want each client to live in its own account/sub-account while your agency maintains centralized control over campaigns, automations, CRM, reporting and other marketing functions. Current agency-focused comparisons also put it at the top for multi-client management and white-labeling. Tool Decision Engine

If you're specifically an email/newsletter agency, I'd look very seriously at Campaign Monitor. Its agency-oriented setup is particularly good for keeping multiple client brands/accounts separated while managing them from a central login. One recent 2026 hands-on comparison rated it the strongest option specifically for multi-client agencies. Hack'celeration

ActiveCampaign is the one I'd choose when the automation itself is the product you're selling—complex nurture sequences, lead scoring, CRM-triggered journeys, etc. Its automation capabilities are stronger than Campaign Monitor's, but its agency account structure isn't as clean. Hack'celeration Sequenzy

Brevo is worth considering if you have lots of smaller clients and margins matter. Its pay-per-send economics can work particularly well for clients with relatively small or infrequently mailed lists, although native multi-client management is weaker. Hack'celeration

One important distinction

If by "performance dashboards" you mean a dashboard clients can log into and see campaign KPIs, rather than just email-platform analytics, I'd actually consider a two-layer setup:

Email platform → reporting/dashboard platform

That lets you standardize the client-facing reporting across Mailchimp/ActiveCampaign/Klaviyo/etc., rather than forcing your agency to change platforms whenever a client's underlying email system changes.

There are also purpose-built agency platforms such as Transpond, which specifically combines campaigns, automations, reporting, client accounts and built-in white-labeling. Transpond

What I'd choose by agency type

• General digital/marketing agency: HighLevel
• Email/newsletter specialist agency: Campaign Monitor
• Lifecycle/CRM automation agency: ActiveCampaign
• E-commerce agency: Klaviyo
• Many small-budget clients: Brevo
• Want your agency branding everywhere: HighLevel or Transpond
• Need polished client performance reports across many marketing channels: Email platform + dedicated reporting layer

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether they're mostly B2B, local businesses, or e-commerce, I can narrow this to the best 2–3 and compare actual agency pricing, client-account limits, white-labeling, dashboards, and automation capabilities.

My pick for most agencies: HighLevel. It is the strongest if you want each client to live in its own account/sub-account while your agency maintains centralized control over campaigns, automations, CRM, reporting and other marketing functions. Current agency-focused comparisons also put it at the top for multi-client management and white-labeling. Tool Decision Engine

If you're specifically an email/newsletter agency, I'd look very seriously at Campaign Monitor. Its agency-oriented setup is particularly good for keeping multiple client brands/accounts separated while managing them from a central login. One recent 2026 hands-on comparison rated it the strongest option specifically for multi-client agencies. Hack'celeration

ActiveCampaign is the one I'd choose when the automation itself is the product you're selling—complex nurture sequences, lead scoring, CRM-triggered journeys, etc. Its automation capabilities are stronger than Campaign Monitor's, but its agency account structure isn't as clean. Hack'celeration Sequenzy

Brevo is worth considering if you have lots of smaller clients and margins matter. Its pay-per-send economics can work particularly well for clients with relatively small or infrequently mailed lists, although native multi-client management is weaker. Hack'celeration

One important distinction

If by "performance dashboards" you mean a dashboard clients can log into and see campaign KPIs, rather than just email-platform analytics, I'd actually consider a two-layer setup:

Email platform → reporting/dashboard platform

That lets you standardize the client-facing reporting across Mailchimp/ActiveCampaign/Klaviyo/etc., rather than forcing your agency to change platforms whenever a client's underlying email system changes.

There are also purpose-built agency platforms such as Transpond, which specifically combines campaigns, automations, reporting, client accounts and built-in white-labeling.

What I'd choose by agency type

For an agency managing multiple client newsletters, email automations, and performance dashboards, the best setup is usually not one tool for everything. The strongest stacks separate:

1. Email execution + automation
2. Client reporting + dashboards
3. Agency/client management

Here are the strongest options by agency use case:

For dashboards/client reporting:

My recommended agency stacks

Small agency (5–15 clients)

• Campaign Monitor or ActiveCampaign for newsletters + automations
• AgencyAnalytics for client dashboards
• Zapier or Make for connecting systems

Growth agency (15–50 clients)

• ActiveCampaign for automation
• AgencyAnalytics or Databox for reporting
• CRM integration (HubSpot, Salesforce, etc.)

Full-service marketing agency

• HubSpot as the central client marketing platform
• ActiveCampaign/Klaviyo where deeper email automation is needed
• AgencyAnalytics for client-facing reporting

A few things I would prioritize when choosing:

• Separate client workspaces/accounts (avoid mixing lists)
• White-label reports
• Client approval workflows
• Reusable automation templates
• Role-based access
• API/integration support
• Ability to clone campaigns between clients

If the agency mainly does newsletter production for clients (content calendars, approvals, sends), I’d lean toward Campaign Monitor + AgencyAnalytics. If the agency sells lead generation and lifecycle automation, I’d lean toward ActiveCampaign + AgencyAnalytics. Hack'celeration Campaign Monitor

If you’re an agency managing multiple clients’ newsletters + automated email journeys + client-facing performance reporting, I’d narrow the field to five platforms rather than looking at generic email tools.

My shortlist

1. HighLevel — best overall for an agency

If your goal is “one place where my agency can run every client's marketing”, this is probably where I'd start.

It gives you client/sub-account separation, email, SMS, CRM, forms, funnels, workflows, reporting and white-label capabilities in one ecosystem. Recent agency-focused comparisons consistently put it at or near the top for this exact use case. tooldecisionengine.com

Choose it if: you're selling an ongoing marketing service rather than merely sending newsletters.

Downside: its email/newsletter experience isn't as refined as the best email-specialist platforms.

HighLevel

2. ActiveCampaign — best if email automation is the core service

This would be my choice if your agency does things like:

• Welcome sequences
• Lead nurturing
• Re-engagement
• Behavioral automations
• Lead scoring
• CRM-triggered campaigns
• Complex segmentation

Its automation capabilities are still one of its biggest advantages, and it has an agency/reseller ecosystem. www.emailtooltester.comwww.campaignmonitor.com

The important caveat: reporting/client dashboards aren't its strongest agency feature. A common agency stack is ActiveCampaign + a dedicated reporting platform such as AgencyAnalytics. ActiveCampaign specifically integrates with AgencyAnalytics for automated, white-labeled client dashboards. www.activecampaign.com

ActiveCampaign

3. Campaign Monitor — best if you're essentially an outsourced email department

This is particularly interesting if your workflow is:

Client A → newsletter + automations + reporting
Client B → newsletter + automations + reporting
Client C → newsletter + automations + reporting
...repeat 20 times.

Campaign Monitor has been specifically designed around agency/multi-client use, with centralized client management, white-label reporting and template controls. www.campaignmonitor.com

I'd favor this over HighLevel if your clients don't need CRM, funnels, SMS, lead pipelines, etc.

Campaign Monitor

4. Klaviyo — best for ecommerce

If most of your clients are Shopify/ecommerce brands, I'd stop looking and evaluate Klaviyo first.

Its strength is connecting email to actual customer/ecommerce behavior:

Viewed product → abandoned cart → purchased → repeat purchase → VIP → win-back, etc.

It also has excellent revenue attribution and segmentation. The tradeoff is that it's less of a generic agency operating system than HighLevel. www.emailtooltester.comtooldecisionengine.com

Klaviyo

5. Brevo — best value

I'd look at Brevo if you're managing lots of smaller clients where margins matter.

It combines email, automation, SMS and CRM features at relatively accessible pricing. The big caveat is that its true white-label capabilities are more restricted than some agency-oriented alternatives. www.emailtooltester.comtooldecisionengine.com

Brevo

What I'd actually build

For a typical 5–30 client marketing agency, I'd consider two architectures:

Option A — simplest

HighLevel → newsletters + automations + CRM + client accounts + reporting

Best if you want to consolidate your stack.

Option B — best email/reporting combination

ActiveCampaign → email + automation
AgencyAnalytics → client dashboards + cross-channel reporting

AgencyAnalytics can pull ActiveCampaign metrics into white-labeled dashboards alongside things like SEO, PPC and social data, which is particularly useful if email is only one component of your agency's monthly reporting. www.activecampaign.com

One important distinction

If by “centralize” you mean “I want my team to log into one system, switch between 20 client accounts, send campaigns, manage automations, and give each client their own dashboard”, I'd prioritize HighLevel or Campaign Monitor.

If you mean “I want the absolute best email automation engine and don't mind having a separate reporting layer”, I'd choose ActiveCampaign + AgencyAnalytics.

If you tell me roughly how many clients you manage, whether they're mostly B2B/local businesses/ecommerce, and whether clients need to log in themselves, I can narrow this to the best 2–3 options and compare their actual agency pricing/cost at your scale.

For an agency managing multiple clients’ newsletters, email automations, and performance dashboards, the best setup is usually not one tool but a small stack:

1. Email execution platform (campaigns + automations)
2. Client reporting/dashboard layer (white-labeled performance views)
3. CRM/data connectors (optional, depending on clients)

Here are the strongest options by agency type:

Best dashboard/reporting companions

For client-facing dashboards, I would usually pair the email tool with:

• AgencyAnalytics — best if you need branded client portals combining email, SEO, PPC, social, and analytics data. Zite
• Databox — better for KPI dashboards and executive-style reporting. AgencyPro
• Looker Studio — good low-cost option if your team is comfortable building dashboards manually.

My shortlist by agency model

If you run a marketing agency with 10–100 clients

Recommended stack:

• HighLevel for client accounts + automations
• AgencyAnalytics for reporting

Good fit if you sell “marketing systems” rather than just newsletters. Tool Decision Engine

If you run an email retention/newsletter agency

Recommended stack:

• Campaign Monitor or ActiveCampaign
• AgencyAnalytics or Databox

Good fit for recurring newsletters, nurture sequences, lead magnets, and lifecycle campaigns. Campaign Monitor Zite

If most clients are Shopify/ecommerce brands

Recommended stack:

• Klaviyo
• Databox or AgencyAnalytics

Klaviyo’s strength is revenue-driven flows (welcome, abandoned cart, post-purchase, win-back). The Open Rate Club

If clients need a simple “see everything” portal

Look for:

• white-label dashboards
• separate client workspaces
• scheduled reports
• permissions
• automated monthly summaries

A practical agency stack I’d choose

For a small-to-mid agency:

Client operations
→ HighLevel

Advanced email automation
→ ActiveCampaign (for complex clients) or Klaviyo (for ecommerce)

Reporting
→ AgencyAnalytics

Internal workflow
→ ClickUp or Asana

That gives you:

• one place to manage clients
• repeatable automation templates
• branded dashboards
• less manual reporting

If you tell me your agency type (B2B, ecommerce, local businesses, creators, SaaS, etc.) and approximate client count, I can narrow this to a 2–3 tool stack.

Reporting
→ AgencyAnalytics

Internal workflow
→ ClickUp or Asana

That gives you:

If you’re managing multiple clients’ newsletters + automations + reporting, I’d prioritize a platform with true multi-client account management, not just a good email editor.

My shortlist for an agency

1. 🥇 Campaign Monitor — my pick for a newsletter-focused agency

This is probably the closest match to what you're describing. Campaign Monitor explicitly supports agencies managing separate client accounts, campaigns, automations, templates, billing, permissions and reporting from one platform. It also has private-label/white-label capabilities. www.campaignmonitor.comwww.sasanova.com

Campaign Monitor for Agencies

I'd choose it if: your core service is "we manage email marketing for 5–50 clients" rather than broader CRM/lead-gen services.

2. 🥈 ActiveCampaign — best if automation is the differentiator

If your clients need sophisticated journeys—lead nurturing, behavioral branching, sales pipelines, tagging, scoring, CRM integration, etc.—I'd lean toward ActiveCampaign.

Its automation capabilities are substantially deeper than what you need for simple newsletters, and agency-oriented account management is available. www.campaignmonitor.comwww.sasanova.com

ActiveCampaign

I'd choose it if: you're selling marketing automation rather than primarily newsletter production.

3. 🥉 HighLevel — best if you want to consolidate the whole agency stack

HighLevel becomes interesting if "email" is only part of what you do. It can give each client their own environment while your agency manages everything centrally, including CRM, funnels, automation and communications.

The tradeoff is that it's a much bigger system than an email platform—you may find it unnecessarily complicated if you're purely an email agency.

HighLevel

4. Klaviyo — best for ecommerce

If most of your clients are Shopify/ecommerce brands, I'd put Klaviyo near the top. Its segmentation, event-based flows and ecommerce revenue attribution are excellent.

But I wouldn't pick it simply because you have lots of clients. Its strengths are really customer data + ecommerce automation, rather than being an agency operations platform.

Klaviyo

5. Transpond — interesting wildcard for white-label agencies

Transpond is particularly interesting if you want the client to experience your agency as the platform. It offers centralized campaigns, automations, reporting, CRM integrations and built-in white labeling. transpond.io

Transpond

One important distinction

If by "performance dashboards" you mean:

"I want one dashboard where I can see Client A's email revenue, Client B's open/click performance, Client C's leads, etc., and automatically send branded monthly reports"

I'd actually consider two layers:

Email platform → Campaign Monitor / ActiveCampaign / Klaviyo
Agency reporting layer → AgencyAnalytics

AgencyAnalytics can pull data from many marketing sources and produce white-labeled dashboards, reports, custom domains and automated client reporting. agencyanalytics.com

AgencyAnalytics

That setup is often better than trying to force the email platform itself to become your entire client reporting system.

My recommendation by agency type

• Mostly newsletters + basic automations: Campaign Monitor
• Advanced email automation + CRM: ActiveCampaign
• Ecommerce/Shopify clients: Klaviyo
• Email + SMS + CRM + funnels + lead generation: HighLevel
• White-label/reseller business: Transpond
• Best reporting across multiple marketing channels: Email platform + AgencyAnalytics

If you tell me roughly how many clients you have (e.g. 5, 20, 50+), whether they're mostly ecommerce or B2B/local businesses, and whether you need true white-labeling, I can narrow this down to the 2–3 best choices and compare their actual agency pricing.

If your goal is one operating system for an agency managing newsletters + automations + client reporting, I’d narrow it to these:

My recommendation: ActiveCampaign + Databox

If email is the core service you're selling, I'd use ActiveCampaign as the execution layer and Databox as the agency-wide reporting layer.

ActiveCampaign

• Excellent newsletter/campaign management
• Sophisticated behavioral automations
• Segmentation, tagging, lead scoring, journeys, etc.
• Good fit when different clients have substantially different email strategies
• Stronger email/automation capabilities than trying to make a reporting platform do everything

Databox

• Centralizes performance data across clients
• Lets you create separate dashboards for each client while maintaining agency-level views
• Supports reusable dashboard/report templates
• 130+ integrations and automated branded reports
• Particularly useful if you want your team to see all clients' performance from one place, rather than logging into each client's email account. databox.com

So the architecture becomes:

Client A → ActiveCampaign → Databox → Client dashboard
Client B → ActiveCampaign → Databox → Client dashboard
Client C → ActiveCampaign → Databox → Client dashboard

That separation is actually a strength: your email team gets a powerful email platform, while your account-management team gets a consistent reporting interface.

If you want fewer tools: HubSpot

I'd seriously consider HubSpot if your clients need more than newsletters—CRM, lead management, sales pipelines, forms, landing pages, lead nurturing, etc.

It's probably the closest to an agency-wide all-in-one. The tradeoff is that it can become expensive and/or overkill if what you're really selling is email marketing.

If you mostly serve ecommerce: Klaviyo

For Shopify/ecommerce clients, I'd put Klaviyo at the top. Its email/SMS automation and customer segmentation are exceptionally strong.

But I wouldn't choose it simply because you're an agency. If you have 15 clients across SaaS, professional services, healthcare, local businesses, ecommerce, etc., you'll probably appreciate the flexibility of ActiveCampaign/HubSpot more.

For the dashboard specifically: AgencyAnalytics vs Databox

This is where I'd make an important distinction.

AgencyAnalytics is better if the dashboard is primarily a client deliverable. It's purpose-built for agencies, with white-label dashboards, custom domains, automated reports, client permissions, templates, and 85+ integrations. agencyanalytics.com

Databox is better if you want the dashboard to be an internal operating system as well as a client dashboard—e.g., "show me which of our 30 clients have declining email revenue this week." Databox specifically supports cross-client performance views and reusable templates. databox.com

What I'd choose by agency type

Email-focused agency
→ ActiveCampaign + Databox

Ecommerce email agency
→ Klaviyo + Databox

Full-service digital agency
→ HubSpot + Databox/AgencyAnalytics

Performance marketing agency where reporting is the priority
→ AgencyAnalytics or Databox

Agency that wants one platform and doesn't mind paying more
→ HubSpot

One caveat: I wouldn't try to force the email platform itself to be your agency-wide dashboard. The better architecture is generally execution platform → centralized reporting layer. It keeps client accounts isolated while giving your agency a common KPI/reporting system.

If you tell me roughly how many clients you manage (e.g. 10/50/100), whether they're mostly ecommerce or B2B, and your monthly software budget, I can narrow this to the 2–3 best setups and estimate the actual monthly cost.

If you mean one platform where an agency can manage multiple clients’ newsletters + automations + reporting, I’d shortlist these:

My top pick: Campaign Monitor

campaignmonitor.com is probably the closest match to what you're describing.

It specifically supports agencies managing separate client accounts, with campaigns, automations, templates, analytics and reporting managed centrally. It also has permissions and private-label/white-label capabilities. Campaign Monitor

The big advantage is that you don't have to build an elaborate stack just to handle 10–30 clients. You can keep each client's subscribers and sending settings isolated while your agency manages them from the same ecosystem.

The interesting alternative: Transpond

transpond.io is worth a serious look if white-label client management is particularly important.

It explicitly positions itself around the "10 clients across 10 tools" problem and combines campaigns, automations, reporting, CRM synchronization and white-labeling. Transpond

I'd investigate this one if you want clients to feel like they're using your agency's platform, rather than Campaign Monitor with your agency sitting on top of it.

If reporting is the bigger problem

I'd separate email execution from client performance reporting.

For example:

Campaign Monitor/ActiveCampaign → AgencyAnalytics

agencyanalytics.com is purpose-built for agencies and supports white-label dashboards, automated reports, custom branding and 85+ integrations. AgencyAnalytics AgencyAnalytics

That gives you a much stronger setup if clients want a dashboard combining:

• Email opens/clicks
• Leads/conversions
• Google Ads
• Meta Ads
• GA4
• SEO
• Social
• CRM/revenue

You can then keep the email platform optimized for sending/automation and AgencyAnalytics optimized for the client-facing performance layer.

What I'd choose by agency type

• Mostly newsletters + basic automations: Campaign Monitor
• Email + automation + agency white-labeling: Transpond
• Complex lead nurturing/CRM automations: ActiveCampaign
• Full-service marketing + CRM + sales: HubSpot
• Mostly Shopify/ecommerce clients: Klaviyo
• You already have an email platform and need excellent client dashboards: AgencyAnalytics
• You want a true all-in-one agency/reseller platform: I'd investigate Transpond and the newer white-label platforms before committing to a conventional ESP.

One important distinction: "centralize" can mean two very different things. If you want your team to manage 20–50 client accounts from one place, Campaign Monitor/Transpond are especially relevant. If you want one executive dashboard showing every client's email + advertising + website performance, I'd lean toward Campaign Monitor/ActiveCampaign + AgencyAnalytics rather than forcing one product to do everything.

If you tell me roughly how many clients you manage (e.g. 10, 50, 100+) and whether they're mainly B2B, local businesses, or ecommerce, I can narrow this to the best 2–3 and compare their 2026 pricing, white-label capabilities, account structure, and reporting.

transpond.io is worth a serious look if white-label client management is particularly important.

It explicitly positions itself around the "10 clients across 10 tools" problem and combines campaigns, automations, reporting, CRM synchronization and white-labeling. transpond.io

I'd investigate this one if you want clients to feel like they're using your agency's platform, rather than Campaign Monitor with your agency sitting on top of it.

If reporting is the bigger problem

I'd separate email execution from client performance reporting.

For example:

Campaign Monitor/ActiveCampaign → AgencyAnalytics

If your goal is one agency operation that can manage newsletters + automations + client-level performance reporting, I’d shortlist these:

My recommendation

1. HighLevel — if you want to consolidate the whole agency stack

HighLevel is probably the closest match if "centralize" is the key requirement. It is designed around agencies managing separate client accounts, with CRM, email, automation, SMS, funnels, reporting and white-label capabilities in the same ecosystem. A recent 2026 agency comparison also ranks it as the strongest overall option for agencies wanting multi-client management and white-labeling. Tool Decision Engine

The tradeoff: its email/newsletter experience isn't as polished as dedicated email platforms, particularly for sophisticated ecommerce programs.

2. Campaign Monitor — if email is the core service

This is the one I'd investigate first if your agency primarily sells newsletter production + lifecycle email + reporting rather than CRM/funnel services. Its agency-oriented setup supports centralized client management, isolated accounts, template controls and client reporting. Campaign Monitor Hack'celeration

It's particularly attractive when you have, say, 10–30 clients all getting recurring newsletters and don't want your team jumping between completely unrelated accounts.

3. ActiveCampaign — if automation is where you make money

If you're building sophisticated:

• welcome sequences
• lead nurturing
• abandoned-cart/re-engagement flows
• behavioral segmentation
• CRM-triggered emails
• lead scoring

…I'd favor ActiveCampaign. Its automation capabilities are considerably deeper than Campaign Monitor, and agency-focused comparisons consistently put it near the top for automation-heavy work. US Tech Automations Campaign Monitor

The weakness is that the agency/multi-client experience isn't as elegant, so you may still want a separate reporting layer.

One important distinction

I'd actually separate "email platform" from "agency reporting platform."

For example:

Campaign Monitor / ActiveCampaign / Klaviyo
→ campaigns, lists, segmentation, automations, sends

AgencyAnalytics / similar reporting layer
→ one dashboard per client, cross-channel KPIs, branded reports, scheduled reporting

That architecture can be better than trying to force one tool to do everything. Agency reporting platforms are specifically designed around consolidating data across multiple clients and marketing channels. ClicData

What I'd choose by agency type

• General marketing agency: HighLevel
• Email/newsletter agency: Campaign Monitor
• Email automation/lead-gen agency: ActiveCampaign + reporting layer
• Ecommerce retention agency: Klaviyo
• Small/budget agency: Brevo
• Enterprise/B2B clients: HubSpot

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether they're mostly B2B, ecommerce, or local/service businesses, I can narrow this to the 2–3 best options and compare actual agency pricing, client limits, white-labeling, dashboards, and automation capabilities.

For example:

Campaign Monitor / ActiveCampaign / Klaviyo
→ campaigns, lists, segmentation, automations, sends

AgencyAnalytics / similar reporting layer
→ one dashboard per client, cross-channel KPIs, branded reports, scheduled reporting

3. ActiveCampaign — if automation is where you make money

If you're building sophisticated:

• welcome sequences
• lead nurturing
• abandoned-cart/re-engagement flows
• behavioral segmentation
• CRM-triggered emails
• lead scoring

If your agency needs to run newsletters + automations for multiple clients and give each client a polished performance dashboard, I’d shortlist these:

My top recommendation: Klaviyo + AgencyAnalytics

For an agency managing, say, 10–50 clients, I wouldn't try to force one platform to do everything.

Use Klaviyo for the actual email marketing:

• Campaign/newsletter creation
• Segmentation
• Automated flows
• A/B testing
• Email/SMS analytics
• Ecommerce integrations
• Multiple client accounts

Klaviyo now has Portfolios, which give agencies a higher-level view across multiple accounts and allow performance comparison across accounts. academy.klaviyo.com

Then use AgencyAnalytics for the agency/client reporting layer.

AgencyAnalytics is particularly compelling because it is designed around the agency model: separate clients, white-label dashboards, automated reports, client access, templates, and 85+ integrations. It can pull email data from platforms including Klaviyo, ActiveCampaign, Mailchimp, Brevo, Campaign Monitor, ConvertKit and Drip. agencyanalytics.com

It also supports roll-up dashboards, so internally you can see performance across multiple clients while clients see only their own data. help.agencyanalytics.com

When I'd choose the others

Klaviyo alone — best if you're primarily an email/ecommerce agency. Its multi-account/portfolio functionality is getting quite good, and you can manage multiple accounts from a unified view. academy.klaviyo.comhelp.klaviyo.com

HubSpot — better if your service includes CRM, lead nurturing, sales pipelines, landing pages, forms, and broader inbound marketing, rather than primarily newsletters/lifecycle email.

ActiveCampaign — excellent if clients are mostly SMBs and the emphasis is email automation and lead nurturing rather than sophisticated ecommerce marketing.

AgencyAnalytics + whichever ESP each client uses — my choice if clients come to you already using different systems. AgencyAnalytics can normalize the reporting layer while you keep each client's preferred email platform. agencyanalytics.com

What I'd build for an agency

A clean setup would be:

Agency
→ AgencyAnalytics
→ Client A → Klaviyo
→ Client B → Klaviyo
→ Client C → ActiveCampaign
→ Client D → Mailchimp
→ Client E → HubSpot

AgencyAnalytics becomes the single client-facing reporting portal, while the underlying platforms remain responsible for actually sending email and running automations.

That separation is important: email platforms are generally better at executing campaigns; agency reporting platforms are better at presenting results across clients.

If you tell me roughly how many clients you manage, whether they're mostly ecommerce or lead-gen, and your monthly budget, I can narrow this down to the best 2–3 setups with actual pricing and the pros/cons of each.

If you’re an agency managing multiple client brands, I’d separate the problem into two layers: email execution/automation and agency-level reporting. There isn’t one platform I’d pick blindly for both.

My shortlist

🥇 My pick: ActiveCampaign + AgencyAnalytics

For what you described, this is probably the strongest setup.

ActiveCampaign handles the actual client marketing: newsletters, segmentation, journeys, triggers, lead nurturing, etc. Its agency offering specifically talks about managing multiple clients and standardizing campaigns/workflows, and its reporting covers campaign and automation performance. www.activecampaign.com

Then put AgencyAnalytics on top as the agency reporting layer. It supports 85+ integrations, including ActiveCampaign, and gives you customizable/white-label dashboards, automated reports, client access, and cross-client reporting. agencyanalytics.com

AgencyAnalytics
ActiveCampaign

The nice architecture is:

Client A → ActiveCampaign → AgencyAnalytics → Client A dashboard
Client B → ActiveCampaign → AgencyAnalytics → Client B dashboard
Client C → ActiveCampaign → AgencyAnalytics → Client C dashboard

And internally, you can create roll-up dashboards to see performance across clients. AgencyAnalytics currently supports roll-up reports across up to 50 clients. help.agencyanalytics.com

🥈 Brevo if keeping costs down matters

Brevo is particularly interesting if you have a lot of smaller clients. Its Enterprise offering has sub-accounts/sub-organizations, allowing an agency to manage multiple client entities from an admin account while keeping their contacts, dashboards, API keys and permissions separated. help.brevo.com

It also connects to AgencyAnalytics, so you can use Brevo for execution and AgencyAnalytics for polished client reporting. help.agencyanalytics.com

Brevo

🥉 HighLevel if you want a true agency operating system

I'd look at HighLevel if your agency wants more than email—CRM, lead capture, pipelines, SMS, funnels, automations, appointments, etc.

It's more of an agency platform than a pure email platform. If your primary service is email newsletters + lifecycle automation, I prefer ActiveCampaign. If you're running lead generation + CRM + marketing automation for clients, HighLevel becomes much more compelling.

AgencyAnalytics also has a HighLevel integration. agencyanalytics.com

One important distinction

If by "performance dashboards" you mean:

"Show each client opens, clicks, conversions, revenue, unsubscribe rate, campaign performance, automation performance, and maybe Google/Meta/website results in a beautiful client portal."

Then don't make the email platform responsible for the dashboard. Use a dedicated agency reporting layer.

AgencyAnalytics can combine email data with things like Google Analytics, Google Ads, social, SEO, CRM and other sources into the same client dashboard. help.agencyanalytics.com

My ranking for your exact use case:

1. ActiveCampaign + AgencyAnalytics — best overall
2. Brevo + AgencyAnalytics — best value / lots of smaller clients
3. HighLevel — best if CRM/lead-gen is part of the service
4. Campaign Monitor + AgencyAnalytics — best if newsletters are the overwhelming focus
5. ActiveCampaign alone — simplest, but weaker as an agency-wide reporting layer

If you tell me roughly how many clients you have (e.g. 10, 50, 200), average contacts per client, and whether you need white-label/client login, I can narrow this down to the best 2–3 setups and estimate the monthly software cost.

For an agency managing multiple clients, the “best” platform depends on whether you care most about centralized client management, deep automations, or beautiful reporting dashboards. A lot of popular email tools are built for a single brand, not an agency portfolio. www.sasanova.com

Here are the strongest options:

My shortlist by agency type

1. Newsletter + content marketing agency (10–50 clients)
→ Campaign Monitor + AgencyAnalytics/Looker Studio

• Easy client separation
• Simple approvals
• Strong reporting story
• Good for monthly retainers

www.campaignmonitor.com

2. Lead generation / funnel agency
→ HubSpot or HighLevel

• Track leads from ads → email → sales pipeline
• Show clients revenue attribution
• Better for “we generate business” positioning

3. Marketing automation consultancy
→ ActiveCampaign

• Build sophisticated sequences:
  • onboarding flows
  • abandoned cart
  • lead scoring
  • reactivation campaigns

hackceleration.com

4. Small boutique agency trying to maximize margin
→ HighLevel or Zoho Campaigns

• Lower operational overhead
• Easier to package as a monthly service

www.zoho.com

A practical agency stack I’d consider

Client-facing layer

• HighLevel or HubSpot (CRM + automations)
• Looker Studio / AgencyAnalytics (performance dashboards)

Email execution

• Campaign Monitor for newsletters
• ActiveCampaign for complex journeys

Reporting metrics

• Subscribers added
• Deliverability
• Open/click trends (with the caveat that privacy changes have made opens less reliable)
• Conversion events
• Revenue/leads generated
• Automation performance

If I had to pick one default:

• Most agencies: HighLevel
• Premium B2B/full-service agencies: HubSpot
• Email-first agencies: Campaign Monitor
• Automation specialists: ActiveCampaign

The biggest deciding factor is your business model: Are you managing email as a service for clients, or are you building the automation systems that drive their sales?

If you mean one agency operating email for many different clients—newsletters + automated journeys + client-facing performance reporting—I’d shortlist these:

🥇 My pick: Campaign Monitor

For an agency whose core service is email newsletters and lifecycle email, I'd start with Campaign Monitor. It has an agency-oriented client-management model, centralized management, white-label reporting, and tools for sharing/locking templates across client accounts. Recent agency-focused comparisons also put it at the top specifically for multi-client agencies. hackceleration.com

The big advantage is that it feels like an agency email operating system, rather than a single company's marketing platform that you're trying to bend around multiple clients.

🧠 If automations are the main thing: ActiveCampaign

If you're building things like:

• lead nurture sequences
• onboarding flows
• abandoned-cart/re-engagement
• behavioral branching
• lead scoring
• CRM-triggered emails
• sophisticated segmentation

I'd choose ActiveCampaign instead. Its automation capabilities are substantially deeper, and its agency program supports managing multiple client organizations. The tradeoff is that the agency/reporting experience isn't as cleanly centralized as Campaign Monitor. www.sasanova.comopenrateclub.com

🏢 If you want email + CRM + SMS + funnels: HighLevel

If your agency isn't just an email agency, HighLevel is worth serious consideration. Its sub-account architecture was designed around agencies, so you can maintain separate client environments while operating them from an agency-level system. It also brings CRM, SMS, funnels, forms and automation into the same ecosystem. tooldecisionengine.com

I'd pick this if your eventual goal is something like:

Client → CRM → lead capture → email → SMS → sales pipeline → reporting

rather than simply:

Client → newsletter → automation → email report

📊 One important distinction: dashboards

If by "performance dashboards" you mean a beautiful client portal showing email performance across all their campaigns, I'd actually consider separating the sending/automation platform from the reporting layer.

For example:

Campaign Monitor / ActiveCampaign / Klaviyo
→ sends emails + runs automations

AgencyAnalytics
→ creates the polished, client-facing reporting/dashboard layer

AgencyAnalytics specifically supports email dashboards pulling data from platforms including Klaviyo, HubSpot, ActiveCampaign and Mailchimp, with customizable KPIs and white-label reporting. agencyanalytics.com

That architecture can be considerably better once you have 10–30+ clients.

What I'd choose by agency type

General marketing agency, 5–30 clients:
→ Campaign Monitor + AgencyAnalytics

Automation/lifecycle-focused agency:
→ ActiveCampaign + AgencyAnalytics

Full-service lead-gen agency:
→ HighLevel

Mostly Shopify/ecommerce clients:
→ Klaviyo + AgencyAnalytics

Lots of small clients where margin matters:
→ Brevo

Clients already using Mailchimp:
→ Stay with Mailchimp & Co rather than forcing migrations; its agency program provides centralized client management, although reporting/automation are less compelling. hackceleration.comwww.sasanova.comtooldecisionengine.comopenrateclub.com

One thing I'd not optimize for is simply "which has the cheapest email sends." For an agency, the expensive part is usually switching between accounts, rebuilding templates, managing permissions, producing reports, and onboarding clients. Agency-focused comparisons consistently identify client isolation, centralized management, white-label reporting, and scalable billing as the important criteria. www.sasanova.comopenrateclub.com

If you tell me roughly how many clients you manage (e.g. 5, 20, 50), whether they're mostly ecommerce or service businesses, and whether clients need their own login, I can narrow this to the best 2–3 platforms and compare their actual 2026 pricing/workflows.

If you’re an agency managing multiple client brands, I’d separate the problem into two layers: email execution/automation and client-facing performance reporting. The best choice depends on whether you want one platform to do both.

My shortlist

🥇 My recommendation: ActiveCampaign + AgencyAnalytics

For an agency specifically doing newsletters + automated journeys + reporting across several clients, this is probably the sweet spot.

ActiveCampaign handles the actual marketing:

• newsletters/campaigns
• automated nurture sequences
• segmentation
• tagging
• lead scoring
• CRM
• client-specific automations

ActiveCampaign explicitly positions its platform for agencies managing multiple campaigns, contact lists and brand identities, and offers agency/partner tooling for scaling across clients. www.activecampaign.com

Then use AgencyAnalytics as the agency-wide reporting layer. It connects to ActiveCampaign plus other channels such as Google Analytics, Google Ads, social, SEO and ecommerce, allowing you to create a dashboard for each client. It supports white-label dashboards, client/staff permissions, automated reports and 85+ integrations. agencyanalytics.comagencyanalytics.com

The ActiveCampaign → AgencyAnalytics integration specifically pulls email-marketing metrics into customizable client dashboards and reports. www.activecampaign.com

That gives you something like:

Agency
→ Client A
→ ActiveCampaign account/workflows
→ AgencyAnalytics dashboard

→ Client B
→ ActiveCampaign account/workflows
→ AgencyAnalytics dashboard

→ Client C
→ ActiveCampaign account/workflows
→ AgencyAnalytics dashboard

…and you can keep your internal agency view across clients while giving each client a restricted branded dashboard.

🥈 If you want one ecosystem: HubSpot

I'd choose HubSpot if your agency also manages CRM, sales pipelines, lead generation, forms, websites and attribution, rather than primarily email.

HubSpot's multi-account management can report across separate accounts, create unified dashboards, compare accounts, and copy marketing assets such as emails, forms and lists between accounts. www.hubspot.com

It's much more powerful as an agency operating system, but it can be considerably more platform than you need if your core service is newsletters and lifecycle email.

🥉 If cost matters: Brevo

Brevo is worth looking at if you're managing a lot of smaller clients. Its Enterprise setup supports separate client sub-accounts/sub-organizations while letting an agency administer them from a central account, with separate contacts, dashboards, API keys and permissions. help.brevo.com

I'd favor it for high-volume, relatively straightforward client email programs rather than sophisticated automation consulting.

What I'd pick by agency type

• Email marketing agency: ActiveCampaign + AgencyAnalytics
• Full-service digital agency: HubSpot
• Newsletter/content agency: Campaign Monitor
• Lots of small-business clients: Brevo
• Already have your email platforms and just need one reporting cockpit: AgencyAnalytics

One particularly attractive feature of AgencyAnalytics for your use case is roll-up reporting—it can combine data from multiple clients/brands/locations into one view while still maintaining individual client dashboards. agencyanalytics.comagencyanalytics.com

If you tell me roughly how many clients you manage (e.g. 5, 20, 100) and whether clients need their own login/white-labeled dashboard, I can narrow this to the best 2–3 setups and compare actual 2026 pricing.

If you're an agency managing multiple clients' newsletters + automations + reporting, I’d narrow the field to these:

🥇 My pick: Campaign Monitor

For your specific description—centralize newsletters, automations and performance dashboards for several clients—I'd start with Campaign Monitor.

It is unusually agency-oriented: Campaign Monitor specifically provides a centralized place to manage client accounts, campaigns, automations, templates and reporting. It also supports agency-oriented white labeling and client account management. www.campaignmonitor.com

Campaign Monitor for Agencies

Why I'd choose it:

• Separate client accounts without building a Frankenstein stack.
• Strong newsletter/campaign workflow.
• Automation journeys are good enough for most SMB clients.
• Templates can be standardized and locked.
• Reporting is designed with agency/client presentations in mind.
• Better fit than ecommerce-first platforms if your clients span different industries.

🥈 If automations are the main product: ActiveCampaign

If you're selling email strategy + sophisticated lifecycle automation, I'd choose ActiveCampaign instead.

It's considerably stronger for complex customer journeys, segmentation, lead scoring and CRM-style automation. It also integrates with AgencyAnalytics, allowing ActiveCampaign email metrics to feed into automated, client-facing dashboards. www.activecampaign.com

ActiveCampaign

The downside is that the agency/client reporting experience isn't as elegant out of the box as you'd ideally want. I'd pair it with AgencyAnalytics.

🥇 For a true agency operating system: HighLevel

If by "centralize" you mean:

I want one login where my agency can manage 20–50 client accounts, with each client having their own marketing environment.

Then HighLevel deserves serious consideration.

It's much broader than email—CRM, funnels, automation, SMS, reputation management, reporting, etc.—so it's particularly attractive if email is only one component of what you're selling.

HighLevel

The tradeoff: it's a much bigger/more complicated platform than you need if your agency is specifically an email/newsletter shop.

The reporting piece I'd seriously consider separately

If client-facing dashboards are important, AgencyAnalytics is worth looking at regardless of which email platform you choose.

It supports 85+ data sources, white-labeled dashboards, automated reports, custom domains, client logins and granular permissions. agencyanalytics.com

AgencyAnalytics

That gives you a stack like:

Campaign Monitor / ActiveCampaign → AgencyAnalytics → client dashboard

or

Klaviyo → AgencyAnalytics → client dashboard

This is often better than forcing the email platform itself to become your entire reporting system.

What I'd choose based on your agency

• 5–30 general SMB clients: Campaign Monitor
• Clients need sophisticated nurture/lead automation: ActiveCampaign + AgencyAnalytics
• You're a full-service marketing agency: HighLevel
• Mostly Shopify/ecommerce: Klaviyo + AgencyAnalytics
• Lots of small clients and cost is critical: Brevo
• Mostly basic newsletters: Campaign Monitor or Mailchimp

One important distinction: don't confuse an email platform's campaign reporting with a real agency dashboard. If clients expect a branded portal showing email + GA4 + paid ads + SEO + social performance, I'd deliberately use an ESP + dedicated reporting layer rather than trying to make the ESP do everything. AgencyAnalytics is specifically designed for that agency use case. mailchimp.com

If you tell me roughly how many clients you manage (e.g. 10, 30, 100), whether they're mostly ecommerce or B2B/local businesses, and whether you need white-labeling, I can narrow this to the best 2–3 setups and estimate the monthly cost per client.

If you’re managing email newsletters + automations + performance reporting for multiple clients, I’d narrow it to three serious options:

🥇 My pick: HighLevel

If the goal is genuinely “centralize everything for several clients,” I'd start with HighLevel.

It was built around agency sub-accounts, so you can keep each client's contacts, campaigns, automations, CRM data and reporting separated while managing them from an agency account. It also supports white-labeling, and its reporting can automatically send performance reports to client sub-accounts. www.gohighlevel.com

A particularly useful recent addition is email-specific dashboard widgets, which let you see delivery, engagement, campaign, workflow and template performance directly in HighLevel dashboards. help.gohighlevel.com

Choose HighLevel if:

• You manage ~5–100+ clients.
• You want each client to have their own workspace.
• You want email + CRM + SMS + forms + funnels + automation together.
• You want to white-label the client experience.
• You're selling the marketing system/service, not just newsletter production.

The downside: it's broader and more complicated than a dedicated email platform.

🥈 Campaign Monitor — best if you're an email/newsletter agency

If your agency primarily sells email marketing, I'd seriously consider Campaign Monitor for Agencies instead.

It has a particularly good agency model: centralized client management, separate client accounts, permissions, white-labeling, template locking, client billing, automations and an agency overview dashboard. www.campaignmonitor.com

This is probably the cleanest experience for an agency where email is the product.

For example:

Agency
→ Client A
→ Client B
→ Client C
→ Client D

All newsletters, journeys, templates and email metrics managed centrally.

I'd pick this over HighLevel if you don't need CRM/SMS/funnels and want your team to live primarily inside an excellent email platform.

🥉 ActiveCampaign — best for complex automations

ActiveCampaign is the one I'd choose when the actual differentiator is sophisticated lifecycle automation.

Think:

Lead → nurture → engagement scoring → sales handoff → purchase → onboarding → upsell → reactivation

rather than simply:

Newsletter → open/click → report

Its automation and CRM capabilities are excellent, but its multi-client agency architecture isn't as elegant as Campaign Monitor or HighLevel. Independent 2026 agency testing similarly puts ActiveCampaign ahead when automation depth is the priority. help.gohighlevel.comhackceleration.com

One important distinction: "performance dashboards"

If by dashboards you mean email performance only, HighLevel or Campaign Monitor can probably handle it.

If you mean:

Email + Google Ads + Meta Ads + GA4 + SEO + CRM + ecommerce + email

then I'd actually use a two-layer stack:

HighLevel or Campaign Monitor
→ newsletters + automations

AgencyAnalytics
→ client-facing performance dashboard

AgencyAnalytics currently connects to 85+ data sources, including HighLevel, Campaign Monitor, ActiveCampaign, HubSpot, Klaviyo, Mailchimp and others, and supports white-labeled dashboards and automated reporting. agencyanalytics.com

That gives you a much better client reporting layer than trying to make the email platform itself become your entire marketing BI system.

What I'd choose by agency type

Email/newsletter agency:
Campaign Monitor + AgencyAnalytics

Full-service digital marketing agency:
HighLevel + AgencyAnalytics

Marketing automation/CRM agency:
ActiveCampaign + AgencyAnalytics

Want the fewest tools possible:
HighLevel

Want the cleanest email-specific agency workflow:
Campaign Monitor

If you tell me roughly how many clients you have, average contacts per client, and whether you need white-label/client logins, I can narrow this down to the best 1–2 setups and compare the likely monthly cost.

If you're an agency managing multiple client brands, I’d narrow it to these options:

🥇 My pick: HighLevel

If your goal is genuinely to centralize newsletters + automations + client performance dashboards, HighLevel is probably the closest fit.

It uses agency/sub-account architecture, so each client can have its own environment while your agency manages everything centrally. It now also has dedicated email widgets in sub-account dashboards and custom reports, including campaign/workflow/template performance. tooldecisionengine.com

It also goes beyond email: CRM, forms, landing pages, SMS, pipelines and automations are all in the same ecosystem. tooldecisionengine.com

I'd choose it if: your agency wants to standardize a marketing stack and potentially sell the platform/automation infrastructure as part of your service.

🥈 Campaign Monitor — if email is the core service

Campaign Monitor is particularly interesting for an agency whose main deliverable is email newsletters and lifecycle campaigns, rather than an entire CRM/marketing platform.

Recent agency-focused testing specifically highlighted its multi-client account management, isolated client accounts, brand-locked templates and agency-oriented reporting. hackceleration.com

So your workflow can look more like:

Agency account → Client A → Client B → Client C → Client D

rather than having your team constantly log in/out of individual client accounts.

I'd choose it if: you don't need CRM/SMS/landing pages and want a clean, email-first agency operation.

🥉 ActiveCampaign — if automation is the differentiator

If you're selling things like:

• Lead nurture
• Welcome sequences
• Re-engagement
• Lead scoring
• Behavioral triggers
• Sales follow-up
• CRM-driven email
• Complex branching journeys

I'd seriously consider ActiveCampaign.

Its big advantage is automation depth rather than agency dashboarding. Current agency comparisons also put it ahead when the agency's primary service is sophisticated automation. hackceleration.com

The downside is that I'd probably pair it with a dedicated reporting platform rather than expect it to be your entire client-reporting system.

📊 The reporting solution I'd seriously consider: AgencyAnalytics

There's an important distinction here:

Your email platform doesn't necessarily need to be your client reporting platform.

AgencyAnalytics can pull data from ActiveCampaign, Brevo, Campaign Monitor, HighLevel, HubSpot, Klaviyo, Mailchimp and other email platforms, alongside GA4, PPC, SEO, social, ecommerce, etc. agencyanalytics.com

It gives you:

• Separate client dashboards
• Agency branding / white-label dashboards
• Automated reports
• Client logins
• Cross-channel reporting
• Custom metrics/goals
• Email + website + ads + SEO in one report

agencyanalytics.com

This is particularly compelling if your clients don't just ask "How did our emails perform?" but instead ask "Is our marketing working?"

What I'd build for an agency

Option A — simplest

HighLevel

Newsletter → Automation → CRM → Reporting → Client dashboard

This minimizes the number of systems your team has to maintain.

Option B — best email-specialist stack

Campaign Monitor + AgencyAnalytics

Campaign Monitor → newsletters/automations
↓
AgencyAnalytics → client dashboards + automated reports

This is probably my favorite setup if you're an email marketing agency rather than a general digital agency.

Option C — sophisticated B2B

ActiveCampaign + AgencyAnalytics

ActiveCampaign → CRM + behavioral automation + email
↓
AgencyAnalytics → client-facing reporting

I'd choose this for clients where automation and lead nurturing are more important than simply sending newsletters.

Option D — ecommerce

Klaviyo + AgencyAnalytics

Especially if your clients use Shopify and care about revenue attribution, abandoned carts, post-purchase flows, segmentation and lifecycle marketing.

One important consideration

I wouldn't optimize purely for "one dashboard." For an agency, the more important architecture is:

Central agency management → isolated client workspaces → reusable templates/automations → client approval → automated reporting → white-label dashboard

That separation becomes extremely valuable once you're managing 10–30+ clients. Agency-focused evaluations specifically call out multi-client isolation, white-labeling, per-client reporting and scalable pricing as the features that distinguish agency software from ordinary email tools. hackceleration.com

If you tell me roughly how many clients you have (e.g. 5, 20, 50), whether they're mostly B2B or ecommerce, and whether you need clients to log in/approve campaigns, I can narrow this to the best 2–3 and compare actual 2026 pricing.

If you’re an agency managing multiple client email programs, I’d separate the problem into two layers:

1. Email execution: newsletters, segmentation, automations, deliverability.
2. Agency reporting: one place to see every client’s performance and give clients branded dashboards.

My shortlist

Recent agency-focused comparisons similarly put Campaign Monitor ahead for multi-client management, ActiveCampaign for automation-heavy work, and Brevo for lower-cost agency operations. hackceleration.com

What I'd actually build

For a typical agency, my favorite setup is:

ActiveCampaign + AgencyAnalytics

Use ActiveCampaign separately for each client's email program—newsletters, journeys, segmentation, lead nurturing, etc.—and use AgencyAnalytics as the agency-wide reporting layer.

AgencyAnalytics can pull email data from platforms including ActiveCampaign, HubSpot, Klaviyo, Mailchimp and Brevo, while giving you client-specific dashboards, automated reports, white labeling, custom domains, and data from 85+ marketing integrations. agencyanalytics.com

That means your internal view can look roughly like:

Agency

• Client A → email + GA4 + Google Ads + social
• Client B → email + GA4 + Meta Ads
• Client C → email + ecommerce + paid media
• Client D → email + CRM + website

while each client gets only their own branded dashboard.

When I'd choose something else

Choose HighLevel if your agency wants to sell a broader "marketing system" rather than just email. It's particularly attractive when CRM, SMS, funnels, lead management and automation should all live together. A recent 2026 comparison rates it highly for full-service agencies because of its multi-client setup and white-label capabilities. tooldecisionengine.com

Choose Campaign Monitor if your core business is "we manage newsletters and email campaigns for lots of brands." Its agency-oriented multi-client workflow makes it particularly compelling when you don't need a full CRM. hackceleration.com

Choose Klaviyo if a large portion of your clients are Shopify/ecommerce. Its segmentation, behavioral flows and revenue attribution are difficult to beat for ecommerce.

Choose HubSpot when your clients care about the entire funnel—CRM → lead → email → sales → revenue—and they're willing to pay for a much larger platform. It can be overkill for straightforward newsletter clients. tooldecisionengine.com

Choose Brevo if you're managing a lot of smaller clients and keeping software costs down matters. It combines email/SMS with relatively straightforward agency management, and AgencyAnalytics can bring its campaign data into client dashboards. agencyanalytics.com

My ranking for your exact use case

If the requirement is "one agency operation managing newsletters + automations + performance dashboards for many clients", I'd rank:

1. ActiveCampaign + AgencyAnalytics — best balance of powerful email automation and professional agency reporting
2. HighLevel — best if you want everything under one roof
3. Campaign Monitor + AgencyAnalytics — best if newsletters are the primary service
4. Klaviyo + AgencyAnalytics — best if you're heavily ecommerce-focused
5. Brevo + AgencyAnalytics — best for keeping per-client costs low
6. HubSpot — best for high-value clients needing CRM/revenue infrastructure

The key insight is that I wouldn't force the email platform to also be your reporting platform. A dedicated reporting layer gives you much more flexibility when Client A uses Klaviyo, Client B uses ActiveCampaign, and Client C uses HubSpot. AgencyAnalytics specifically supports that cross-platform model. agencyanalytics.comagencyanalytics.com

If you tell me roughly how many clients you manage (e.g. 5, 20, 50+) and whether they're mostly ecommerce, B2B, or local businesses, I can narrow this to the best 2–3 setups and estimate the monthly software cost per client.

If you’re an agency managing multiple clients, I’d separate the problem into two layers:

1. Email/automation platform — actually sends newsletters and runs automations.
2. Agency reporting layer — gives you one place to monitor all clients and deliver branded dashboards.

Trying to force one tool to do both is usually where things get awkward.

My shortlist

Independent 2026 comparisons similarly put HighLevel toward the top for agency-wide multi-client management, ActiveCampaign for automation-heavy work, Klaviyo for ecommerce, and Campaign Monitor for simpler multi-client newsletter operations. tooldecisionengine.comwww.activecampaign.comagencyanalytics.comagencyanalytics.comagencyanalytics.com

🥇 Best overall: HighLevel

HighLevel

If your goal is "I want my agency to log into one system and manage 10–50 clients", I'd look hardest at HighLevel.

You get client sub-accounts, email campaigns, workflows/automations, CRM, forms, funnels, SMS, etc. The agency-oriented architecture is much closer to what you're describing than a conventional ESP.

Choose it if: your agency wants to sell a broader "marketing automation" service rather than simply email marketing.

Downside: it can be overkill if all you do is newsletters + email sequences, and it's not my first choice for sophisticated ecommerce email.

🥈 Best email-first option: ActiveCampaign

ActiveCampaign

I'd pick ActiveCampaign if email automation is the core product you're selling.

It's particularly strong for:

• sophisticated customer journeys
• behavioral triggers
• lead nurturing
• segmentation
• CRM integration
• reusable automation templates
• multiple client accounts

It also integrates with AgencyAnalytics for automated client reporting. www.activecampaign.com

The weakness is that the agency management/reporting experience isn't as compelling as an actual agency platform.

🛒 Best for ecommerce clients: Klaviyo

Klaviyo

If most of your clients are Shopify/ecommerce brands, I'd probably choose Klaviyo over everything else.

It's excellent for:

• newsletters
• abandoned cart
• post-purchase flows
• segmentation
• product-based personalization
• revenue attribution
• sophisticated lifecycle automation

And you can put the performance data into an agency-wide reporting layer. AgencyAnalytics currently supports Klaviyo reporting and white-labeled dashboards. agencyanalytics.com

The catch: Klaviyo isn't really designed to be your agency's central operating system.

🏢 Best for B2B: HubSpot

HubSpot

If your clients are B2B companies where email is intertwined with sales pipelines, CRM, lead scoring and sales follow-up, HubSpot becomes much more attractive.

It's less appealing if your agency primarily does inexpensive newsletter management for local businesses because the platform can become expensive and unnecessarily complex.

⭐ The setup I'd actually recommend for an agency

Rather than trying to find one magical platform, I'd consider:

Email platform → AgencyAnalytics → client dashboard

For example:

Klaviyo / ActiveCampaign / Mailchimp
↓
AgencyAnalytics
↓
One dashboard per client + agency-wide visibility

AgencyAnalytics supports email data from ActiveCampaign, Brevo, Campaign Monitor, Constant Contact, Drip, HighLevel, HubSpot, Klaviyo, Mailchimp and others, and provides white-labeled dashboards, client access and scheduled reporting. agencyanalytics.com

That's particularly compelling if your clients also have Google Ads, Meta Ads, GA4, SEO, etc. You can put email performance alongside those channels rather than giving the client a separate email report. agencyanalytics.com

My recommendation by agency type

Generalist marketing agency:
→ HighLevel + AgencyAnalytics

Email marketing agency:
→ ActiveCampaign + AgencyAnalytics

Ecommerce/Shopify agency:
→ Klaviyo + AgencyAnalytics

B2B agency:
→ HubSpot

Small-business newsletter agency:
→ Campaign Monitor or Brevo + AgencyAnalytics

If you want one login/control center above everything else:
→ HighLevel

One important distinction: AgencyAnalytics doesn't replace your email platform. It's the reporting/visibility layer; it pulls email performance from the systems actually sending the campaigns. agencyanalytics.com

If you tell me roughly how many clients you have (e.g. 5, 20, 100), whether they're mostly ecommerce or B2B/local businesses, and whether you need white-labeling, I can narrow this to the best 2–3 setups and estimate the monthly cost per client.

If your main requirement is “one place for my agency to manage newsletters + automations + client-level performance reporting across many brands,” I’d narrow it to three serious options.

My ranking

\*ActiveCampaign becomes particularly compelling when paired with AgencyAnalytics.

1. Campaign Monitor — my pick if you're primarily an email agency

This is probably the closest match to exactly what you described.

Campaign Monitor has an agency-specific structure where you can manage separate client accounts from one interface, with client-specific lists, campaigns, automations, templates, permissions and reporting. It also supports agency branding/white-labeling and client-specific billing. www.campaignmonitor.comwww.campaignmonitor.com

The nice part is that you're not trying to force a generic marketing platform into an agency workflow.

I'd choose it if:

• You have 5–50+ email clients.
• Newsletters are a major deliverable.
• You want clients separated cleanly.
• Your team needs reusable templates.
• You want clients to have some access without exposing other accounts.
• You want your agency brand rather than the software vendor's brand.

Campaign Monitor also has an agency-level overview where you can quickly see campaign metrics across clients. www.campaignmonitor.comwww.campaignmonitor.com

Best fit: email/newsletter agency, creative agency, fractional marketing team.

2. HighLevel — best if email is only part of what you sell

HighLevel is the one I'd look at if you want to eventually centralize email + CRM + SMS + funnels + forms + calendars + lead management + automation.

Its architecture is particularly agency-friendly: each client can have a separate sub-account, while you manage them from the agency level. HighLevel also supports white-labeling, custom domains and branded client experiences. www.gohighlevel.com

The big advantage is that you can build an automation such as:

Newsletter → link click → lead tagged → CRM opportunity → sales follow-up → appointment → SMS reminder

without stitching together five different systems.

I'd choose HighLevel over Campaign Monitor if:

• You're a full-service digital/lead-gen agency.
• Email is tied closely to lead generation.
• You want to sell a branded marketing platform to clients.
• SMS, CRM and funnels matter.
• You want to consolidate your tech stack.

The downside: it's much more software than you need if you're basically an email/newsletter agency.

3. ActiveCampaign — best automation engine

ActiveCampaign is the choice I'd make if your differentiator is sophisticated lifecycle automation rather than agency account management.

It's particularly strong for things like:

• Lead nurturing
• Conditional journeys
• Behavioral triggers
• Lead scoring
• CRM-triggered email
• Segmentation
• Complex branching workflows

Current agency-focused comparisons consistently put ActiveCampaign near the top for automation depth, while noting that its multi-client management isn't as purpose-built as Campaign Monitor's. hackceleration.com

So I'd think of it as:

Campaign Monitor = better agency operating system for email

ActiveCampaign = better automation engine

The setup I'd actually recommend

If you're managing 10+ clients, I'd seriously consider separating email execution from client reporting:

Campaign Monitor / ActiveCampaign
↓
AgencyAnalytics
↓
One branded dashboard per client

AgencyAnalytics can pull email metrics from platforms including Mailchimp, ActiveCampaign and others, then combine them with Google Analytics, PPC, SEO, social, etc. It supports white-labeled dashboards, reports, custom domains and automated reporting. agencyanalytics.com

That gives you a much better client experience:

Client A

• Newsletter performance
• Automation performance
• Website traffic
• Leads/conversions
• Google Ads
• Social
• Monthly report

rather than asking the client to log into the email platform to figure out what happened.

What I'd pick by agency type

Pure email/newsletter agency:
→ Campaign Monitor + AgencyAnalytics

Full-service marketing agency:
→ HighLevel

Sophisticated B2B/lifecycle automation:
→ ActiveCampaign + AgencyAnalytics

E-commerce clients:
→ Klaviyo + AgencyAnalytics — especially if most clients are Shopify/e-commerce brands.

Small agency trying to keep costs down:
→ Brevo + AgencyAnalytics

One important distinction

If by "centralize" you mean literally one login where your team can jump between 20 client accounts, maintain separate client data, manage newsletters/automations, and see everyone's performance, I'd put Campaign Monitor at #1.

If you mean one platform that becomes the operating system for every client's marketing, I'd put HighLevel at #1.

If you tell me roughly how many clients you manage (e.g. 5, 20, 50), whether they're mostly B2B/local businesses/e-commerce, and whether clients need their own login/dashboard, I can narrow this down to the best 2–3 setups and estimated monthly cost.