Best Email Marketing Software for Agencies
Last updated August 22, 2026
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Agencies managing multiple client accounts need email marketing platforms that scale across users, contacts, and sub-accounts without forcing a separate subscription per client. This ranking compares five platforms strictly on the pricing tiers and features provided: multi-user/sub-account support, built-in CRM, automation depth, landing pages, SMS, and API access. Tools built around agency-specific structures (sub-accounts, multi-seat tiers) rank higher than single-account tools with limited team seats, and pricing at each relevant tier is called out directly so you can match cost to client volume.
Full ranking
Best for: Agencies running many client accounts under one login
GoHighLevel's Starter plan ($97/mo) already includes 3 Sub-Accounts with unlimited contacts and unlimited users, and the Agency Pro plan ($497/mo) adds unlimited Sub-Accounts plus SaaS Mode — a structure built specifically for running multiple client accounts under one subscription. It also bundles CRM & Pipelines, Workflow Automation, and API Access (Basic on Unlimited, Advanced on Agency Pro) as core features.
- Built-in CRM / contact scoring
- Public REST API
- Marketing automation workflows
Best for: Agency teams needing multi-user seats with built-in CRM
ActiveCampaign's Pro plan ($79/mo) supports 3 users and Enterprise ($145/mo) supports 5, giving agency teams shared multi-step marketing automation and CRM & ecommerce integrations included across all tiers. Landing pages are available from the Plus plan ($49/mo) upward, useful for building client campaign pages without a separate tool.
- Built-in CRM / contact scoring
- Marketing automation workflows
- Landing page builder
Best for: Larger agencies with budget for a full CRM-and-marketing suite
HubSpot's Professional plan ($890/mo pay-monthly) includes 3 Core Seats and 3,000 HubSpot Credits with omni-channel marketing automation and CRM lead scoring, while Enterprise ($3,600/mo) scales to 5 Core Seats — though both require one-time onboarding fees ($3,000 and $7,000 respectively) that agencies must budget for. Email health reporting (deliverability_tools) gains additional features at Professional/Enterprise.
- Built-in CRM / contact scoring
- Deliverability tools (warm-up, monitoring)
- AI content assistant
Best for: Agencies handling straightforward email/landing-page campaigns for clients
GetResponse's Marketer plan ($59/mo) unlocks unlimited automation workflows and ecommerce integrations like abandoned cart recovery, useful for running client campaigns, but SMS marketing and transactional email are only listed under the custom-priced Enterprise plan, limiting mid-tier agency use of those channels.
- Landing page builder
- Marketing automation workflows
- AI content assistant
Best for: Agencies testing a single small client's email program at no cost
Klaviyo's only documented plan is Free, capped at 250 profiles and 500 emails/month with $5 of mobile messages included — workable for a single small client test but no multi-user or sub-account structure is given in the data, making it the weakest fit for managing multiple agency clients at scale.
- Free forever plan
- SMS marketing
- AI content assistant
Buying guide
For agencies, the first filter should be how a platform structures multi-client access: GoHighLevel's Sub-Account model (3 on Starter at $97/mo, unlimited on Agency Pro at $497/mo) is built for this, while ActiveCampaign and HubSpot instead scale via multi-seat plans (ActiveCampaign Pro at 3 users/$79mo, Enterprise at 5 users/$145mo; HubSpot Professional with 3 Core Seats at $890/mo). Next, weigh total cost including hidden fees — HubSpot's Professional and Enterprise tiers carry one-time onboarding fees of $3,000 and $7,000 on top of monthly pricing. Check which channels are actually available at the tier you'd realistically buy: GetResponse holds SMS and transactional email back for its custom-priced Enterprise plan, while GoHighLevel bundles SMS marketing as a core feature at lower tiers. Finally, consider whether you need API access to build custom client workflows (GoHighLevel offers Basic and Advanced tiers) or whether a free tier is enough for a pilot client (HubSpot Free for 2 users, Klaviyo Free up to 250 profiles).
Frequently asked questions
Which platform is priced specifically for agencies managing multiple client accounts?
GoHighLevel is structured this way: Starter ($97/mo) includes 3 Sub-Accounts with unlimited contacts and users, and Agency Pro ($497/mo) adds unlimited Sub-Accounts plus SaaS Mode.
Are there hidden costs agencies should watch for?
Yes — HubSpot's Professional plan ($890/mo) and Enterprise plan ($3,600/mo) each require a separate one-time onboarding fee, $3,000 and $7,000 respectively, not included in the monthly price.
Which tools support multiple team seats for an agency staff?
ActiveCampaign's Pro plan includes 3 users and Enterprise includes 5 users; HubSpot's Professional plan includes 3 Core Seats and Enterprise includes 5 Core Seats.
Is there a free option agencies can use to trial a platform before committing?
HubSpot offers a Free tier for up to 2 users at $0/mo, and Klaviyo offers a Free forever plan capped at 250 profiles and 500 emails/month.
Which platform fits an agency that needs SMS marketing for clients?
GoHighLevel lists Email + SMS Marketing as a core feature across its plans, whereas GetResponse only includes SMS marketing on its custom-priced Enterprise plan, and Klaviyo's Free plan includes $5 of mobile messages per month.