Agency Email Stack  / Field Guide / May 2026

Two tools,
or one yellow giant?

A working comparison of the MailerLite + MailerSend combo against Mailchimp for an agency juggling clients who need marketing, transactional, or both. Scroll for the deep dive — then build your own client roster in the simulator and watch the two bills fight.

MailerLite — marketing MailerSend — transactional Mailchimp — all-in-one USD · platform cost only
01 / THE SHORT VERSION

The combo wins on the bill. Mailchimp wins on the single login.

Three facts decide most of this before you touch a feature list. They're the levers the simulator below pulls on.

Active

You pay for who you email

MailerLite bills only active subscribers — people emailed in the last 30 days. Mailchimp bills every contact in the audience, including unsubscribed and dormant ones.

$0

Transactional can stand alone

MailerSend sends transactional email by itself from free / $7. Mailchimp's transactional (Mandrill) is an add-on that requires a paid Standard plan underneath it — so you buy two things to send one.

×2

But it's two of everything

Two dashboards, two logins, two invoices, two support queues. The combo is cheaper, not simpler. That tax is real for a small team.

02 / WHAT EACH THING ACTUALLY IS

One sends the newsletters. One sends the receipts.

MailerLite and MailerSend are sibling products from the same company. They are not one platform — they're a marketing tool and a transactional tool that happen to share a parent, a design language, and a support team.

The marketing half

MailerLite

campaigns · lists · forms · automation

The Mailchimp-shaped half. Drag-and-drop builder, signup forms and pop-ups, landing pages, a website builder, segmentation, and automation workflows. Genuinely easy to use and consistently strong on deliverability. The automation is functional but shallower than Mailchimp or ActiveCampaign, and template design is more limited.

Free to 500 subs · Growing Business from $10/mo · Advanced from $20/mo · unlimited sends on paid plans
The transactional half

MailerSend

API · SMTP · receipts · alerts

The developer half. REST API and SMTP relay for password resets, order confirmations, alerts — the action-triggered mail. High deliverability, metered overage instead of hard cutoffs, multi-domain support that suits agencies. Note: it polices spam complaints hard and will auto-pause an account whose complaint rate spikes.

Free 500 emails · Hobby $7/5k · Starter $35/50k · Pro $110/50k · overage $0.80–1.20 per 1k
The incumbent

Mailchimp

marketing + transactional add-on + sites + SMS, one account

The all-in-one most clients already recognize. Deeper automation, a bigger template and integration ecosystem, and everything under a single login — which is its real advantage. The costs: contact-based pricing that counts unsubscribed and non-subscribed contacts, prices that have climbed 30%+ since 2022, auto-upgrades when you cross a tier with no grace period, and a transactional product (Mandrill) sold separately at $20 per 25,000-email block, available only on Standard and Premium. Extra seats, a custom domain, and a dedicated IP all cost more on top.

Free 500 contacts · Essentials from $13 · Standard from $20 · Premium from $350 · Transactional $20/25k block
03 / STRENGTHS & WEAKNESSES

Where each one earns its keep — and where it bites.

MailerLite + MailerSend

The two-tool stack

Strengths

  • Cheaper at almost every scale, and the gap widens as lists grow.
  • Active-subscriber billing — dead weight on a list doesn't cost you.
  • Transactional runs standalone from free/$7; no marketing plan hostage fee.
  • Clean marketing/transactional separation by design — good deliverability hygiene.
  • MailerSend multi-domain support fits managing several clients.

Weaknesses

  • Two dashboards, two bills, two logins — real operational drag.
  • Shallower automation & fewer templates than Mailchimp.
  • Free tiers trimmed (MailerLite cut to 500 subs in Sept 2025; MailerSend free is dev-only).
  • MailerSend auto-pauses on complaint spikes — risky with messy client lists.
  • Not a true multi-tenant agency console — isolation is manual.

Mailchimp

The all-in-one

Strengths

  • One login for everything — marketing, transactional, sites, SMS.
  • Deeper automation & branching journeys than MailerLite.
  • Bigger template & integration ecosystem.
  • Familiar to clients — less retraining, instant brand trust.
  • Mature CRM-ish features & reporting.

Weaknesses

  • Bills unsubscribed & inactive contacts — you pay for people you can't email.
  • Transactional requires a paid plan + Mandrill — two purchases for one job.
  • Silent auto-upgrades when a list crosses a tier.
  • Add-on creep — seats, custom domain ($9), dedicated IP ($29.95).
  • Steepest price curve of the three as audiences scale.
04 / PRICING REFERENCE

The list rates, before the simulator does the math.

Monthly, USD, publicly listed rates as of May 2026. Marketing tiers are billed by contacts; transactional by emails sent. Annual billing knocks ~10% (MailerLite/MailerSend) to 15% (Mailchimp, 10k+ contacts) off — not shown below.

Marketing by contacts / subscribers — monthly
ContactsMailerLite (GB)Mailchimp (Std)
500$10$20
2,500$25$60
5,000$39$100
10,000$73$135
25,000$169$270
50,000$289~$385
Transactional by emails / month — monthly
Emails/moMailerSendMailchimp (Mandrill)*
500Free$20 + plan
5,000$7$20 + plan
25,000~$19$20 + plan
50,000$35$40 + plan
75,000~$59$60 + plan
   

* Mailchimp Transactional (Mandrill) is sold in $20 blocks of 25,000 emails and only works on a paid Standard/Premium plan — so a transactional-only client still drags a $20+ marketing plan along for the ride. The simulator accounts for this.

05 / THE AGENCY CLIENT SIMULATOR

Build your roster. Watch the two bills fight.

Add a client, drag its marketing and transactional needs, and the stack costs recompute live across your whole book. Rename clients, try the presets, stack a dozen. All in-memory — nothing is saved.

agency-stack-simulator · live
Combo / month
$0
$0 / year
Mailchimp / month
$0
$0 / year
You keep
$00%
$0 / year saved · 0 clients

Marketing slider = active contacts (0–50k). Transactional slider = emails/month (0–75k). Combo = MailerLite (Growing Business) + MailerSend, cheapest covering plan. Mailchimp = Standard marketing + Mandrill blocks, with the forced-plan rule applied. Mid-tier numbers are interpolated from listed rates and meant for directional planning, not a quote.