How much does Customer.io cost?

Customer.io's entry-level Essentials plan starts at $100 per month and includes 5,000 profiles and 1 million emails per month. Billing is based on the maximum number of uniquely identified profiles in the account during the month, with overage charges of roughly $0.009 per additional profile and $0.12 per 1,000 emails beyond plan limits. The Premium plan starts around $1,000 per month on an annual contract and adds managed deliverability, dedicated IPs, and HIPAA compliance with a signed BAA, while Enterprise pricing is custom.

What programming languages does MailerSend have SDKs for?

MailerSend publishes official libraries for PHP (including a dedicated Laravel package), Node.js, Go, Python, Ruby, and Java. Its REST API and SMTP relay can be used from any language, and its documentation does not list an official .NET SDK.

Can I use Customer.io and MailerSend together?

Yes. Many teams route different message types through different providers or fail over between them. Courier lets you send through both behind a single API and switch providers without changing your code.

Customer.io vs MailerSend

Two transactional email providers, compared on price, features and ratings, so you can pick fast.

Customer.io wins compliance and analyticsMailerSend wins price and developer experience

Updated October 2026

At a glanceCustomer.ioMailerSend

G2 rating4.44.1

Trustpilot3.24.0

Drag-and-drop editorYesYes

THE VERDICT

Customer.io wins on compliance and analytics. MailerSend wins on price and developer experience.

Customer.io and MailerSend take different pricing approaches. Customer.io rates higher with developers (4.4 vs 4.1 on G2). Pick based on volume and team, and the scorecard below breaks down where each one leads.

Which should you choose?

Pick Customer.io

✓You need behavior-triggered lifecycle messaging across email, push, and SMS

✓You want journeys driven by real-time user/event data and a unified profile

✓You're consolidating marketing automation and transactional messaging

✓You need EU data residency or HIPAA-grade compliance

Pick MailerSend

✓Teams that need EU-hosted transactional email data by default for compliance or customer-trust reasons

✓Budget-conscious developers who want a real free tier plus a cheap ($7/mo) entry-level paid plan

✓Teams that want built-in email address verification without adding a separate vendor

✓Apps that need inbound email parsing (support tickets, reply-by-email flows) alongside outbound sending

Set up MailerSend with Courier →

Feature by feature

Winner cells are tinted, green where Customer.io leads, violet where MailerSend does.

capability

Customer.io

MailerSend

Pricing

Starting paid plan

$100/mo

$7/mo

Pricing model

Subscription

Hybrid

Overage

Profile-based pricing: additional profiles $0.009 each; additional emails $0.12 per 1,000 over the plan's bundled allowance; AI credits $10/100K. Email volume does not map to a per-email tier.

$1.50 per 1,000 emails beyond the plan's included allowance

Deliverability

Dedicated IP

Plan-gated

Deliverability tooling

Yes

Automated IP warmup

Yes

Suppression management

Yes

SPF / DKIM / DMARC

Yes

API & sending

Transactional API

Yes

Marketing campaigns

Yes

SMTP relay

Yes

Inbound routing

Yes

Dynamic templates

Yes

Batch send

Yes

Scheduled send

Yes

Developer experience

Official SDKs

Ruby, Python, Node.js, Go, PHP, JavaScript (Web), iOS, Android, React Native, Flutter, Expo

PHP, Laravel, Node.js, Go, Python, Ruby, Java

Event webhooks

Yes

Drag-and-drop editor

Yes

Custom HTML editor

Yes

Email validation

Yes

Log retention

—

Plan-gated: 1 day (Free/Hobby), 7 days (Starter), 30 days (Professional)

Sandbox / test mode

—

Yes

Analytics

Open / click tracking

Yes

Analytics dashboard

Yes

A/B testing

Yes

Plan-gated

Compliance

EU data residency

Yes

SOC 2

Yes

HIPAA

BAA

GDPR

Yes

ISO 27001

Yes

—

Support

Support channels

Community + email (Essentials); chat (Standard); dedicated CSM + technical specialist (Premium/Enterprise)

Limited support on Free; 24/7 email support from Hobby; live chat plus priority support on Starter and Professional; dedicated account manager on Professional

24/7 support

—

Yes

Support SLA

Plan-gated

—

Migration assistance

Yes

Plan-gated

FAQ

Common questions

Customer.io rates higher on G2 (4.4 vs 4.1). Ratings are aggregated from public review platforms as of the date shown.

Keep comparing

Related comparisons

Customer.io vs PostmarkEmail→Customer.io vs MailgunEmail→Customer.io vs SendGridEmail→AWS SES vs Customer.ioEmail→Customer.io vs SparkPostEmail→Customer.io vs OneSignal EmailEmail→

Why not both?

Use both behind one API.

Route Customer.io, MailerSend, or both, and switch providers without changing your code. Courier sits in front of every channel.

Start building free Read the docs

Pricing, plans and feature availability as of October 2026 and may change. Ratings are aggregated from public review platforms.