Best Email API Products in 2025

The best way to send transactional emails directly from your code.

freemium

Flagsmith lets you manage feature flags and remote config across web, mobile and server side applications. Deliver true Continuous Integration. Get builds out faster. Control who has access to new features. We're Open Source.

Key Flagsmith features:

Feature Flags Remote Config A/B/X Testing & Optimization Organization Management

Try for free Open Source freemium

Email for developers.

Key Resend features:

Ease of Use API Flexibility Deliverability Scalability

Affordable Email Marketing Software. Get all features (Segmentation, Automation, A/B testing) for up to 1,000 subscribers & send unlimited emails for free!

Key MailerLite features:

User-Friendly Interface Affordable Pricing Rich Feature Set Email Deliverability

Innovative online Email Marketing solution to manage your contacts, create & send your newsletters and track your results. More than 80 000 clients. Best prices and attractive features.

Key Brevo features:

User-Friendly Interface Comprehensive Analytics Customization Options Automation Features

MailChimp is the best way to design, send, and share email newsletters.

Key MailChimp features:

Ease of Use Automation Features Comprehensive Reporting Integrations

The email delivery platform you can rely on.

Key Flowmailer features:

Deliverability Tracking and Analytics Integration Customization

Send email directly from your client-side Javascript code – no server side code required. Add static or dynamic attachments, dynamic parameters, captcha code and more. Start with our free tier!

Key EmailJS features:

No Server Code Required Integration with Multiple Services Ease of Use Free Tier Availability

Tarvent makes email marketing and automation easier than ever. We are designed to be the easiest and most intuitive email marketing platform available, offered at a price everyone can afford.

Key Tarvent features:

Everything plan Email sends Users File storage

paid Free Trial $16.0 / Monthly (500 contacts, unlimited sending domain, unlimited journeys)

Learn why more developers choose SendGrid for their email deliverability service to send transactional emails triggered by web apps. Get started for free.

Key SendGrid features:

Scalability API Integration Deliverability Analytics

All-in-one email service provider that provides maximum insight and deliverability results for both marketing and transactional emails.

Key Mailjet features:

User-Friendly Interface Real-Time Analytics API Integration Template Management

Add email marketing to your SaaS app in hours, not months.

Key Cakemail features:

User-Friendly Interface Cost-Effective Plans Automation Features Template Library

freemium $8.0 / Monthly (Growth)

SMS API and WhatsApp Business API.

Key AuthKey.io features:

Live Monitoring AI Based Routing Fall Back High Volume API

freemium $13.0 / Monthly

Reduce bounce rates, improve deliverability, and protect your sender reputation with real-time email validation tool.

Key Mailerio features:

Real-Time Email Validation API Bulk Upload Email Lists Single Email Validation Whitelist

paid Free Trial $7.0 (per 1000 email validations)