Free-tier email

AgentMail

AgentMail is an email inbox API for AI agents. It provides programmatic creation and management of email inboxes, threads, replies, attachments, realtime events, custom domains, semantic search, and data extraction through REST APIs, SDKs, webhooks, and MCP support.

Antideo

Antideo provides APIs for IP address location, IP reputation, email validation, and phone number validation. The service exposes endpoints for IP geolocation, proxy and blacklist checks, disposable and generic email detection, and phone number validation with country, carrier, and time zone data.

ClankerMails

ClankerMails is a hosted email inbox service for bots and automations. It provides real email addresses that can be created through an API, then polled or monitored for incoming messages without running an email server.

ImprovMX

ImprovMX is an email forwarding service for custom domains. It routes incoming mail to one or more destination addresses, and also offers SMTP sending for outbound mail from the same domain.

Maileroo

Maileroo is an email delivery platform that provides SMTP relay, a REST/HTTP email API, inbound routing, and email marketing tools. The service supports transactional sending from applications or webs...

AhaSend

AhaSend is a transactional email service that provides RESTful APIs and SMTP relay for sending application emails. The platform includes a developer CLI, sandbox mode for testing, webhook and inbound ...

MailerSend

MailerSend is an email sending service that provides an email API, SMTP relay, dynamic email templates, inbound email routing, email verification, user management, multiple domains, DMARC monitoring, ...

MailerLite

MailerLite is an email marketing platform that provides campaign creation, automation, landing pages, websites, signup forms, pop-ups, and digital product or booking sales. It includes a drag-and-drop...

Mailchimp

Mailchimp is an email and SMS marketing platform with audience management, campaign creation, automations, analytics, and integrations. The pricing page shows a free plan limited to 250 contacts, plus...

Kit

Kit is an email marketing platform for creators that combines email sending, landing pages, forms, audience segmentation, visual automations, recommendations, and commerce features in one hosted servi...

Ghost is an open source publishing platform for websites, blogs, and newsletters. It provides a hosted service and software for creating and managing content, sending email newsletters, and running paid memberships and subscriptions.

Buttondown

Buttondown is a hosted email newsletter platform for creating, sending, and managing mailing lists. It provides a markdown or rich text editor, custom-domain sending, hosted newsletter archives, paid ...

Gro

Gro is a B2B sales automation platform that combines lead discovery, outreach automation, social CRM, and intent scoring. The product searches a 650M+ contact database for verified emails and phone nu...

Mailtrap

Mailtrap is an email delivery platform with two main products: Email API/SMTP for sending transactional and promotional email, and Email Sandbox for testing emails in staging, dev, and QA environments...

Plunk is an open-source email platform for transactional email, marketing campaigns, and workflow automation. It provides a REST API, SDKs for Node.js and Python, custom domains with DKIM, inbound ema...

beehiiv

beehiiv is a newsletter platform that combines newsletter publishing, website building, audience growth, analytics, and monetization tools in one hosted service. It includes a drag-and-drop editor, cu...

Postmark

Postmark is an email delivery service that exposes both an Email API and SMTP service for sending transactional and broadcast email. The platform also includes inbound email processing, message streams, templates, webhooks, analytics, and official SDKs for common languages and frameworks.

SendGrid

Twilio SendGrid provides an Email API and SMTP service for sending transactional and application email, along with marketing campaign tools for creating and managing email campaigns. The product is pr...

Mailmodo is an AI-powered email marketing platform that helps businesses create, automate, and optimize campaigns from a single workspace. It combines campaign creation, journey automation, audience s...

Zero Email is an AI-native email client designed to help users manage their inbox more efficiently. It combines AI-powered chat, automated labeling, writing assistance, and instant thread summaries with a keyboard-first interface built for fast email processing.

Loops

Loops is an email platform built for product, marketing, and transactional messaging in one place. It helps teams send lifecycle emails, campaigns, and system-driven messages while keeping email design, audience data, and automation connected to the product.

Mailjet

Mailjet is an email marketing and email API platform for teams that need to design, send, and manage both marketing and transactional email. It combines a collaborative email editor with developer-fri...

Brevo

Brevo is an AI-powered customer platform for marketing, sales, CRM, and customer engagement. It brings together email marketing, SMS, WhatsApp, push notifications, live chat, chatbot, transactional messaging, and loyalty tools in a single platform.

Resend

Resend is an email platform for developers that helps teams send transactional and marketing email at scale. It provides a modern API-first workflow with SDKs, SMTP, REST access, and React Email support so developers can integrate email delivery directly into their applications.

Amazon SES

Amazon Simple Email Service (Amazon SES) is a cloud-based email service provider for sending and receiving email at scale. It is designed for transactional messages, marketing campaigns, newsletters, ...

Abstract Email Validation API

Abstract API’s Email Validation and Verification API provides real-time email verification designed to help teams reduce bounce rates, clean signup forms, and improve the quality of inbound leads. It ...