email-testing

An email and SMTP testing tool with API for developers

Awesome Opensource Email Resources

Mailosaur email and SMS testing commands for Cypress

Self-hosted inbound email infrastructure with a high-performance C++ SMTP ingestion engine, local storage, and developer APIs.

Local SMTP testing made easy

Mailosaur email and SMS testing library for Node.js

Realistic email testing server in a single Docker container. SMTP, IMAP, DKIM/DMARC, spam filtering, REST API, Node/Python SDKs, and an MCP server.

A cross-platform desktop app for catching and viewing emails during development. Built with Laravel, NativePHP & Filament.

Self-hostable disposable email with an API your tests can actually use: private inboxes, wait-for-mail, OTP extraction, webhooks.

Mailosaur email and SMS testing library for Java

Mailosaur Ruby Client Library

A Laravel mail driver that stores outgoing mail in your database, plus a mailbox to read it.

CLI for email compatibility analysis - analyze, preview, audit, and fix HTML emails across 15 clients from the terminal.

Mailosaur email and SMS testing library for Python

Email compatibility engine - analyze HTML against 250+ CSS rules across 15 clients, score compatibility, detect spam, check accessibility, simulate dark mode.

📫 The Post. A modern mail server & utilities. Ships with a CLI, library, and UI.

ManyMail Sandbox SMTP is an open-source project designed for developers to self-host a mail server for testing purposes. It offers features like concurrent SSL, TLS, and unauthenticated servers, a web interface for reading emails, and an API for programmatic email management.

MCP server for email compatibility analysis - preview, audit, fix, diff, and check deliverability across 15 email clients.

My Starter Mail Module - send Mails With html templates using thymeleaf engin

Mailisk library for Cypress