email-testing

An email and SMTP testing tool with API for developers

Awesome Opensource Email Resources

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

Mailosaur email and SMS testing commands for Cypress

Local SMTP testing made easy

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

Mailosaur email and SMS testing library for Node.js

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

The rendering linter for email, in your terminal and CI. HTML, react.email, mjml and maizzle checked against 255 CSS and HTML features across 21 clients, with file:line positions and exit codes. Offline, no account.

Mailosaur Ruby Client Library

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

The rendering linter for email, in your terminal and CI. HTML, react.email, mjml and maizzle checked against 255 CSS and HTML features across 21 clients, with file:line positions and exit codes for the build.

Mailosaur email and SMS testing library for Python

MCP server for email compatibility analysis: preview, audit, fix, diff, and check deliverability across 21 email clients.

📫 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.

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

Mailisk library for Cypress