The most famous email server - IPL-1.0, C

The first Open-Source high-performance MTA developed from the ground-up for high-volume email sending environments. -…

A modern, high performance, flexible SMTP server - Nodejs

Modern outbound MTA cross platform and extendable server application - Nodejs

A fully featured open source mail delivery platform for incoming & outgoing e-mail

Composable all-in-one mail server - GPLv3, Go

SMTP (email) server with a focus on simplicity, security, and ease of operation - Ruby

A bring-your-own-SMTP-server mail relay with REST API and web UI

Transactional email server with a lovely web interface - AGPLv3, Ruby

A small MTA for home and office use - Linux, UNIX, BSD, C

A user friendly IMAP, SMTP and POP3 server with admin GUI and spam protection. - Windows, AGPLv3, C++

A small SMTP and POP3 server that is easy to configure - Windows, Linux, OpenWrt, GPLv3, C++

Simple Golang SMTP relay/proxy server - MIT, Go

James stands for Java Apache Mail Enterprise Server! - Apache License Version 2.0, Java

Blackhole is an MTA written on top of asyncio, utilising async and await statements that dumps all mail it receives to…

the fake smtp email server for development and testing

mailbox SMTP Server + Web Interface for viewing and testing emails during development.

Disposable webmail server (similar to Mailinator) with built in SMTP, POP3, RESTful servers; no DB required.

Selfhosted trashmail solution - Receive Emails via Web UI, JSON API and RSS feed

Generate RFC-compliant e-mail messages for sending over SMTP. DKIM signed (optionally). - MIT, Python

Modern mail server software for IMAP and POP3. Modern being scalable, Unicode-first, and API-controlled

Dovecot mail server

Cyrus IMAP is an email, contacts and calendar server

James stands for Java Apache Mail Enterprise Server! - Apache License Version 2.0, Java

JSON Meta Application Protocol Specification (JMAP) Specification

James stands for Java Apache Mail Enterprise Server! - Apache License Version 2.0, Java

Go module for interfacing with JMAP servers

Insular email distribution - mail server as Docker images

Open Source Mail Server Solution

A mail suite written in rust meant to be easy to use.

A full featured email service.

Modoboa brings together Open Source's finest in a single interface.

Mail-in-a-Box helps individuals take back control of their email by defining a one-click, easy-to-deploy…

Fullstack, security focused, personal mail server based on OpenSMTPD for OpenBSD ISC License

Production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.) running inside a…

modern full-featured open source secure mail server for low-maintenance self-hosted email - MIT, Go

Secure & Modern All-in-One Mail Server (IMAP, JMAP, POP3, SMTP) - GNU AGPLv3 & Stalwart Enterprise License 1.0 (SELv1)…

All-in-one 100% open-source mail server alternative to Gmail/Mailchimp/Sendgrid (IMAP, POP3, SMTP, CalDAV) - BUSL-1.1…

Fast and privacy-preserving email threat detection with shared intelligence.

Advanced spam filtering system and email processing framework.

AgentJ is a free software anti-spam solution with human authentication and admin panel - AGPL, PHP

Fast Advanced Spam Analysis Tool.

The Anti-Spam SMTP Proxy (ASSP).

Open Source anti-spam platform - Apache License Version 2.0, Perl, C

Full-featured, open-source mail proxy and protects your mail server from spam, viruses, trojans, and phishing emails -…

Anonymous email forwarding

Web and API based SMTP testing - MIT, Go

Catches mail and serves it via a webui - MIT, Ruby

Email test server for development, written in Rust - Apache License, Rust

An email and SMTP testing tool with API for developers - MIT, Go

Debug and development tool for MTA architects! Robin is a highly configurable SMTP client for testing and debugging…

Programmable mail server for apps and AI agents: Haraka-based SMTP (MX + submission), IMAP server, SQLite backend and…

Receive email and sent parsed content/headers to webhook, attachments to S3.

A tool that parses emails by enhancing the Python standard library, extracting all details into a comprehensive…

Python library and supporting utilities to parse and process PST and mbox email sources - MIT, Python

A CLI for verifying email address deliverability over SMTP without sending an email. - AGPL-3.0, Go

Check if an email exists without sending any email. - Dual Licence Commercial/AGPL, Rust

A Go library for email verification without sending any emails. - MIT, Go

Cross-language email validation. Backed by a database of over 55 000 throwable email domains.

PHP Email address validator

Configurable framework agnostic plain Ruby email validator/verifier. Verify email via Regex, DNS, SMTP and even more.…

Verify email address checking MX records, and SMTP connection, check for disposable email addresses and free email…

A robust email syntax and deliverability validation library for Python. The Unlicense, Python

Self-hosted email verification script to clean up bad invalid email address lists. Supports various commercial email…

A high-performance and secure REST/GraphQL API built with Rust, MongoDB & Redis for cleaning email subscriber lists.…

Downloads and flattends datas from Google Postmaster Tools (GPT)

Tool to retrieve @hetrixtools data from their API and store them in flat file or in a database

Open Source Marketing Automation Software

Open-source self-hosted email marketing. Manage your own newsletters at a fraction of the cost.

Open-Source Email Platform - GNU Affero General Public License v3.0, typescript

High performance, self-hosted, newsletter and mailing list manager with a modern dashboard. Single binary app.

Self hosted newsletter app

Keila is an Open Source alternative to newsletter tools like Mailchimp or Sendinblue.

Fully functional Open Source email marketing manager for creating, sending, integrating, and analysing email campaigns…

Mailing platform with templates and logs included. - MIT, php, Laravel

Convert RSS/Atom feed to email newsletters - GNU Affero General Public License v3.0, Python

Notifuse is an open-source & modern emailing platform - GNU Affero General Public License v3.0, go, typescript

GNU AGPLv3, php, symfony, go, SvelteKit, Postgresql

Framework to make responsive-email easy

HTML email development framework

A few simple, but solid patterns for responsive HTML email templates and newsletters. Even in Outlook and Gmail.

HEML is an open source markup language for building responsive email.

Golang package that generates clean, responsive HTML e-mails for sending transactional mail

Compile-time HTML templates for Rust - MIT, Apache License, Rust

Quickly create responsive HTML emails that work on any device and client. Even Outlook. - MIT, HTML

Convert a simple HTML syntax into tables compatible with Foundation for Emails.

Easy to use, yet comprehensive library for sending mails with Ballerina - Apache 2.0, Ballerina

An SMTP client & server library written in Go - MIT, Go

Easy to use, yet comprehensive library for sending mails with Go - MIT, Go

🔏 A Go library and tools for DKIM, DMARC and Authentication-Results - MIT, Go

a mailer library for Rust - MIT, Rust

Rust library to parse mail files - BSD Zero Clause, Rust

Handy email creation and transfer library for PHP with both text and MIME-compliant support.

Library for using online Email providers for PHP

Play mailer plugin for Scala

Mail Analyzing Interface: A library to parse RFC5322 bounce emails and generating structured data as JSON from parsed…

A cross-platform .NET library for IMAP, POP3, and SMTP.

A .NET MIME creation and parser library with support for S/MIME, PGP, DKIM, TNEF and Unix mbox spools.

A Node.js library

The classic email sending library for PHP

Django email backends and webhooks for multiple ESP - BSD 3-Clause, Python

Compose, deliver and test your emails easily in Elixir - MIT, Elixir

Can I email… Support tables for HTML and CSS in emails.

Turns CSS blocks into style attributes BSD 3-Clause, Python

How to target email clients for email development.

List of email CSS normalise/resets.

Write email templates with vue - MIT, Typescript

Lint HTML emails against 250+ CSS properties across 15 email clients: compatibility scoring, dark mode simulation,…

LePatron is an opensource email builder allowing to industrialize your email template production. Build tailor made…

Responsive Email Template Editor

Drag-n-Drop Email Editor Component for React.js

Drag-n-Drop Email Editor Component for Vue.js

Free and Open source Web Builder Framework. Next generation tool for building templates without coding

An open source html email template builder with drag & drop editor

DnD Email Editor based on React.js and MJML.

Paperbits editors and generators for email templates.

Drag and drop HTML email designer - MIT, Typescript

A free and open-source block-based email template builder - MIT, Typescript

A Resend Template-style WYSIWYG email editor with Notion-like editing that generates email-safe React Email templates.…

Craft beautiful emails effortlessly with Maily, the powerful email editor that ensures impeccable communication across…

Render markdown into email-safe HTML - MIT, Typescript

Convert MDX files to HTML emails, fast! - MIT, Javascript

Collaborative messaging solution

The Roundcube Webmail suite - GPLv3, PHP

Tutanota is an email service with a strong focus on security and privacy that lets you encrypt emails, contacts and…

The mailserver suite with the 'moo' – 🐮 + 🐋 = 💕

Cypht: Lightweight Open Source webmail written in PHP and JavaScript - GNU Lesser General Public License v2.1, PHP,…

Web based groupware server written in PHP - GPLv2, PHP

CLI to manager email - MIT, Rust

Scan domains and return data based on trustworthy email best practices

Another utility to analyze state of deployment of security-related email protocols.

E-Mail Header Analyzer

Scan domains and receive advice based on their BIMI, DKIM, DMARC, and SPF records - Apache License version 2.0, Go

A web application that allows the users to check whether their SPF, DMARC and DKIM configuration is set up correctly.…

mxcheck is an info and security scanner for e-mail servers. GPL v-3, Go

CLI to query Spamhaus Intelligence API GPL v-3, Python

A Python package and CLI for parsing aggregate and forensic DMARC reports - Apache License version 2.0, Python

Convert DMARC report files from xml to human-readable formats

Open DMARC Analyzer is an Open Source DMARC Report Analyzer to be used with DMARC reports that have been parsed by…

A php parser, viewer and summary report generator for incoming DMARC reports.

A Perl based tool to parse DMARC reports from an IMAP mailbox or from the filesystem, and insert the information into…

A parser for SPF and DMARC DNS records - Apache License version 2.0, Python

DMARC & SMTP-TLS Reports processor and visualizer and BIMI file hoster - GPL v2, PHP

Self-hosted DMARC aggregate report monitoring with per-client dashboards and multi-tenant separation; also ingests…

Parses DMARC aggregate reports from XML, .xml.gz and .zip and extracts them from report email. Runs on Deno, Node.js,…

Protect your online identity with email alias

a list of disposable and temporary email address domains - Public Domain, Python

Disposable email domain lists, used in disposable email services, generated every quarter of an hour, in txt and JSON…

A list of disposable/temporary email address domains - MIT, Python

Anti-cheating, temporary (disposable/throwaway) email list - MIT, Javascript

This project is a compilation of datasets related to emails. Includes disposable emails, disposable domains, and free…

A list of disposable email domains, cleaned and validated by scanning MX records. - MIT, Python

Daily-refreshed master list of ~162,000 disposable/temporary email domains, plus role-account local-parts and verified…

Thunderbird extension for managing emails with expiration dates - GPL v-3, Javascript

Imapsync is an IMAP transfers tool. The purpose of imapsync is to migrate IMAP accounts or to backup IMAP accounts.…

Self-hosted AI brain for email that synchronizes IMAP mailboxes into PostgreSQL and provides lexical and semantic…