Awesome Opensource Email Resources

A curated list of resources on Email tools, server, framework, technology...

Sweego is a multichannel notification platform for developers

Mindbaz is an email marketing service provider

• Sending
  • SMTP Server
  • Email Testing Application
  • IMAP/POP Server
  • JMAP Server & others
  • Complete Email Server
  • SPAM Filtering
  • Inbox API
  • Forwarding
  • SMTP Testing
  • Inbound
• Deliverability
  • Email Verification
  • Reputation
• Email Platform
  • Marketing Platform
  • Newsletter Platform
• Code
  • Framework
  • Templating
  • Library
  • Other
• Editing
  • Email Builder & Visual Editing Component
• Email Solution
  • Groupware / Webmail
  • CLI
• Security
  • Security Check
  • DMARC
  • Privacy
• Disposable emails domain list

• Postfix - The most famous email server - IPL-1.0, C
• KumoMTA - The first Open-Source high-performance MTA developed from the ground-up for high-volume email sending environments. - Rust, Lua
• Haraka - A modern, high performance, flexible SMTP server - Nodejs
• Zone-MTA - Modern outbound MTA cross platform and extendable server application - Nodejs
• Postal - A fully featured open source mail delivery platform for incoming & outgoing e-mail
• Maddy - Composable all-in-one mail server - GPLv3, Go
• Chasquid - SMTP (email) server with a focus on simplicity, security, and ease of operation - Ruby
• MailWhale - A bring-your-own-SMTP-server mail relay with REST API and web UI
• Cuttlefish - Transactional email server with a lovely web interface - AGPLv3, Ruby
• DragonFly - A small MTA for home and office use - Linux, UNIX, BSD, C
• hMailServer - A user friendly IMAP, SMTP and POP3 server with admin GUI and spam protection. - Windows, AGPLv3, C++
• EmailRelay - A small SMTP and POP3 server that is easy to configure - Windows, Linux, OpenWrt, GPLv3, C++
• SMTPRelay - Simple Golang SMTP relay/proxy server - MIT, Go
• James - James stands for Java Apache Mail Enterprise Server! - Apache License Version 2.0, Java

• Blackhole - Blackhole is an MTA written on top of asyncio, utilising async and await statements that dumps all mail it receives to /dev/null.
• SMTP4dev - the fake smtp email server for development and testing
• Maildev - mailbox SMTP Server + Web Interface for viewing and testing emails during development.
• Inbucket - Disposable webmail server (similar to Mailinator) with built in SMTP, POP3, RESTful servers; no DB required.
• Opentrashmail - Selfhosted trashmail solution - Receive Emails via Web UI, JSON API and RSS feed
• TestMSG - Generate RFC-compliant e-mail messages for sending over SMTP. DKIM signed (optionally). - MIT, Python

• Wildduck - Modern mail server software for IMAP and POP3. Modern being scalable, Unicode-first, and API-controlled
• Dovecot - Dovecot mail server
• Cyrus - Cyrus IMAP is an email, contacts and calendar server
• James - James stands for Java Apache Mail Enterprise Server! - Apache License Version 2.0, Java

• JMAP - JSON Meta Application Protocol Specification (JMAP) Specification
• James - James stands for Java Apache Mail Enterprise Server! - Apache License Version 2.0, Java
• Gomap - Go module for interfacing with JMAP servers

• Mailu - Insular email distribution - mail server as Docker images
• iRedMail - Open Source Mail Server Solution
• Erooster Email Server - A mail suite written in rust meant to be easy to use.
• Zimbra Open Source Edition - A full featured email service.
• Modoboa - Modoboa brings together Open Source's finest in a single interface.
• Mailinabox - Mail-in-a-Box helps individuals take back control of their email by defining a one-click, easy-to-deploy SMTP+everything else server: a mail server in a box.
• Excision-Mail - Fullstack, security focused, personal mail server based on OpenSMTPD for OpenBSD ISC License
• Docker Mailserver - Production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.) running inside a container. - MIT
• Mox - modern full-featured open source secure mail server for low-maintenance self-hosted email - MIT, Go
• Stalwart - Secure & Modern All-in-One Mail Server (IMAP, JMAP, POP3, SMTP) - GNU AGPLv3 & Stalwart Enterprise License 1.0 (SELv1) Agreement, Rust
• Forward Email - All-in-one 100% open-source mail server alternative to Gmail/Mailchimp/Sendgrid (IMAP, POP3, SMTP, CalDAV) - BUSL-1.1 & MPL-2.0, JavaScript

• Rspamd - Advanced spam filtering system and email processing framework.
• AgentJ - AgentJ is a free software anti-spam solution with human authentication and admin panel - AGPL, PHP
• Spamscope - Fast Advanced Spam Analysis Tool.
• ASSP - The Anti-Spam SMTP Proxy (ASSP).
• Spamassassin - Open Source anti-spam platform - Apache License Version 2.0, Perl, C
• Proxmox Mail Gateway - Full-featured, open-source mail proxy and protects your mail server from spam, viruses, trojans, and phishing emails - GNU AGPLv3

• Anonaddy - Anonymous email forwarding

• MailHog - Web and API based SMTP testing - MIT, Go
• MailCatcher - Catches mail and serves it via a webui - MIT, Ruby
• MailCrab - Email test server for development, written in Rust - Apache License, Rust
• MailPit - An email and SMTP testing tool with API for developers - MIT, Go
• Robin - Debug and development tool for MTA architects! Robin is a highly configurable SMTP client for testing and debugging SMTP servers. - Java, Apache License 2.0

• Inbound SMTP to Webhook - Receive email and sent parsed content/headers to webhook, attachments to S3.
• Mail-Parser - A tool that parses emails by enhancing the Python standard library, extracting all details into a comprehensive object. Apache License 2.0, Python

• CustomerOS MailSherpa - A CLI for verifying email address deliverability over SMTP without sending an email. - AGPL-3.0, Go
• Reacher - Check if an email exists without sending any email. - Dual Licence Commercial/AGPL, Rust
• Email-Verifier - A Go library for email verification without sending any emails. - MIT, Go
• Mailchecker - Cross-language email validation. Backed by a database of over 55 000 throwable email domains.
• EmailValidator - PHP Email address validator
• Truemail - Configurable framework agnostic plain Ruby email validator/verifier. Verify email via Regex, DNS, SMTP and even more. Be sure that email address valid and exists. - MIT, Ruby
• email-validator-js - Verify email address checking MX records, and SMTP connection, check for disposable email addresses and free email providers. - MIT, Typescript
• python-email-validator - A robust email syntax and deliverability validation library for Python. The Unlicense, Python
• validate-email - Self-hosted email verification script to clean up bad invalid email address lists. Supports various commercial email verification provider APIs all in one script - PHP

• Google Postmaster Datas - Downloads and flattends datas from Google Postmaster Tools (GPT)
• Python Hetrixtools Blacklist - Tool to retrieve @hetrixtools data from their API and store them in flat file or in a database

• Mautic - Open Source Marketing Automation Software
• Sendportal - Open-source self-hosted email marketing. Manage your own newsletters at a fraction of the cost.
• Ferdinand - Open-source email delivery service for developers. GNU Affero General Public License v3.0, templ, javascript, Go
• Plunk - Open-Source Email Platform - GNU Affero General Public License v3.0, typescript

• Listmonk - High performance, self-hosted, newsletter and mailing list manager with a modern dashboard. Single binary app.
• Mailtrain - Self hosted newsletter app
• Keila - Keila is an Open Source alternative to newsletter tools like Mailchimp or Sendinblue.
• phplist3 - Fully functional Open Source email marketing manager for creating, sending, integrating, and analysing email campaigns and newsletters.
• MailCarrier - Mailing platform with templates and logs included. - MIT, php, Laravel
• RSS2Newsletter - Convert RSS/Atom feed to email newsletters - GNU Affero General Public License v3.0, Python
• Notifuse - Notifuse is an open-source & modern emailing platform - GNU Affero General Public License v3.0, go, typescript

• MJML - Framework to make responsive-email easy
• Maizzle - HTML email development framework

• Cerberus - A few simple, but solid patterns for responsive HTML email templates and newsletters. Even in Outlook and Gmail.
• HEML - HEML is an open source markup language for building responsive email.
• Hermes - Golang package that generates clean, responsive HTML e-mails for sending transactional mail
• Maud - Compile-time HTML templates for Rust - MIT, Apache License, Rust
• Foundation for Emails 2 - Quickly create responsive HTML emails that work on any device and client. Even Outlook. - MIT, HTML
• Inky - Convert a simple HTML syntax into tables compatible with Foundation for Emails.

• ballerina-email - Easy to use, yet comprehensive library for sending mails with Ballerina - Apache 2.0, Ballerina
• go-smtp - An SMTP client & server library written in Go - MIT, Go
• go-mail - Easy to use, yet comprehensive library for sending mails with Go - MIT, Go
• go-msgauth - 🔏 A Go library and tools for DKIM, DMARC and Authentication-Results - MIT, Go
• lettre - a mailer library for Rust - MIT, Rust
• mailparse - Rust library to parse mail files - BSD Zero Clause, Rust
• Nette Mail - Handy email creation and transfer library for PHP with both text and MIME-compliant support.
• Stampie - Library for using online Email providers for PHP
• Play-Mailer - Play mailer plugin for Scala
• Sisimai - Mail Analyzing Interface: A library to parse RFC5322 bounce emails and generating structured data as JSON from parsed results. For Perl, Go & Ruby
• MailKit - A cross-platform .NET library for IMAP, POP3, and SMTP.
• MimeKit - A .NET MIME creation and parser library with support for S/MIME, PGP, DKIM, TNEF and Unix mbox spools.
• Nodemailer - A Node.js library
• PHPMailer - The classic email sending library for PHP
• Anymail - Django email backends and webhooks for multiple ESP - BSD 3-Clause, Python
• Swoosh - Compose, deliver and test your emails easily in Elixir - MIT, Elixir

• Can I email - Can I email… Support tables for HTML and CSS in emails.
• Premail - Turns CSS blocks into style attributes BSD 3-Clause, Python
• HowToTarget.email - How to target email clients for email development.
• Email CSS Resets - List of email CSS normalise/resets.

• LePatron - LePatron is an opensource email builder allowing to industrialize your email template production. Build tailor made email templates and make them available to your non-technical users.
• Mosaico - Responsive Email Template Editor
• React Email Editor - Drag-n-Drop Email Editor Component for React.js
• Vue Email Editor - Drag-n-Drop Email Editor Component for Vue.js
• GrapesJS - Free and Open source Web Builder Framework. Next generation tool for building templates without coding
• MySigMail Card - An open source html email template builder with drag & drop editor
• Easy Email - DnD Email Editor based on React.js and MJML.
• Paperbits emails - Paperbits editors and generators for email templates.
• Drag-and-Drop-Email-Designer - Drag and drop HTML email designer - MIT, Typescript
• email-builder-js - A free and open-source block-based email template builder - MIT, Typescript

• Bluemind - Collaborative messaging solution
• Roundcube - The Roundcube Webmail suite - GPLv3, PHP
• Tutanota - Tutanota is an email service with a strong focus on security and privacy that lets you encrypt emails, contacts and calendar entries on all your devices.
• Mailcow - The mailserver suite with the 'moo' – 🐮 + 🐋 = 💕
• Cypht - Cypht: Lightweight Open Source webmail written in PHP and JavaScript - GNU Lesser General Public License v2.1, PHP, Javascript
• Egroupware - Web based groupware server written in PHP - GPLv2, PHP

• Himalaya - CLI to manager email - MIT, Rust

• Trustymail - Scan domains and return data based on trustworthy email best practices
• mailsec-check - Another utility to analyze state of deployment of security-related email protocols.
• E-Mail Header Analyzer - E-Mail Header Analyzer
• Domain Security Scanner - Scan domains and receive advice based on their BIMI, DKIM, DMARC, and SPF records - Apache License version 2.0, Go
• Mailgoose - A web application that allows the users to check whether their SPF, DMARC and DKIM configuration is set up correctly. - BSD 3-Clause "New" or "Revised" License, Python
• mxcheck - mxcheck is an info and security scanner for e-mail servers. GPL v-3, Go
• Spamhaus-Intelligence-API-CLI - CLI to query Spamhaus Intelligence API GPL v-3, Python

• parsedmarc - A Python package and CLI for parsing aggregate and forensic DMARC reports - Apache License version 2.0, Python
• dmarc-report-converter - Convert DMARC report files from xml to human-readable formats
• Open DMARC Analyzer - Open DMARC Analyzer is an Open Source DMARC Report Analyzer to be used with DMARC reports that have been parsed by John Levine's rrdmarc script or techsneeze's dmarcts-report-parser.
• DmarcSrg - A php parser, viewer and summary report generator for incoming DMARC reports.
• dmarcts-report-parser - A Perl based tool to parse DMARC reports from an IMAP mailbox or from the filesystem, and insert the information into a database. ( Formerly known as imap-dmarcts ) - GNU GPL v3, Perl
• checkdmarc - A parser for SPF and DMARC DNS records - Apache License version 2.0, Python
• Viesti-Reports - DMARC & SMTP-TLS Reports processor and visualizer and BIMI file hoster - GPL v2, PHP

• SimpleLogin - Protect your online identity with email alias

• disposable-email-domains - a list of disposable and temporary email address domains - Public Domain, Python
• disposable-email-domains (another one) - Disposable email domain lists, used in disposable email services, generated every quarter of an hour, in txt and JSON format. - MIT, PHP
• disposable - A list of disposable/temporary email address domains - MIT, Python
• disposable-email-domains (another one too) - Anti-cheating, temporary (disposable/throwaway) email list - MIT, Javascript
• email_data - This project is a compilation of datasets related to emails. Includes disposable emails, disposable domains, and free email services. - MIT, Ruby
• disposable-email-domain-list - A list of disposable email domains, cleaned and validated by scanning MX records. - MIT, Python