E-mail

Complete solutions

Simple deployment of a mail server, e.g. for inexperienced or impatient admins.

  • docker-mailserver – Fullstack but simple mail server (smtp, imap, antispam, antivirus, etc.). Only configuration files, no SQL database. Keep it simple and versioned. Easy to deploy and upgrade. MIT Docker
  • Inboxen – Inboxen is a service that provides you with an infinite number of unique inboxes. (Source Code) GPL-3.0 Python
  • homebox – Suite of Ansible scripts to deploy a fully functional mail server on Debian. Unobtrusive and automatic as much as possible, focusing on stability and security. GPL-3.0 Shell
  • iRedMail – Full-featured mail server solution based on Postfix and Dovecot. (Source Code) GPL-3.0 Shell
  • Mailcow – Mail server suite based on Dovecot, Postfix and other open source software, that provides a modern Web UI for administration. (Source Code) GPL-2.0 PHP
  • Mailu – Mailu is a simple yet full-featured mail server as a set of Docker images. (Demo, Source Code) MIT Docker/Python
  • Mail-in-a-Box – Turns any Ubuntu server into a fully functional mail server with one command. (Source Code) CC0-1.0 Shell
  • Modoboa – Modoboa is a mail hosting and management platform including a modern and simplified Web User Interface. (Source Code) MIT Python
  • Qmailtoaster – Stable, full-featured, easy-to-install mail server based on qmail. (Source Code) Multiple Linux
  • Simple NixOS Mailserver – Complete mailserver solution leveraging the Nix Ecosystem. GPL-3.0 Nix
  • wildduck – Scalable no-SPOF IMAP/POP3 mail server. (Source Code) EUPL-1.2 Node.js

Mail Transfer Agents

MTAs / SMTP servers

  • chasquid – SMTP (email) server with a focus on simplicity, security, and ease of operation. (Source Code) Apache-2.0 Go
  • Courier MTA – Fast, scalable, enterprise mail/groupware server providing ESMTP, IMAP, POP3, webmail, mailing list, basic web-based calendaring and scheduling services. (Source Code) GPL-3.0 C
  • Exim – Message transfer agent (MTA) developed at the University of Cambridge. (Source Code) GPL-3.0 C
  • Haraka – High-performance, pluginable SMTP server written in Javascript. (Source Code) MIT Javascript
  • MailCatcher – Ruby gem that deploys a simply SMTP MTA gateway that accepts all mail and displays in web interface. Useful for debugging or development. (Source Code) MIT Ruby
  • Maildrop – Disposable email SMTP server, also useful for development. MIT Scala
  • MailHog – Small Golang executable which runs an SMTP MTA gateway that accepts all mail and displays in web interface. Useful for debugging or development. MIT Go
  • OpenSMTPD – Secure SMTP server implementation from the OpenBSD project. (Source Code) ISC C
  • Postfix – Fast, easy to administer, and secure Sendmail replacement. IPL-1.0 C
  • Qmail – Secure Sendmail replacement. (Source Code) CC0-1.0 C
  • Sendmail – Message transfer agent (MTA). Sendmail C
  • Slimta – Mail Transfer Library built on Python. (Source Code) MIT Python

Mail Delivery Agents

MDAs – IMAP/POP3 software

  • Cyrus IMAP/POP3 – Intended to be run on sealed servers, where normal users are not permitted to log in. (Source Code) BSD-3-Clause-Attribution C
  • Dovecot – IMAP and POP3 server written primarily with security in mind. (Source Code) MIT/LGPL-2.1 C
  • Piler – feature rich open source email archiving solution. (Source Code) GPL-3.0 C

Mailing lists and Newsletters

Mailing lists servers and mass mailing software – one message to many recipients.

  • Dada Mail – Web-based list management system that can be used for announcement lists and/or discussion lists. (Source Code) GPL-2.0 Perl
  • Listmonk – High performance, self-hosted newsletter and mailing list manager with a modern dashboard. (Source Code) AGPL-3.0 Go
  • Mail For Good ⚠ – Open source email campaign management tool for nonprofits. BSD-3-Clause Javascript
  • Mailman – The Gnu mailing list server. GPL-3.0 Python
  • Mailtrain – self hosted newsletter application built on Node.js (v5+) and MySQL (v5.5+ or MariaDB). (Source Code) GPL-3.0 Nodejs
  • MailyHerald – Self-hosted Mailchimp alternative that you can easily integrate with your site. Helps you send and manage your application mailings. It support email marketing and conducting the daily stream of notifications you send to your users. (Source Code) LGPL-3.0 Ruby
  • Mautic – Mautic is marketing automation software (email, social and more). (Source Code) GPL-3.0 PHP
  • phpList – Newsletter and email marketing with advanced management of subscribers, bounces, and plugins. (Source Code) AGPL-3.0 PHP
  • Postal – Fully featured open source mail delivery platform for incoming and outgoing e-mail. MIT Ruby
  • Schleuder – GPG-enabled mailing list manager with resending-capabilities. (Source Code) GPL-3.0 Ruby
  • Sympa – Mailing list manager. GPL-2.0 Perl

Webmail clients

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