Rainloop Webmail - Simple, modern & fast web-based email client

•    PHP

Simple, modern & fast web-based email client.Modest system requirements, decent performance, simple installation and upgrade, no database required - all these make RainLoop Webmail a perfect choice for your email solution.

SharpWebMail - ASP.NET Webmail Application

•    CSharp

SharpWebMail is an ASP.NET webmail application that is written in C#. It uses a POP3 or IMAP servers as the mailstore and sends mail through a SMTP server. It is very simple to configure (only a few settings in the web.config file). You can compose HTML messages, search your inbox, read complex mime messages, have multiple address books and much more.

Hastymail - IMAP/SMTP client in PHP

•    PHP

Hastymail is a fast, secure, rfc-compliant, cross-platform IMAP/SMTP client application written in PHP providing a clean web interface for sending and reading E-mail. It is compatible with PDAs, phones, text browsers, and all mainstream browsers. The ability to use a database for storing user settings, contacts, and plugin data, with support for both Postgresql and Mysql.

Cypht - Lightweight Open Source webmail written in PHP and JavaScript

•    PHP

All your E-mail, from all your accounts, in one place. Cypht is not your father's webmail. Unless you are one of my daughters, in which case it is your father's webmail. Cypht is like a news reader, but for E-mail. Cypht does not replace your existing accounts - it combines them into one. And it's also a news reader..

Mailspring - A beautiful, fast Webmail

•    Javascript

Mailspring is built on the modern web with Electron, React, and Flux. It is designed to be extensible, so it's easy to create new experiences and workflows around email.

SquirrelMail - Webmail

•    PHP

SquirrelMail is a PHP-based Web email client. It includes built-in pure PHP support for IMAP and SMTP, and renders all pages in pure HTML 4.0 for maximum compatibility across browsers. It has strong MIME support and a flexible plugin system.

ProtonMail - Web client for the ProtonMail secure email service

•    Javascript

ProtonMail provides secure email service. All emails are secured automatically with end-to-end encryption. This means even we cannot decrypt and read your emails. As a result, your encrypted emails cannot be shared with third parties.

yawebmail - yet another webmail client

•    Java

A webmail-client (POP3, IMAP, SMTP) written in Java as a webapp. Very easy to install - just throw the WAR-file into the deployment-directory of your Servlet-container (tomcat, jetty, weblogic, ..) and you're ready! Test ride on the yawebmail-Homepage!

Simple WebMail

•    PHP

Simple Webmail is front end Web of mail, programmed in php, uses imap and smtp. It was developed under Linux and Apache with ModPHP. El proyecto se encuentra discontinuado pero dejo los fuentes publicado por si le sirven a alguien.

Roundcube Webmail - Browser-based multilingual IMAP client

•    PHP

Roundcube Webmail is a browser-based multilingual IMAP client with an application-like user interface. It provides full functionality you expect from an email client, including MIME support, address book, folder management, message searching and spell checking.

DavMail - POP/IMAP/SMTP/Caldav to Exchange

•    Java

DavMail is a POP/IMAP/SMTP/Caldav/Carddav/LDAP exchange gateway allowing users to use any mail/calendar client (e.g. Thunderbird with Lightning or Apple iCal) with an Exchange server, even from the internet or behind a firewall through Outlook Web Access. DavMail now includes an LDAP gateway to Exchange global address book and user personal contacts to allow recipient address completion in mail compose window and full calendar support with attendees free/busy display.

James - Enterprise Mail Server

•    Java

James (a.k.a Java Apache Mail Enterprise Server) is a 100% pure Java SMTP and POP3 Mail server, and NNTP News server designed to be a complete and portable enterprise mail/messaging engine solution based on currently available open messaging protocols.

V-webmail

•    PHP

V-webmail is a powerful PHP based webmail application with an abundance of features, including: Easy installation and configuration - Full support for attachments and HTML mail - Folder support (IMAP) - Filtering support (IMAP) - Quick search etc.

FortMail

•    Java

Complete self-contained email server including IMAP, POP3, SMTP, Webmail, mailing lists.

CsWebmail

•    PHP

CsWebmail - yet another webmail application written on PHP for CS department of BGU university with IMAP/NNTP/SMTP support. CsWebmail includes next features: address book,procmail interface,backup,WYSIWYG compose,messages threading etc.

CaMail - Free Modular Webmail

•    Perl

CaMail is a web based mail system written in Perl (using Apache mod_perl) and Template Toolkit. It supports multiple IMAP/SMTP servers along multiple domains and addressbook via LDAP. In adition, LDAP is used to store sessions, groups, message filters

ClearOS - Linux based Operating System

•    C

ClearOS is a powerful network and gateway server designed for small organizations and distributed environments. The open source revolution in the software industry has made it possible to provide ClearOS at no cost. Among other features, antivirus, antispam, VPN and content filtering are built right into the software -- no need for expensive third party add-ons. With ClearOS, you can avoid costly vendor lock-in and proprietary formats; instead, you can embrace open standards and protocols.

sync-engine - :incoming_envelope: IMAP/SMTP sync system with modern APIs

•    Python

The Nylas Sync Engine provides a RESTful API on top of a powerful email sync platform, making it easy to build apps on top of email. See the full API documentation for more details.Install the latest versions of VirtualBox and Install Vagrant.

MailWare Collaboration Suite

A web Collaboration Suite with webmail, calendar, addressbook and chat, based on standard protocols: LDAP, IMAP, SMTP, XMMP. Enjoy the demo at http://www.mailware.it/it/demo.html

Squirrelmail Outlook Skin Theme

•    PHP

SquirrelOutlook is a standards-based webmail package written in PHP4 (Squirrelmail). It includes built-in pure PHP support for the IMAP and SMTP protocols, and all pages render in pure HTML 4.0 for maximum compatibility across browsers.