Open Source BSD Email Clients

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.

Trojitá, a Qt IMAP e-mail client

OpenChange is a portable Open Source implementation of Microsoft Exchange server and Exchange protocols. It provides a complete solution to interoperate with Microsoft Outlook clients or Microsoft Exchange servers. OpenChange client-side library is used in existing messaging clients and is the solution in new projects to communicate natively with Microsoft Exchange and Exchange-compatible servers. OpenChange server is a transparent Microsoft Exchange server replacement using native Exchange protocols and does not require any plugin installation in Outlook.

AlphaMail is an accelerated web mail interface with a C++ middleware layer that is more effective than an IMAP proxy which is a highly scalable (10k+ users). The interface includes modern features, Section 508 compliance, and universal browser support.

Columba is an email client written in Java, featuring a user-friendly graphical interface with wizards and internalionalization support. Its a powerful mail management tool with features to enhance your productivity and communication.

PHP app to access Gmail/Googlemail/Gmail-for-Your-Domain accounts on wireless devices. Convenient alternative access method to your email account on the move, gmail-mobile incorporates as many Gmail features as possible within limits of a mobile device.

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. This version of Hastymail is no longer being developed. We are now working on a new version, Hastymail 3, AKA, "Cypht". http://cypht.org

MultiMail is an offline mail packet reader for Unix and other systems. It currently supports the Blue Wave, QWK, OMEN, OPX and SOUP formats. It has a full screen, color user interface, built with the curses library.

Proton Web Clients is a monorepo hosting the web applications for Proton’s suite of privacy-focused services, including the core Proton Mail webmail interface and related web apps like Proton Calendar, Proton Drive, Proton Account, Proton VPN, Proton Pass, and other connected tools. It consolidates all web client code, shared modules, dependencies, and development tooling into a single repository, enabling unified maintenance, consistency of design patterns, and efficient evolution of Proton’s online interfaces. These web clients run entirely in the browser, letting users securely interact with their email, calendars, files, and other services without needing native software installed, and benefiting from end-to-end encryption where applicable. The monorepo includes application logic, UI components, build scripts, and testing infrastructure for reliable deployments and streamlined continuous integration.

Claws Mail is a GTK+ based, lightweight, and fast e-mail client and newsreader. Supports POP3, APOP, IMAP, SMTP, SMTP AUTH, NNTP, LDAP, multiple accounts, spell-checking, addressbook, SSL, GPG, filtering, i18n, & more. It is further extended by plugins.

To provide Polish translation of all Mozilla.org products...

NOCC is a simple and fast Webmail client which can handle POP3 and IMAP mailboxes and sends email via SMTP. It is written with PHP, has low requirements (no database, frames). Features multi-language support, MIME attachments, displays HTML messages. The installation guide comes with the source code: https://sourceforge.net/p/nocc/code/HEAD/tree/trunk/webmail/docs/INSTALL If you encounter problems or bugs you can always try the current HEAD version: https://sourceforge.net/p/nocc/code/HEAD/tarball?path= Questions, bug reports or support requests are very welcome: https://sourceforge.net/p/nocc/_list/tickets Alternative source code repository: https://github.com/oheil/NOCC

MH-E is the Emacs interface to the MH mail system. It offers all the functionality of MH, the visual orientation and simplicity of use of a GUI, and full integration with Emacs, including thorough configuration and online help. Since MH-E 8.6 was released in 2016, its development migrated to the Emacs repository. Thus, if you install an Emacs package, or check out and compile the Emacs source, then you will be running the latest version of MH-E. Consequently, we will retire this site once all of the tickets are resolved. Therefore, please help us out and submit new tickets with M-x report-emacs-bug. MH-E is now only supported in the version of GNU Emacs in which it appears. It is no longer supported in XEmacs. It is compatible with MH versions 6.8.4 and higher, all versions of nmh, and GNU mailutils 1.0 and higher.

Note! Code and issues are maintained at https://github.com/sba1/simplemail. SimpleMail is a simple to use but powerful mail client. It supports the SMTP, POP3 and IMAP (in a simple form) protocols. Furthermore, among much other features, it is capable of showing HTML mails and can identify spam mails by using a Bayesian filter.

zClipse is a project for building Eclipse (http://www.eclipse.org) plugins. Plugins currently being developed include: TabNavigator - editor enhancements; JScheme - Scheme integration; Insectivore - shared TeamTasks, integrated with Tasks view.

Heirloom mailx (formerly known as "nail") is intended provide the functionality of the POSIX mailx command with additional support for MIME messages, IMAP (including caching), POP3, SMTP, S/MIME, message threading/sorting, scoring, and filtering.

iMailist is a software allowing the sending of mails to format HTML to a whole mailing-list. The program is written in Objective-C/Cocoa and works on Mac OS 10.3

BoboMail is a so called webmail application, which provides mail access through a web interface. It handles MIME messages properly (including HTML mails) and is implemented in Python.

GoldBug is a decentralized & secure communication suite that offers an integrated e-mail client, an instant messenger & a file transfer. Also included is an URL-RSS-DB & a p2p web search. Current vers. w/ McEliece Algorithm. GoldBug has been 2013 - 2023 ten years just another Graphical User Interface of the Spot-On Encryption Suite. Main GUI features: Minimal & colorful Interface with Tabs in the East. Microsoft & Qt MinGW deprecated Win32 & for Compiling: ● https://sourceforge.net/p/goldbug/wiki/compiling As Spot-On implemented the minimal GB-concept & Nuvola Icons, GoldBug has now been fully integrated into Spot-On Win64: Just choose Tabs at East & Mini-View in Options - w/ Nuvola Icons of course! Voilá! & Many Thanks, Pro-Files can be found archived at ● current source: https://github.com/textbrowser/spot-on ● EN Manual: https://www.amazon.com/dp/3749435065 ● DE: https://compendio.github.io/goldbug-manual-de/ ● Study: https://www.amazon.com/asin/dp/3750408971

RFC 2425 defines a MIME Content-Type for Directory Information. This library contains necessary methods to parse information blocks arranged in such a manner.

SaltOS is a Business Management solution 100% Cloud Computing. It integrates features like CRM (Customer Relation Management) and ERP (Enterprise Resource Planning). Moreover is it licensed as 100% free software GPL-3.0.

AVA SBS is a collaboration of Open-Source software designed to give small businesses a cost effective server solution with Enterprise capabilities. AVA-SBS gives business an easy to administrate Primary Domain Controller, Print Server, File Server, Email

libgmailer for PHP consists of 2 parts: {GMailer (libgmailer)} a PHP class/library for you to access GMail with PHP with ease. {gmail-lite} a plain HTML only interface of GMail, accessible by any browser on Earth.

JMail is a mail client written in Java. It handles attached files, HTML mails, filters and other stuff... It can be used with a LDAP directory.

Mailcrypt is an Emacs Lisp package which provides a simple interface to public key cryptography with PGP [and now GnuPG!]. Mailcrypt makes strong cryptography a fully integrated part of your normal mail and news handling environment