Open Source Email Software

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.

Simple, web-based address & phone book, contact manager, organizer. Groups, addresses, e-Mails, phone numbers & birthdays. vCards, LDIF, Excel, iPhone, Gmail & Google-Maps supported. PHP / MySQL based.

Mailman is the GNU mailing list manager. It provides standard list management features, integrated with a web interface. Please note: the subversion repository has been retired. Please see http://wiki.list.org/x/DgAJ for details.

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

Mail Notifier is free, modern email notifier with the latest user interface trends for Windows 10/11. It supports multiple accounts and IMAP/POP3 protocols. Enjoy customizable notifications, message previews, and more, all in 34 languages! For more details, please refer to the readme.txt file (Files tab, description below). Note: Gmail support is currently unavailable due to verification requirements by Google. Note: Outlook.com support is currently unavailable due to moving to OAuth2 authentication from login/password at Outlook servers.

Thunderbird-Tray is a system tray launcher tool for Mozilla Thunderbird, the popular e-mail client. You can use TB-Tray to hide Thunderbird to the tray while you don't need it. When you click the tray icon, TB-Tray will restore Thunderbird.

The Mailredirect extension for Mozilla Thunderbird and Mozilla SeaMonkey adds the ability to redirect one or more email messages to one or more recipients. The feature of email redirecting is also known as remailing or resending. The extension is an answer for https://bugzil.la/12916

ClamMail is POP3 email proxy for Windows with integrated ClamAV antivirus engine. ClamMail is an Windows antivirus that protects your PC from viruses transferred via mail. Works with Outlook,Thunderbird,Eudora and many others using popular POP3 protocol

EGroupware has moved to Github, please find all our downloads there: https://github.com/EGroupware/egroupware/releases EGroupware is a multi-user, web-based groupware suite. Currently available modules include: email, addressbook, calendar, infolog (notes, to-do's, phone calls), content management, wiki, project management, tracker, timesheet, knowledge base, CalDAV/CardDAV

Webmail with support for MIME mail, address book, plugin system, differrent themes and languages. Runs on PHP, MySQL and connects to IMAP servers.

Roundcube Webmail is a browser-based, multilingual IMAP client with an application-like user interface. Roundcube provides the full functionality you'd expect from an email client, including MIME support, address book, folder manipulation, message searching, and spell check. Roundcube is written in PHP and JavaScript.

NETOFFICE EIS: CRM/SRM Corporate AddressBook ; iCAL Corporate Calendar + Agenda ; eMSG MailBox Email + Fax Messagery ; DMS FileManager + Document Management ; EXTM ModExpress (modules / extra apps: financial, sales) ; CPanel administration ; Intercha