Open Source Linux Post-Office Software

The Courier mail transfer agent (MTA) is an integrated mail/groupware server based on open commodity protocols such as ESMTP, IMAP, POP3, LDAP, SSL, and HTTP. Courier provides ESMTP, IMAP, POP3, Webmail, calendaring, and mailing list services.

Fetchmail is a mail retrieval daemon that can download messages from POP3, IMAP, ODMR and ETRN-based stores, with SSL/TLS security including certificate verification, and pass downloaded mail to a local SMTP or LMTP server, or a message delivery agent such as maildrop.

A command line utility for synchronizing remote IMAP mailboxes and local maildir-style mailboxes. This is useful for working in disconnected (off-line) mode, such as on a laptop, but also for mirroring mailboxes between servers.

Send SMTP email silently from command line (CLI), or a batch file using Exchange, Gmail, Hotmail, or Yahoo! Plus. Supports XML settings files, variables, or all settings explicitly from the command line. Now supporting Exit Codes for batch file use (will return "0" for successful delivery, or "1" for error delivering) - handle your batch file accordingly.

Rumble is a mail server suite for SMTP (ESMTPSA), HTTP, POP3 and IMAP4v1 with an extensive C/C++ and Lua API for scripting. It comes with support for SSL/TLS, SQLite and MySQL and has a web-based administration and webmail feature. Additional included modules feature greylisting, DNS blacklisting, SpamAssassin support and dynamic performance scaling as well as a multithreaded structure that allows for clustering of multiple servers for one or all domains, and with the ease of the Lua API, you can create your own new server mailing lists, CRM software, e-marketing and other extensions within minutes.

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

Convert Webmail to POP3.Is also included a SMTP/POP3 tunneling system that allow send and receive email in a private network HTTP PROXY based. All connection are plugin based. Over 450 email server supported and tested, GMAIL POP3/SMTP over Proxy Network.

FreePOPs is a webmail to pop3 conversion daemon. It is extensible to support other webmail using the scripting language LUA. See the homepage for supported webmails.

YPOPs! is an application which emulates a POP3/SMTP mail server and provides free POP3 and SMTP access to Yahoo! Mail. It does not depend on Yahoo's POP3/SMTP mail server. You can use a mail client of your choice!

.NET library written in C# with a full implementation of a POP3 client. Easy to use but yet powerful. Includes a robust MIME parser backed by several hundred test cases. The easiest way to install OpenPop.NET is via NuGet. In Visual Studio's Package Manager Console, simply enter the following command: Install-Package OpenPop.NET Our homepage (http://hpop.sourceforge.net/) includes examples, documentation and a general introduction for email. For more information, visit our project homepage. Code is hosted on GitHub (https://github.com/foens/hpop).

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.

OBM is a groupware, email, LDAP, Windows PDC, CRM, and project application mainly used as an Exchange or Notes/Domino replacement with groupware connectors for Outlook, Thunderbird/Lightning, and PDAs. It is highly scalable up to many thousands of users

TEK empowers low-connectivity communities by providing a full Internet experience using email as the transport mechanism.

ZMail allows you to send email from anyone, to anyone. You can use ZMail to send fake or anonymous emails. Have fun!

jwSMTP, Send email programmatically (C++ code/lib). Linux, BSD, Windows etc. Attachments, Multiple recipients, Cc/Bcc recipients supported. MX lookup or send to an SMTP server direct. LOGIN and PLAIN authentication now supported. Html or plain text forma

Highly scalable/configurable Messaging Platform allowing users in a domain to be distributed on multiple hosts, has multiple queues. Provides virtual domains/users in MySQL. Modern MSP class qmail replacement with ESMTP, POP3/IMAP, QMTP, QMQP support

AtMail is an open source webmail client written in PHP. We aim to provide a elegant Ajax webmail client for existing IMAP mailservers, with less bloat and a focus on an intuitive, simple user interface.

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.

Mailcheck is a simple, command line, configurable tool that allows multiple mailboxes to be checked for the existence of new mail messages. It supports both mbox and maildir-style mailboxes. It also supports remote POP3 and IMAP mailboxes.

a small, php based pop3 webmail application.

BitMail is a Proof-of-Concept- / Design-Study for an Qt E-Mail Client. POP3 / IMAP / SMTP / P2P E-Mail-Client. ● Qt E-Mail Client. ● Build-in Encryption to secure E-Mails ● IMAP & POP3 ● Additionally a full decentral P2P Email-Option via the Echo Protocol ● Store Email for Offline-Friends in the P2P Network. ● Chat and Instant Messaging is build in. ● POPTASTIC function (Chat over Email) ● Calendar widget functionality. ● Open Source. BSD License. "Cassiopeia is the tortoise of Momo, which can communicate through writing on her shell and guides into the future." - Wikipedia. Source from: https://sf.net/projects/spot-on/files/ & https://github.com/textbrowser/spot-on

NMail provides an SMTP client & server along with an IMAP4 server; all are written in C#.

Check given IP/Host presence in 106 RBLs. Now, you don\'t have to check a lot www sites, just run this script in console.

An IMAP E-mail client for X-Windows written with GTK. Supports IMAP with and without SSL.

Hedwig is an open source IMAP, SMTP, POP3 server written in Java, designed with ease of installation and configuration in mind. Hedwig enables storage of mail message headers in a relational database(MySQL or Oracle) and mail messages in a file system. Visit http://hwmail.sourceforge.net/ for more information.