Open Source Linux Mail Transfer Agents

E-MailRelay is a simple SMTP proxy and relay MTA, written in C++, for Linux and Windows. As a proxy all messages can be passed through a user-defined program, such as a spam-filter, which can drop, readdress, or edit messages as they pass through.

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.

mailsend is a simple command line program to send mail via SMTP protocol. It can send a piece of alert mail from a program in a networked Windows machine. It's feature-filled, cross-platform, free and open source, and does not use any config file.

MailArchiva is a powerful, full featured email archiving (email archiver) and compliance solution for mail systems such as Microsoft Exchange. It stores all incoming, outgoing and internal emails for long term storage. A web based user interface is avail

Provide an Open Source Java Email Server that supports POP3/SMTP.

ESMTP MTA is a user configurable relay-only MTA with a sendmail-compatible syntax, based on libESMTP and supporting the AUTH (including the CRAM-MD5 and NTLM SASL mechanisms) and the StartTLS SMTP extensions.

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!

A qmail patch which provides plug-in support for it`s SMTP daemon.

Visual Synapse are component wrappers around the Synapse tcp/ip libraries. It wraps a few common internet protocols, like HTTP, UDP, DNS, ICMP, TCP and SMTP to multi-threaded components that can be used with Delphi, Kylix, Freepascal and C++ Builder.

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

GreenMail is an intuitive and easy-to-use test suite of email servers for testing purposes. Supports SMTP, POP3, IMAP with SSL socket support, and configurable user accounts and credentials. All in 100% Java. WE'VE MOVED TO GIT HUB: https://github.com/greenmail-mail-test/greenmail

Python API for Sendmail Milters. Related modules provide features such as content filtering, SPF, and reputation tracking. Changes are posted first to https://github.com/sdgathman/pymilter and related repos.

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

JMultiSend is a simple and fast solution to send mass emails (Bulk E-mail); it only needs to load the list of addresses, the message (HTML or TXT), the data and then send. It is possible also to manage mailing lists subscribtions simply by emails, to send personalized messages with the user name and to schedule delays up to 24h (86400 secs); all this also from command-line. Since it is developed in Java it is a cross-platform application and does not need installation but needs only the Java Virtual Machine (version 6 or higher) that, in the case, is very easy to download and install.

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

Mailfilter to secure maildrops while fetch mails from a remote mail server and prevent mailloops, unwanted resend to external receipients and/or virus and spam.

Foedus Mail is a mail server written in Java. The goal is to produce stable IMAP, SMTP, and POP3 support and then to build upon and refine it.

Jamm (Java Mail Manager) is a web application to manage virtual email account information stored in an LDAP directory. It is meant as an administration tool for sites using mail servers, such as Postfix and Courier-IMAP.

Pure Perl implementation of the Milter protocol used by Sendmail, including drop-in replacement for the Sendmail::Milter interface.

PyWebMail is a Python library and POP3 gateway that enable working with WebMail servers like with POP3 or IMAP mail server. Currently Mail.Com, Yahoo! Mail, Gmail, Netscape.Net, HotMail and some minor servers support is finished.

This java program allows you to make backups of your emails from one server to an other by copying emails over IMAP. It can also be used to switch emails you have from your old provider to your new one.

Amail is a mail deamon with web interface. Writen in PHP and C++.

GITST Email Sender allows you to send multiple emails from multiple email accounts adding limits on each email account For example, you want to send 500 from gmail then switch to yandex and send 300 from yandex and so on that is all what it does sends unlimited emails from multiple different email accounts it is basics of anti-spam penetration system

J-MAIL : an Open Source Java technology based email user agent using the JavaMail API