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.

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

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.

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

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

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!

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.

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

An SSL Postfix Management Interface in PHP/Ajax that handles all postfix parameters including Virtual Domains in LDAP.It handles all securities features by implementing all addons like Spamassassin,Clamav,Milter-greylist,amavis within technical skills

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.

TMDA is an open source anti-spam system and local mail delivery agent written in 100% pure Python. TMDA combines whitelists, blacklists, a challenge/response system, and special-purpose e-mail addresses called "tagged addresses" to thwart spam.

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.

Putmail is a very lightweight MTA or SMTP client that may replace the sendmail command when used by MUAs that lack SMTP support.

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

The goal of this project is to develop a very simple SMTP server that responds to SMTP requests and makes received messages available for query at a later time. All useful features for a SMTP server that can be used in an automated testing suite.

AISK is an acronym for Artificial Intelligence Spam Killer. It is a server side filter that acts as a kind of PROXY and uses SMTP to communicate with MTA. Main decision mechanism is based on artificial neural network capable of finding patterns, learning

PHP Image Script can be installed on any PHP/MySQL Environment. It is a web interface to send "anonymous" emails. It also records the emails in a database.

A proxy server for gmail, that enables you to fetch your gmails using IMAP or POP3, and send mails by SMTP via your gmail account.

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.

POSS is a suite of multi-platform PHP scripts allowing users to implement features of the SMTP protocol on their PHP enabled web-server. POSS is currently comprised of email, a fully featured, functionally compatible mail() replacement.

A collection of Webmin Modules written by Dr. Angelo 'Archie' Amoruso. Please refer to the Project Web Page (http://webmod.homelinux.org) in order to download files. Thanks.

This project builds on top of the (and adds additional) scripts included with msmtp (a command-line send only email client) in order for it to act as a queueing Mail Transport Agent (by acting as the sendmail command; it also offer an minimalist SMTP server mode) with some additional features like verify-before-send (which requires you to confirm that you really do want to send email, after a required delay (cooling off period)) for those who need to think twice about the wisdom of what they send, or who tend to notice their grammar spelling errors after the fact.

The OpenPEC project is a collaborative effort to develop an Open Source Certified E-Mail System (in italian: Posta Elettronica Certificata or PEC) as requided by the Italian law. See the DigitPA (CNIPA) site for details (http://www.cnipa.gov.it)