Open Source Linux Mail Transfer Agents

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.

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.

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

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.

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

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

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

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

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!

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.

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

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

Add-ons/modifications of sendmail m4 configuration files and helper programs/utilities. 2013-01-04: The project is frozen. It may be unfrozen after registration of users, testers, developers.

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.

NetPop -- a Netscape / AOL Email Popper written in Java, much like YPOPs! for Yahoo mail and Mr Postman for Hotmail, that allows anyone to use a POP3 email client (Thunderbird, Eutora, Outlook, etc) with Netscape and AOL webmail.

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)

Smtp Relay Checker is a network open mail relay checker. It is muti-threaded so it can be used to scan vast networks quickly, it is fully configurable so it can be adjusted to suit any need, and the scan results can be displayed in HTML. It is intended f

smtptrapd is a multi-threaded daemon written in C that provides a RFC 2821 compliant SMTP service that always returns a 4xx soft error to the RCPT TO verb. It can be deployed as a secondary MX to reduce the amount of inbound spam.

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

This anonymous emailer script written in PHP is a free, opensource project designed to send EMails from anyone to anyone, with additional details such as Reply-To ,an anti-spam CAPTCHA and a WYSIWYG.

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.

Moved to GitHub → https://github.com/yoctobyte/visualsynapse --- 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.

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.

Policy-daemon for the postfix MTA in perl. Scores RBLs, RHSBLs, HELO, Client IP and MAIL FROM argument and sums up a score on which you can reject the mail before DATA will be received. Results are cached. I.e: a weighted SMTP filter before DATA (queue).

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