Open Source C 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.

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

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.

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.

Machinet mailserver is a setup for a (small) enterprise mail server using standard GPL components

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

hotwayd/hotsmtpd are POP3/SMTP-HTTPMail gateway daemons. The HTTPMail protocol is used by the mail servers Hotmail, Lycos, Spray and MSN. The hotway suite you can receive and send mail via these services using any POP3/SMTP compliant mail reader.

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

Tools for a mail delivery service, including LMTP and POP3 servers and also getpwnam() emulation. Mail is stored in Maildir++ format (qmail plus courier extensions as soft quota and subfolders). User defined filter and virtual domains are supported.

Forpost is an embeddable, interpreted stack-based(Forth-like) language which has simple, compact and effective implementation in ANSI C. Main features: heterogeneous arrays, higher-order functions, program/data equivalence.

IVS Milter is a plugin based content filtering milter. It currently supports... Virus (ClamAV) & Spam (SpamAssassin) scanning, Content-type, Attachment type & Attachment filename matching

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.

MeTA1 is a message transfer agent that has been designed with these main topics in minds: * Security * Reliability * Efficiency * Configurability * Extendibility MeTA1 consists of five main modules of which only one runs as root: * mcp: the main control program is similar to inetd(8): it starts all other MeTA1 modules and watches over their execution. mcp runs as root in order to bind to port 25 and to change the uid of the processes it starts. * smtps: the SMTP server receives e-mails. * smtpc: the SMTP client sends e-mails. * smar: the address resolver provides lookups in various maps including DNS for mail routing. * qmgr: the queue manager controls the flow of e-mails through the SMTP servers and clients.

Qmail-patches is a set of assembled patches available for qmail. It''''''''s an easy way to improve functionality of you mail system. Patch adds: authorization support, SSL, QMAILQUEUE, filter support in qmail-smtpd, etc.

A small, fast, secure, anti-spam SMTP mail server (MTA). Delivery to mbox files and Maildirs supported. qwik-smtpd supports RBL, relay checking, raw/custom message handlers, and more. Custom authentication via checkpassword and a qmail-compatible configu

authd mail policy server; this server talks to postfix, sendmail, and anything else that wants to link to libauthd.a. The code has been stable for years, but the documentation brings us from Mature to Beta. This project has had no changes in 2+ years oth

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

ASMMS -- Anonymous SMTP Mail Message Sender ... is an simple mta, written in C, for sending mails through mail servers, which have no authentication (AUTH). It should work on nearly all POSIX systems, tested only with SunOS, Linux and HPUX.

SORBS - Spam and Open Relay Blocking System - NOT http://www.sorbs.net/ This project is to provide a SMTP proxy that automatically checks incoming SMTP connections for origination from a server with an unsecured SMTP server and/or Proxy server.

This project aims to be a personal data storage and administration system. It will be an advanced system for information and electronic mail management. The server will be accessible to any IMAPv4 compatible mail client.

This is a milter which scans emails with CRM114

The complete mail system consist of mail client written in php and mail transfer agent written in c language.

The EZ-qmail distribution is an EZ method for hobbyists / small businesses to try the qmail system for mail delivery. It provides an EZ to install, modern (patched) and working (integrated) qmail system onto which additional functionalities can be added

F1-Mailer : A simple Mailer in command line for windows users with MIME format. F1-Meiler allows people sending emails via SMTP relaying servers on the Web, with mail attachement. File attachment and email dating support. A tool to begin in Web/SMTP.