Postfix

Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail. It attempts to be fast, easy to administer, and secure. The software is also known by its former names VMailer and IBM Secure Mailer.

Free Open Source Mac OS X Linux

Exim

Exim is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet.

Free Open Source Mac OS X Windows Linux

Courier-MTA

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.

Free Open Source Mac OS X Linux BSD Self-Hosted

blat

Blat is a small, efficent SMTP command line mailer for Windows. It is the SMTP *sending* part of an eMail User Agent (MUA) or eMail client. As such, Blat sends eMail via...

Free Open Source Windows

Dragonfly Mail Agent

a small mail transport agent (mta), designed for home and office use. part of http://alternativein .

Free Open Source Linux BSD

Sendmail

Sendmail is a general purpose internetwork email routing facility that supports many kinds of transfer and delivery methods, including the Simple Mail Transfer Protocol (SMTP) used for email transport over the Internet.

Free Open Source Mac OS X Linux

OpenSMTPD

OpenSMTPD is a FREE implementation of the server-side SMTP protocol as defined by RFC 5321, with some additional standard extensions. It allows ordinary machines to...

Free Open Source Linux BSD Self-Hosted

Hectane

An SMTP client that is extremely easy to configure and use, providing a simple HTTP API that is used for sending emails.

Free Windows Linux

Microsoft SMTP Server

Configure SMTP e-mail in IIS when you want to deliver e-mail messages from your site. Mail can be delivered immediately or it can be delivered to a file location on disk...

Commercial Windows

msmtp

In the default mode, it transmits a mail to an SMTP server (for example at a free mail provider) which takes care of further delivery. To use this program with your...

Free Open Source Linux Xfce

sendEmail

sendEmail is a lightweight, command line SMTP email client. If you have the need to send email from a command line, this free program is perfect: simple to use and...

Free Open Source Mac OS X Windows Linux

Mailer

Free utility to send emails from the command line. No Installation. All contained in one file.

Free Windows Linux

CMail

CMail is a command line mailer, originally developed for testing mail server software, but is simple enough to use interactively. CMail supports IPv6, TLS/SSL...

Free Windows

BulkMTA

BulkMTA is Commercial Mail Server Similar to PowerMTA. IP Rotation, DKIM, Sender / Receiver Rate limiting

Commercial Mac OS X Windows Linux

esmtp

esmtp is a user configurable relay-only Mail Transfer Agent (MTA) with a sendmail compatible syntax. It's based on libESMTP supporting the AUTH (including the...

Free Open Source Linux BSD