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.
- - Postfix is the most popular Mac & Linux alternative to esmtp.
- - Postfix is the most popular Open Source & free alternative to esmtp.
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.
sSMTP is a simple MTA to deliver mail from a computer to a mail server. sSMTP is simple and lightweight, there are no daemons or anything hogging up CPU; Just sSMTP. Unlike Exim4, sSMTP does not receive mail, expand aliases, or manage a queue.Discontinued
The last update was in 2013.
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 feature rich. It was designed to be used in bash scripts, batch files, Perl programs and web sites, but is quite...
- - sendEmail is the most popular Windows alternative to esmtp.
NikaMail is a portable, extendable, zero-config email server. It is designed to perform automation tasks, provide access to mailboxes (port 110), serve as a mail transfer agent (port 587) and mail exchange service (port 25). NikaMail supports TLS.
SMTPc is simple SMTP client for easy mail sending using CLI. It's dedicated for developers, however it's easy to use and every CLI user will be satisfied using this.