Sendmail Alternatives

Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail.

sSMTP is a simple MTA to deliver mail from a computer to a mail server.

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

msmtp is an SMTP client.

OpenSMTPD is a FREE implementation of the server-side SMTP protocol as defined by RFC 5321, with...

MailerQ is a high performance Mail Transfer Agent (MTA) designed for delivering large volume email messages at very high speeds.

PowerMTA is an industrial-strength software for high-volume email delivery.

Blat is a small, efficent SMTP command line mailer for Windows.

Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.

sendEmail is a lightweight, command line SMTP email client.

CMail is a free Windows command line mailer with advanced message formatting options.

free

CheFSendeR is a simple command line tool to send emails.

open-source

Mutt is a small but very powerful text-based mail client for Unix operating systems.