blat - Blat is a small, efficent SMTP command line mailer for Windows.
CMail - CMail is a free Windows command line mailer with advanced message formatting options.
sendEmail - sendEmail is a lightweight, command line SMTP email client.
Mailer - Free utility to send emails from the command line. No Installation. All contained in one file.
Sendmail - Sendmail is a general purpose internetwork email routing facility that supports many kinds of...
msmtp - msmtp is an SMTP client.