swaks – command line SMTP testing tool
swaks is a command line SMTP testing tool available at http://www.jetmore.org/john/code/swaks/ On Debian/Ubuntu, you can install it with if you
Configure postfix to relay mails using SendGrid
To use postfix to send email using sendgrid, you first you need to install postfix on your server. Edit main.cf
Mail Server These software once installed will provide complete mail server including web mail. iRedMail Mail-in-a-Box https://mailcow.email https://kopano.com https://modoboa.org –