Date: 2019feb8 Product: Postfix Q. Postfix: Hide version and name A. You don't have to show everyone who connects to your mail server exactly what you're running. In file /etc/postfix/main.cf

# Comment out lines like this # smtpd_banner = $myhostname ESMTP $mail_name # smtpd_banner = $myhostname ESMTP $mail_name ($mail_version) # Leave this smtpd_banner = $myhostname ESMTP

$mail_name is 'Postfix' $mail_version is your version of Postfix So why show either?