I’m in the process of moving back to a postfix/dovecot setup for hosting my own mail and I wanted a way to remove the more sensitive email headers that are normally generated when I send mail. My goal is to hide the originating IP address of my mail as well as my mail client type and version. To get started, make a small file with regular expressions in /etc/postfix/header_checks: /^Received:.*with ESMTPSA/ IGNORE /^X-Originating-IP:/ IGNORE /^X-Mailer:/ IGNORE /^Mime-Version:/ IGNORE The “ESMTPSA” match works for me because I only send email via port 465.