Reject / Discard / Redirect emails based on header checks : vi /etc/postfix/main.cf header_checks = regexp:/etc/postfix/header_checks vi /etc/postfix/header_checks /^From: "Mechanic/ REJECT /^To: someone@example.com/ REDIRECT someone@example2.com /^To [someone@example2.com/%5ETo]: [bademail@example.com/ REJECT /^Subject](mailto:bademail@example.