I am using mydomain.com as the central server and myrelay.com as one of my SMTP relays.I currently have the following set to convert the headers./etc/postfix/header_checks/^Received:/ IGNORE/Message-Id:\s+<(.*?)@www.mydomain.com>/   REPLACE Message-Id: <$1@www.myrelay.com>/etc/postfix/main.cfheader_checks = pcre:/etc/postfix/header_checksHow would I go about checking on the relay for anything else to do with mydomain.comsuch as the subject or email message content (which may contain hyperlinks linking to mydomain.com)and then converting it to myrelay.com. I want there to be zero possible trace of mydomain.com anywhere in the full email headers.
Postfix relay - Remove all traces of main node domain
postfix