How to add header subject in postfix

July 2, 2019, admin, 0

If you want to add subject in the postfix log files, add the following in main.cf file at the bottom.

vi /etc/postfix/main.cf

header_checks = regexp:/etc/postfix/header_checks
smtp_header_checks = regexp:/etc/postfix/header_checks

And add the lines below in /etc/postfix/header_checks files, create the file if it’s not already there.

/^subject:/ WARN
/^X-PHP-Originating-Script:/ WARN

Now restart postfix server using command:

service postfix restart

Now the subject and the php script / file that is sending emails will be logged to maillog.

You can also add to: and from: the same way.

Add the following to the header_checks file.

/^to:/ WARN
/^from:/ WARN
/^To:/ WARN
/^From:/ WARN

This is very useful to find the php scripts that are used to send emails from your server or in time of spamming, to find the culprit.