postfix – Remove/Hide Client Sender IP from Postfix

I'm trying to hide the client IP from emails sent from postfix.

here is an example of what I mean:

Received: from mail.[removed].com (adsl-75-37-61-254.dsl.frs2ca.sbcglobal.net [75.37.61.254])
    (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
    (No client certificate requested)
    by mail.[removed].com (Postfix) with ESMTP id D50C7BF185DD
    for <[removed]@gmail.com>; Thu,  2 Aug 2012 16:14:21 +0900 (JST)
Date: Thu, 02 Aug 2012 07:14:08 +0000

Notice this line (adsl-75-37-61-254.dsl.frs2ca.sbcglobal.net [75.37.61.254])

I want to remove that line from the email.

I've tried doing this:

/etc/postfix/main.cf :

smtp_header_checks = regexp:/etc/postfix/smtp_header_checks

smtp_header_checks :

/^((.*) [(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])])/    IGNORE

But my IP address is still inside of the received part of the email. If I send email off the smtp server locally the IP address becomes localhost.localdomain [127.0.0.1]

How can I remove client IPs from the header?