Buenas, ¿cómo van?

He leído sendos artículos acerca de como usar el parámetro "header_checks=" o "postfix_header_checks=", para tratar de ocultar la información de las cabeceras de mis correos, pero no he tenido ningún resultado:

Code:
Delivered-To: a.calderon@...
Received: by 10.52.175.135 with SMTP id ca7csp39751vdc;
        Mon, 6 Aug 2012 22:07:50 -0700 (PDT)
Received: by 10.236.178.38 with SMTP id e26mr12374534yhm.12.1344316070485;
        Mon, 06 Aug 2012 22:07:50 -0700 (PDT)
Return-Path: <admin@....net>
Received: from z.....net ([190.29.24.XX])
        by mx.google.com with ESMTP id e22si20666236yhh.67.2012.08.06.22.07.50;
        Mon, 06 Aug 2012 22:07:50 -0700 (PDT)
Received-SPF: neutral (google.com: 190.29.24.XX is neither permitted nor denied by best guess record for domain of admin@...net) client-ip=190.29.24.XX;
Authentication-Results: mx.google.com; spf=neutral (google.com: 190.29.24.XX is neither permitted nor denied by best guess record for domain of admin@i....net) smtp.mail=admin@...net
Received: from localhost (xxxxx [127.0.0.1])
	by z.....net (Postfix) with ESMTP id 5EE15A1CBE
	for <a.calderon@...net>; Tue,  7 Aug 2012 00:10:47 -0500 (COT)
X-Virus-Scanned: amavisd-new at infern0.net
Received: from z.....net ([127.0.0.1])
	by localhost (z.....net [127.0.0.1]) (amavisd-new, port 10024)
	with ESMTP id vGh2Juk6q4Zp for <a.calderon@.net>;
	Tue,  7 Aug 2012 00:10:47 -0500 (COT)
Received: from z.....net (z.....net [192.168.16.XX])
	by z.infern0.net (Postfix) with ESMTP id 349B0A1CB3
	for <a.calderon@....net>; Tue,  7 Aug 2012 00:10:47 -0500 (COT)
Date: Tue, 7 Aug 2012 00:10:47 -0500 (COT)
From: admin@i....net
To: a.calderon@....net
Message-ID: <1386219376.3.1344316247101.JavaMail.root@....net>
Subject: Prueba 550559
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit

Con base en lo anterior, se puede observar la cantidad de información contenida en la cabecera del mensaje, información que eventualmente puede servir para comprometer el sistema.


Contenido de postfix_header_checks.in:

Code:
/^Received: from 127.0.0.1/ IGNORE
/^User-Agent:/  IGNORE
/^X-Mailer:/    IGNORE
/^X-Originating-IP:/    IGNORE
%%uncomment VAR:zimbraMtaBlockedExtension%%/filename=\"?(.*)\.(%%list VAR:zimbraMtaBlockedExtension |%%)\"?$/
%%uncomment VAR:zimbraMtaBlockedExtension%% REJECT For security reasons we reject attachments of this type
%%uncomment VAR:zimbraMtaBlockedExtension%%/^\s*Content-(Disposition|Type).*name\s*=\s*"?(.+\.(%%list VAR:zimbraMtaBlockedExtension |%%))"?\s*$/
%%uncomment VAR:zimbraMtaBlockedExtension%% REJECT Attachment type not allowed. File "$2" has the unacceptable extension "$3"
Versión de zimbra:

zmcontrol -v

Code:
Release 7.2.0_GA_2669.RHEL6_64_20120410002025 CentOS6_64 FOSS edition.

Muchas gracias por su ayuda,

A.