[fetchmail]Fetchmail/postfix in multidrop mode?

[Jef Driesen]

I have an emailaddress (username@isp.tld) from my ISP (telenet.be) and
another emailaddress (user@mydomain.tld) from my webhosting provider
(hostingweb.be) that is forwarded to the first emailaddress. Is there
some way to separate them again with my fetchmail/postfix setup? Or by
using some other program(s)?

The headers for an example message, send from username@isp.tld to
user@mydomain.tld (using BCC field) do look like:

Return-Path: <username@isp.tld>
Delivered-To: username@isp.tld
Received: (qmail 27365 invoked from network); 10 Mar 2006 17:17:24 -0000
Received: from herakles.telenet-ops.be ([195.130.136.20])
           (envelope-sender <username@isp.tld>)
           by menthe.telenet-ops.be (qmail-ldap-1.03) with SMTP
           for <username@isp.tld>; 10 Mar 2006 17:17:24 -0000
Received: from ladon.telenet-ops.be (ladon.telenet-ops.be [195.130.132.50])
     by herakles.telenet-ops.be (8.12.8/8.12.8) with ESMTP id k2AHHOiQ001760
     for <username@isp.tld>; Fri, 10 Mar 2006 18:17:24 +0100
Received: from nocmmga1.telenet-ops.be (unknown [195.130.132.35])
     by ladon.telenet-ops.be (Postfix) with ESMTP id D273E312773
     for <username@isp.tld>; Fri, 10 Mar 2006 18:17:24 +0100 (CET)
Received: from unknown (HELO s01.hostingweb.be) ([193.43.88.21])
   by nocmmga1.telenet-ops.be with ESMTP; 10 Mar 2006 18:17:15 +0100
Received: from hoboe1bl1.telenet-ops.be ([195.130.137.72])
     by s01.hostingweb.be with esmtp (Exim 4.50)
     id 1FHlF0-0000A3-ID
     for user@mydomain.tld; Fri, 10 Mar 2006 18:17:26 +0100
Received: from localhost (localhost.localdomain [127.0.0.1])
     by hoboe1bl1.telenet-ops.be (Postfix) with SMTP
     id C8CBAD443D; Fri, 10 Mar 2006 18:17:22 +0100 (CET)
Received: from [xx.xx.xx.xx] (xx.access.telenet.be [xx.xx.xx.xx])
     by hoboe1bl1.telenet-ops.be (Postfix) with ESMTP
     id B20E6D42B7; Fri, 10 Mar 2006 18:17:22 +0100 (CET)
Message-ID: <4411B4A2.6050307@telenet.be>
Date: Fri, 10 Mar 2006 18:17:22 +0100
From: Jef Driesen <username@isp.tld>
MIME-Version: 1.0
To: undisclosed-recipients: ;
Subject: test
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit