can smail change the Envelope?

[Thomas Adams <tadams@pobox.com>]

I usually write email on the Debian box here, for which I installed UUCP and 
SMail, which works fine. I can change the From: line to whatever I like and my 
provider still accepts and delivers the emails. So far, so good.

But there is a Mac here which communicates with my Linux box via Ethernet and 
which I would also like to send mail from. I installed Internet Config and 
MacSOUP and started reading mail. Worked fine. Then I send some email which 
returned with an error message from my provider's MTA. It told me 
the return-path of my message was wrong.

I assume what it means is the first line in an email's header which looks like:
>From cat.ping.de!tom
.
.
From: Thomas Adams <tadams@pobox.com>
.
.

If my assumption is correct then MacSOUP generates a wrong header because 
the first line looks like:
>From pobox.com!tadams

Now I wonder if I can configure SMail in such a way that it rewrites the first 
>From line (aka Envelope?) to a format my provider likes?

Below is an example error message:

>From MAILER-DAEMON Mon Sep  7 08:51:14 1998
Return-Path: <real-tom>
Received: by cat.ping.de
	via rmail from stdin
	id <m0zFv8q-0005MNC@cat.ping.de> (Debian Smail3.2.0.101)
	for tom@cat.ping.de; Mon, 7 Sep 1998 08:51:12 +0200 (CEST) 
Received: (qmail 12284 invoked by uid 10); 6 Sep 1998 22:54:28 -0000
Date: 6 Sep 1998 22:54:28 -0000
Message-ID: <19980906225428.12283.qmail@lilly.ping.de>
To: tom@cat.ping.de
From: MAILER-DAEMON@lilly.ping.de
Subject: Mail failed - invalid return-path
Status: RO
Content-Length: 1191
Lines: 31

Hi. This is the rmail program at lilly.ping.de.
I am afraid I can only accept messages that have a valid return-path
(or From_ line) pointing to an address in the .ping.de domain.  This
is a permanent error; I've given up. Sorry it didn't work out.

--- Below this line is a copy of the message.

>From pobox.com!tadams Sun Sep  6 21:50:56 1998 remote from cat
Received: from [192.168.1.2] (really [192.168.1.2]) by cat.ping.de
	via in.smtpd with smtp
	id <m0zFkps-0005MGC@cat.ping.de> (Debian Smail3.2.0.101)
	for <xxx@xxxx.xxx>; Sun, 6 Sep 1998 21:50:56 +0200 (CEST) 
To: xxx@xxxx.xxx (xxxxxx xxxxxx)
Subject: xxxxx xxxxxxx  xxxxxxx
From: tadams@pobox.com (Thomas Adams)
Date: Sun, 6 Sep 1998 21:50:53 +0200
Message-ID: <1deyext.1a9gmf117g29fbM@[192.168.1.2]>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
Organization: none
X-Mailer: MacSOUP D-2.3.1 (unregistered)