[EXIM] What's the problem with this header?

Hello,

does anybody know what's the problem with this header? I guess you may not
specify two From: addresses, one of them being not qualified, but I would
like to know for sure.

1999-06-25 18:08:48 10xYX1-000514-00 rejected from (mail.intramail.de) [194.25.224.251]: no valid sender in message headers: return path is <www_pro7de@???>
Recipients: jtheis@???
P Received: from [194.25.224.251] (helo=mail.intramail.de)
        by mx0.01019freenet.de with esmtp (Exim 3.02 #5)
        id 10xYX1-000514-00
        for jtheis@???; Fri, 25 Jun 1999 18:08:47 +0200
* Return-Path: <www_pro7de@???>
P Received: from mail.sevensys.de by mail.intramail.de with ESMTP for jtheis@???; Fri, 25 Jun 1999 18:08:58 +0200
P Received: from wilna.pro-sieben.de (wilna [193.158.32.86])
        by mail.sevensys.de (8.8.8/8.8.8) with SMTP id SAA09181
        for <jtheis@???>; Fri, 25 Jun 1999 18:08:45 +0200 (MET DST)
P Received: by wilna.pro-sieben.de (SMI-8.6/SMI-SVR4)
        id SAA00330; Fri, 25 Jun 1999 18:08:41 +0200
  Date: Fri, 25 Jun 1999 18:08:41 +0200
I Message-Id: <199906251608.SAA00330@???>
F From: ProSieben,
      Online@???
  Subject: Eine ProSieben Online Postkarte
  Apparently-To: jtheis@???
B Bcc:

Michael

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