Correo Electrónico - mensaje "Firewall Denial of Service Log"

No paro de recibir correos electronicos enviados desde mi propia cuenta con el asunto "Firewall Denial of Service Log" pero nada mas.
¿Alguien sabe por que?

Adjunto el log de uno de ellos:

X-MDAV-Processed: alpusa.homeip.net, Sat, 02 Apr 2011 18:52:24 +0200
X-Spam-Processed: alpusa.homeip.net, Sat, 02 Apr 2011 18:52:13 +0200
Return-path: <[email protected]>
X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10)
X-Spam-Level:
X-Spam-Status: No, score=-100.0 required=5.0 tests=USER_IN_WHITELIST
shortcircuit=ham autolearn=disabled version=3.2.5
X-Spam-Report:
* -100 USER_IN_WHITELIST From: address is in the whitelist
Received: from mail.requeni.com ([84.246.209.31])
by alpusa.homeip.net (alpusa.homeip.net)
(MDaemon PRO v11.0.0)
with MultiPOP id md50000005153.msg
for <[email protected]>; Sat, 02 Apr 2011 18:52:13 +0200
X-MDMultiPOP: [email protected]@mail.requeni.com
X-Rcpt-To: [email protected]
X-MDRcpt-To: [email protected]
X-MDRemoteIP: 84.246.209.31
X-Return-Path: [email protected]
X-Envelope-From: [email protected]
X-MDaemon-Deliver-To: [email protected]
Received: from mailhost.requeni.com ([10.38.74.63])
by gamma.infortelecom.net
with hMailServer ; Sat, 2 Apr 2011 18:50:21 +0200
Message-ID: <[email protected]>
From: < [email protected]>
To: < [email protected]>
Subject: Firewall Denial of Service Log
Illegal TCP header DETECTED on Sat Apr 02 17:50:05 2011
targeting 172.30.0.2,0, sent from 83.50.120.244,0
X-Antivirus: avast! (VPS 110402-1, 02/04/2011), Inbound message
X-Antivirus-Status: Clean

Gracias de antemano para quien pueda ayudar.

Saludos