[sniffer] Help

[Filippo Palmili]

Hello Pete,

my Ipswitch IMail Server is under attack since yesterday. It relays
emails coming from an external host.
The sender of these mails is a random name @ the ip address of my mail
server (for example [EMAIL PROTECTED]) and is automatically
whitelisted by the declude server.
Do you know anything about these attacks? Is there a way to stop it?
Until now I banned the generating ip address and manually delete the
queue, but the generating address changes.

Ad example of mail:

Received: from ameillpu-7jat6i [200.127.81.225] by odino.logos.it with ESMTP
  (SMTPD32-8.05) id AB60DC5500D0; Thu, 27 Jul 2006 17:27:28 +0200
From: "bjsytb" <[EMAIL PROTECTED]>
Subject: =?GB2312?B?usN+zsR+ubJ+yc0=?=
To: [EMAIL PROTECTED]
Content-Type: TEXT/HTML
Date: Thu, 27 Jul 2006 23:27:23 +0800
X-Mailer: AOL 7.0 for Windows US sub 118
Message-Id: <[EMAIL PROTECTED]>
X-Declude-Sender: [EMAIL PROTECTED] [200.127.81.225]
X-Declude-Spoolname: DDB60DC5500D0D472.SMD
X-Declude-Scan: Score [0] at 17:28:19 on 27 Jul 2006
X-Declude-Tests: Whitelisted

Please let me know.
Filippo

Logos S.p.A.