[Assp-user] mail queue full of "Delivery Status Notification (Failure)"

[Graziano <dre...@li...>]

Hello

on some server running assp mail MTA queue get full of messages like these

=========================================================================
186P Received: from [127.0.0.1] (helo=orngca-mx-13.mgw.rr.com)
    by host.bus-server.com with esmtp (Exim 4.66)
    id 1IVubn-00016e-Rw
    for t-...@my...; Thu, 13 Sep 2007 15:44:16 -0400
130P Received: from orngca-mx-13.mgw.rr.com ([66.75.160.147] 
helo=orngca-mx-13.mgw.rr.com)
    by ASSP.nospam; 13 Sep 2007 15:44:15 -0400
082P Received: from localhost by orngca-mx-13.mgw.rr.com;
  13 Sep 2007 15:44:56 -0400
053I Message-Id: <68dnmj$1u...@or...>
033  Date: 13 Sep 2007 15:44:56 -0400
026T To: t-...@my...
069F From: "Mail Delivery System" <MAI...@or...>
048  Subject: Delivery Status Notification (Failure)
018  MIME-Version: 1.0
104  Content-Type: multipart/report; report-type=delivery-status; 
boundary="1z3KYC.4EWcIe0HS.1qluq4.2NTkpiK"
066  X-Assp-Delay: not delayed (spamlover); 13 Sep 2007 15:44:15 -0400
126  X-Assp-Received-SPF: pass (ASSP.nospam: local policy) 
client-ip=66.75.160.147;
    envelope-from=; helo=orngca-mx-13.mgw.rr.com;
028  X-Assp-Received-DNSBL: pass
027  X-Assp-Score: 10 (BombRaw)
028  X-Assp-Received-URIBL: pass
028  X-Assp-Score: 25 (Bayesian)
027  X-Assp-Spam-Level: *******
023  X-Assp-Envelope-From:
043  X-Assp-Intended-For: t-...@my...

1IVubn-00016e-Rw-D
--1z3KYC.4EWcIe0HS.1qluq4.2NTkpiK
content-type: text/plain

The following message to <91_...@ha...> was undeliverable.
The reason for the problem:
5.1.0 - Unknown address error 550-'5.1.1 unknown or illegal alias: 
91_...@ha...'
...............
...............
=========================================================================

I understand that when the spammer send an email to an invalid user , 
assp returns an email to the sender .
And if the sender does not exist I receive the "Delivery Status 
Notification (Failure)" email .
How to reduce these ? assp can help on this ?

Thanks
Graziano