[CentOS] OT - has my email domain been hijacked?

Returned mail: User unknown
Hi List;

I keep getting emails similar to the text below. I/We own the domain 
dataintellect.com and we have email addresses setup however I always see a 
bogus dataintellect.com email address as the sender.

-or is this simply a random spam email?

Thanks in advance for any advice...


=========================================


From: 
Mail Delivery Subsystem <MAILER-DAEMON at aol.com>
  To: 
carina_x at dataintellect.com
  Date: 
Today 13:31:26
   
  Spam Status: Spamassassin 0% probability of being spam.

Full report:
No, score=0.0 required=5.0 tests=AWL,BAYES_50 autolearn=no  version=3.0.4  
The original message was received at Wed, 14 Sep 2005 15:31:23 -0400 (EDT)
from client-201.230.112.161.speedy.net.pe [201.230.112.161]


*** ATTENTION ***

Your e-mail is being returned to you because there was a problem with its
delivery.  The address which was undeliverable is listed in the section
labeled: "----- The following addresses had permanent fatal errors -----".

The reason your mail is being returned to you is listed in the section
labeled: "----- Transcript of Session Follows -----".

The line beginning with "<<<" describes the specific reason your e-mail could
not be delivered.  The next line contains a second error message which is a
general translation for other e-mail servers.

Please direct further questions regarding this message to your e-mail
administrator.

--AOL Postmaster



   ----- The following addresses had permanent fatal errors -----
<acardi at cs.com>
<adorablealicia at cs.com>
<aclaudet at cs.com>
<acarter5 at cs.com>
<acrader at cs.com>

   ----- Transcript of session follows -----
... while talking to air-yg01.mail.aol.com.:
>>> RCPT To:<acrader at cs.com>
<<< 550 MAILBOX NOT FOUND
550 <acrader at cs.com>... User unknown
>>> RCPT To:<acarter5 at cs.com>
<<< 550 MAILBOX NOT FOUND
550 <acarter5 at cs.com>... User unknown
>>> RCPT To:<aclaudet at cs.com>
<<< 550 MAILBOX NOT FOUND
550 <aclaudet at cs.com>... User unknown
>>> RCPT To:<adorablealicia at cs.com>
<<< 550 MAILBOX NOT FOUND
550 <adorablealicia at cs.com>... User unknown
>>> RCPT To:<acardi at cs.com>
<<< 550 MAILBOX NOT FOUND
550 <acardi at cs.com>... User unknown
unnamed

Received: from  client-201.230.112.161.speedy.net.pe 
(client-201.230.112.161.speedy.net.pe [201.230.112.161]) by 
rly-yg02.mx.aol.com (v107.10) with ESMTP id MAILRELAYINYG23-26f43287a8232f; 
Wed, 14 Sep 2005 15:31:21 -0400
Received: from mail.strawberrysampler.com ([64.118.71.80]) by 201.230.112.161 
with ESMTP id 4868741;
         Wed, 14 Sep 2005 19:21:59 -0100
Received: (qmail 73986 invoked by uid 5164); Date: Wed, 14 Sep 2005 19:21:59 
-0100
Date: Wed, 14 Sep 2005 19:21:59 -0100
Message-ID: <20050914.68664.carina_x at dataintellect.com>
From: "Men of Focus" <carina_x at dataintellect.com>
Sender: carina_x at dataintellect.com
To: acardi at cs.com, adorablealicia at cs.com, aclaudet at cs.com, acarter5 at cs.com,
        acrader at cs.com
X-Responder-ID: 14
Subject: Living without concerns!
Content-Type: text/html; charset="UTF-8"
X-AOL-IP: 201.230.112.161
X-AOL-SCOLL-SCORE: 1:2:306687321:10737418
X-AOL-SCOLL-URL_COUNT: 3