We are using the network edition of Zimbra and I need some help!

We have a user whose email is being marked as spam and I am not sure why. The message header looks like the following:

Received: from localhost (localhost.localdomain [])
by ourdomain.com (Postfix) with ESMTP id 4321C760360;
Fri, 7 Dec 2007 08:15:32 -0500 (EST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: YES
X-Spam-Score: 10.028
X-Spam-Level: **********
X-Spam-Status: Yes, score=10.028 tagged_above=-10 required=6.6
tests=[AWL=-1.270, BAYES_50=0.001, DNS_FROM_RFC_BOGUSMX=1.482,
Received: from ourdomain.com ([])
by localhost (ourdomain.com []) (amavisd-new, port 10024)
with ESMTP id kn7MfuRXbYgm; Fri, 7 Dec 2007 08:15:25 -0500 (EST)
Received: from 245.sub-75-198-83.myvzw.com (245.sub-75-198-83.myvzw.com [])
by ourdomain.com (Postfix) with ESMTP id 2B03E76035D;
Fri, 7 Dec 2007 08:15:22 -0500 (EST)
Message-Id: <F12286E7-4414-4C23-AAA3-F02FF429977D@ourdomain.com>
From: Wayne
To: Brenda
In-Reply-To: <215013471.164781197032804100.JavaMail.root@ourdom ain.com>
Content-Type: multipart/alternative; boundary=Apple-Mail-8--317212103
Mime-Version: 1.0 (Apple Message framework v912)
Subject: Re:
Date: Fri, 7 Dec 2007 08:15:19 -0500
References: <215013471.164781197032804100.JavaMail.root@ourdom ain.com>
X-Mailer: Apple Mail (2.912)

This appears to only happen when he sends email when his in not in the office, but using a ISP.

What exactly does: DNS_FROM_RFC_BOGUSMX=1.482 mean?