I'm wondering if anyone can explain what a user could be doing to get
this result in the mime file trying to leave our gwia. It ends up in
the defer folder and cannot get delivered obviously.

<destination MX>
EHLO <our MX>
MAIL FROM:<mail@ourdomain>
*U1* RCPT TO:<address1@destemail address2@destemail address3@destemail>
Received: from campgwia-MTA by <our MX>
with Novell_GroupWise; Tue, 15 Dec 2015 13:37:50 -0700
Message-Id: <messageID@ourMX>
X-Mailer: Novell GroupWise Internet Agent 14.0.1
Date: Tue, 15 Dec 2015 13:37:41 -0700
From: "User name" <user email address>
To: <address1@destemail address2@destemail address3@destemail>
Subject: <SUBJECT>

The part I'm concerned with is where the To: & RCTP TO: have multiple
email addresses separated by spaces.