List of Email Addresses at Footer of Email

At the footer of an email message (Exchange 2010) states "No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3462 / Virus Database: 3722/7187 - Release Date: 03/12/14
Internal Virus Database is out of date", followed by a list of email addresses.

Any idea?

Thanks!