User caused duplicate emails

I use RT for my team and get requests from Exchange. The problem is that
after I set the following under RT_Config.pm:

Set($ParseNewMessageForTicketCcs , 1);

Replies sent from RT are showing the people cc’d and therefore the users are
replying to all instead of just RT, thus causing duplicate emails. One from
RT and the other from Exchange.

Is there any way of not showing the people cc’d from the first request on
correspondences?

This electronic mail message contains information that (a) is or may be
CONFIDENTIAL, PROPRIETARY IN NATURE, OR OTHERWISE PROTECTED BY LAW FROM
DISCLOSURE, and (b) is intended only for the use of the addressee(s)
named herein. If you are not an intended recipient, please contact the
sender immediately and take the steps necessary to delete the message
completely from your computer system.

Not Intended as a Substitute for a Writing: Notwithstanding the Uniform
Electronic Transaction Act or any other law of similar effect, absent
an express statement to the contrary, this e-mail message, its
contents, and any attachments hereto are not intended to represent an
offer or acceptance to enter into a contract and are not otherwise
intended to bind this sender, barnesandnoble.com llc,
barnesandnoble.com inc. or any other person or entity.