RT's Subject Line

I am writing this is regards to how the Subject line of an email response is

The problem has come to light recently since the head office has put spam
filters on all our email traffic looking for an email address in the subject
line of email’s that are being sent through the exchange servers.

During ticket creation from an end user, the ticket/queue owner is sent an
email stating that so and so has sent in a request and a ticket was created.
At the end of the subject line the end user’s email address is added to the
subject line of the email that is sent out from RT. Also when the requestor
reply’s to a ticket his/her email address is tacked onto the response that
is sent out to the ticket owner.

i.e. Subject: [Helpdesk #333](queue name)Transaction(requestor email

Is there somewhere in RT that I can hack it to remove the requestor’s email
address from the subject line so that the spam filters don’t pick the
message up. This problem needs to be overcome as end user’s are sending in
responses to tickets that are created and the IT group is not receiving them
as the response’s are being sent to the bit bucket.

We are presently using RT 1.0.7 on a Redhat 7.2 setup, using Postfix for the
mailer through which sends th e outgoing mail to an exchange server mailbox.
We are looking into RT3.0.0, but not quite ready to jump on the band wagon.