Stop reply email code for Exchange

I have been asked to create an email address to be used for mailing out information to people who have requested it; But it needs to appear that it has either been sent from an account that is not on our domain (fake or spoofed) or hides it’s self so that it can not be replied to.
There are many valid reasons for this.
One is many people expect a answer if they reply to an email even if Do Not Reply to this email! is in the subject line.
It would be even better if the email address can be replaced with a code that tells the recipiants mail client/server not to send any kind of reply ( bounce out of office etc)
So when they recieve the email they have to read it for the correct address to reply to.