Procmail and Carbon Copy Mailing

I am a complete amateur at using procmail and unix so please be patient.

I have set up procmail on our virtual server and am using it to forward
mail to other email addresses.  This is working fine, however, if I send
mail to say 
user1(_at_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_) and 
CC: user2(_at_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_)(_dot_) 
the mail to the second
user must get stripped away or something.  So is there some easy way to
allow the message to continue on without creating a large amount of
surplus mail in some bucket at the end of the list.

If I just deleted mail that went through the whole list how can I trap
mail that was not addressed properly or had problems etc.

If this is unclear or needs elaborating please write.

Thanks,

Hugh.