option to add extra users in To field.

We discovered that al lot of customers don’t pay attention in receiving mail when they are in de CC field. Some of them have even rules for that to give it a low priority . This means that if there are tickets that have to get a high priority they don’t see it. a lot of ticket we receive concerns for more than one user and that means that only one person wil see this as a regulair mail with correct priority because they ar een the To field. in other helpdesk systems we have the option to add extra To users so we wil ask if there could be an option for that?