Jim,
I'm assuming you're running an Exchange Server as the Backend to your Outlook clients. If true, there is a way to configure it to modify these actions. There is a restricted Public Folder under All Public Folder named Outlook Security Settings and there should be one message in there. The Exchange Administrator can use this to configure different settings as defaults or for an exception group. Check out the "Programmatic Settings" tab and note that the defaults are all "Prompt User".

Note: I just learned about this and HAVEN'T actually tried to use this for anything yet.

Rick