Hi Brandy,
AFAIK, Outlook cannot take action as soon as you assign a category. However, you can use a feature in Outlook 2010 (or higher) called Quick Steps. These are similar to Outlook Rules and Alerts, but they can only be invoked by you clicking the appropriate Quick Text Hotkey button.
In your case, you could assign one Quick Step to be the rejection pile, and one for the accept pile. Assign each the appropriate category, then Reply using a template (which you fill out). Once the two Quick Steps are saved, just invoke the one you need when you accept/reject the person.
It's not quite automatic but its much closer.
Hope this helps!
Mike Sperry
http://www.SperrySoftware.com
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