I emailed the developer to ask some very specific questions concerning how this product works. This is the response I received;

On Oct 23, 2008, at 6:09 AM, Big Key Mail Support wrote:

there are several features. the nest is that you try the app. The sdk permits things that we are not even aware.. You can see some details about the features here: www.bigkeymail.com

This may be the greatest program of its kind for iPhone and iPod Touch. I however, will never know.