iPhone Alert When Silent

So I have a surveillance system which sends me email alerts when it detects activity. I have already added it to my VIP list so it has a special alert sound. Now I want it to give me that alert even when the phone is silent. Anyone know how to do this? I've searched a bunch and haven't found any app or anything.

I want an app like this for example,
http://appworld.blackberry.com/webst...countrycode=US