I agree, E2V is a great idea. If you can find a way to simplify the setup, I have about 6 friends who would want to use it.

Could you pick the most popular email app (Gmail? Yahoo?) and find a way to simplify the setup for just that app? Or build a plugin or browser extension to make it super simply to setup? I'm thinking a little phone icon on each row in gmail, you click on it and a box pops up and says "Hey, want to get a call when you receive emails like this?" They click Yes and boom it's setup.