This sounds like an awesome idea, and a product I'd definitely use. Just a tip though - I had to read halfway down the page just to find out what nvlope.com IS

This sounds like an awesome idea, and a product I'd definitely use. Just a tip though - I had to read halfway down the page just to find out what nvlope.com IS (an email client with an API). "It's time to move email forward." is a nice sentiment, but it really doesn't explain your product at all. You should think about adding a short descriptive tagline that actually explains it before listing out a raft of features.