I completely understand where you're coming from. I would probably use it this way if it was possible. I just honestly believe that the vtext site wasn't designed with that concept in mind. The reason i say this is because there are many options out there to access email on your device. I really believe that the furthest extent of vtext is purely just to text another person if your phone isnt on hand, or you want to text an easier way then on the phone.

This was taken from the vtext website:

• Text to another mobile phone - using any 10 digit phone number that can receive a text message.
• Text to a mobile phone from your PC using the "Send a Text" option from the menu at left.
• Text to mobile phone from E-mail, send and receive text messages from any email address in the world by addressing the email to your 10 digit mobile number, number@vtext.com, or your custom nickname@vtext.com.