MetroMail - Mail UI

MetroMail Series:


Edit #1: I've added a contacts UI, which is available via this [link]

Edit #2: Added background to UI, different desktop background

Edit #3: Changed icons of multiple buttons on bottom, adjusted colors

Continuing on this concept, I've added some simple elements to the UI, as well as rebuilt the base to get a better idea of how it would be laid out.

The next group of refinements will likely be to improve the buttons on the bottom, refine the navigation, and maybe reconsider if more color should be added. Also, there should be an edition with the other conceptual elements shown.

This is all concept, and I'm not a programmer, but any thoughts on how this could be improved?

The following are links to the other parts of this concept:
Calendar | Contacts | Mail