Any suggested patterns for building an Email Client System with Voice Recognition Support?

Wow, that's a tall order.

You definately need to be more specific.

Mike

Since the question is at a very broad level, and not targeting any direct issues, you may start with based on your UI requirement
with 
- MVP
- MVC
- MVVM
for your UI architecture followed by appropriate design principles or patterns as required.

Do you have any specific issue in mind, that you are looking our for targeting with patterns?

In any case the above UI patternn will give you a good structure to your application irrespective of the patterns and principles your are using at the bottom and middle layer.