Default for sending out email is always the same* which you cannot change it. What you can change is reply-to email address of your own for customers, different than regular company email address.
- *default email address from Intuit[email@example.com]
From the home page screen > company gear (upper right corner) > settings > company > contact info > add customer email (this is where you add email different from the company email address).
[table id=12 /]