automatically buyer cart cases considered day digital disable enabled entered goods google-checkout item manually marked notification option order sale send sending ship shipped shipping tangible zipcode

Google Checkout is automatically sending shipping notification to the buyer of tangible goods? How can I disable that? Sometimes I cannot send the item on the same day. So I want to send Google Checkout shipping notification manually on the time when I ship the item.

Order is considered a digital order and marked as shipped only if there is no zipcode entered by the buyer and that can only happen in two cases:
1. Either you are not using our cart.
2. The shipping option was enabled at the time of the sale.