Jet.com requires the acknowledgement of orders that are awarded to sellers within 15 minutes of the order being placed.
ShipStation does this automatically on your behalf by running the order import process for your Jet.com connected store once every 15 minutes. (Note: this is a unique feature to ShipStation's Jet.com integration)
ShipStation acknowledges and imports the orders if you have available stock for the order items within your ShipStation Inventory Warehouse(s) that are linked to your Jet.com Fulfillment Node(s).
If you do not have available stock for the order in your ShipStation Inventory Warehouse, ShipStation will acknowledge and reject the order and it will be awarded to a different Jet.com seller.