Placing An Order With Unknown Distributor
Orders placed with products not properly assigned with a distributor will receive a New Order email with a message.
One Order:

Multiple Orders:

The message will state that the order can't be sent because a distributor is not assigned and then list the products.
Identify Unknown Distributor

SmartOrders > Inventory Button can help pinpoint products without Distributors by selecting Unknown Distributor from the Disitrbutor dropdown.
When viewing product details, use the distributor dropdown to designate the correct distributor.