Why aren't my fulfillment notifications and emails being sent to the warehouse?
When using one of our integrated fulfillment or custom fulfillment options, notifications are only sent to the warehouse after marking the items fulfilled on the order in your Shopify admin. The warehouse will not receive notification until that step is completed.
Fulfillment by Amazon
You might see this error message when trying to fulfill with Amazon:
The request must contain the parameter PerUnitDeclaredValue
This error message is returned if you try to send a shipment to an APO (Army Post Office) address. Currently Amazon does not support fulfilling to overseas army bases.