You can review any delivery you've made/attempted in the Connections - Previous Deliveries area.
Click 'Show Releases' by each batch and each delivery will have a 'Status' tag of one of the below:
Failed - Delivery has failed to generate due to an error
Pending - Delivery is in progress/queued or has timed out
Missing Data - Delivery was blocked due to the minimum requirements of the end point not being met
Delivered - Delivery has been made and has registered as present with the end point