Sellers have to rely on the buyer to leave feedback, or to make contact (if something is wrong) in order for them to be sure that the item has been received.

I tend to think along the lines of ...no news is good news 🙂

As a buyer I dont always leave feedback. But I do sometimes email them to say item has arrived. 

As a seller, i just wait and see if they leave feedback, if not, then i dont worry too much about it.

🙂