I am selling an item to someone which requires me to ship the item. I got an email saying I have a payment, but I won’t be able to get the money for 7 days. The guy I’m selling to is saying that when I ship it, and give him the tracking number, he can release the funds to me. He paid via goods and services. Is this a real transaction protocol? I also have searched the transaction number in my account and it says that the transaction was unable to be found.