help w/ a scammer

[t-maxxracer32]

hey recently i sold something to a guy in canada and when i shipped it out (over a week ago) i didnt get a tracking number or anything since it was first class and i didnt keep the receipt (stupid of me) and now the guy is complainigng to paypal about not getting the item.

i cannot provide a tracking number and i have no proof of it being shipped. im going to the post office to ask if they keep records but if not what do i do?

thanks