help regarding possible scam

[KarrarDarraji]

Hello,

So i am selling a laptop and someone approached me with this

so apparently he sent me cash through paypal, and i couldnt find it ONLY in Spam emails, stating his name and the amount, when i went over to paypal account there is no transactions whatsoever, when i asked him he said paypal would not give me the money only until i send the laptop through post office, and the post office would give me an EMS number starting with the letter E ad then after i send it, i will reforward the EMS number and paypal will see it and send me the money.

Is there such a thing? 

Please let me know, as i have to make the shipment