You should have checked your Paypal account first before sending the item. Emails can easily be spoofed/faked. Try checking the headers of the email messages you received to see if they're really from eBay and Paypal.

You have been ripped off! You received a bogus email from the person that you sold your item to! He sent you a bogus eBay email and a bogus receipt from PayPal take a look at your PayPal receipt it says Dear PayPal user doesn't it? And when you went to your actual PayPal account there's no money in it is there?

You were scammed! And there's nothing you can do about it both PayPal and eBay specifically warns about this kind of scam never ever ship your item never ever under any circumstance until you look in your PayPal account by yourself and see the money posted! If you act quickly and call eBay security they may be able to send an officer to stake out the address that you mailed it to and arrest this scammer but don't count on it but it's worth a try

It is probably in the pending payment section. PP won't release the funds into your account until they have been cleared from the buyer account

Never ship the items first!!

Make sure the email you got from eBay and Paypal are genuine, hover the mouse over the senders email address.

Log into your paypal account, transaction history should have the payments, if genuine, logged there.

If the payments where with an eCheque, these can take a few days to clear.

If there is no sign of any payments, call up eBay's customer support number.

Fake ebay and paypal emails are very common, especially for new sellers/buyers and expensive items.

You might have been scammed, so get onto it now, if you have been scammed you may be able to get your stuff back by calling up the company you used to post and getting it stopped.

Email the contact for PayPal (bottom of the screen) about this.