If you're not getting your order notifications about online orders processed through PayPal, you will want to check your account settings in your PayPal account to make sure it is configured properly.
Sometimes PayPal will pop up an ad after you log in. If they do, you can click My PayPal at the top to go into your account and bypass the ad. Here are the steps to follow to check your settings for Instant Payment Notification:
1) After logging into your PayPal account, click Profile in the upper right.
2) In your Profile, on the left, click on My Selling Tools.
3) On the right side, go down to the second section of tools, 'Getting paid and managing my risk', and find the Instant Payment Notifications. Click the Update link.
4) Your IPN should be ON by default, if it is not, click the button (1) to turn it on. Most likely it appears as below. If so, do NOT click to turn it off.
5) You will want to configure your settings for IPN, so click the Edit Settings button.
6) To configure your IPN settings, put your own domain in the Notification URL field, and make sure the IPN Messages is set to Receive IPN Messages (Enabled). If you made any changes, be sure to click Save.