I am using sandbox mode.
I click buy item on my shop, and after i pay with sanndbox account it takes me to "Thank you for your payment - Paypal" but doesn't redirect back to my site! I already have IPN setup!
I dont understand, do I need to contact paypal first ? or is there some section on paypal where you can enter your shopping site URL to get it authorized ?
good comparison of the various methods here: https://www.x.com/message/108223#108223
when using IPN, the transaction information will be posted to your ipn handler url directly from paypal in the background. the ipn url can be specified with the "notify_url" parameter or in your profile.
the customer will be redirected back to your site. the target url can be set in your profile or specified in the transaction using the "return" parameter.
IPN sends the notification to your server behind the scenes, whether the end user is redirected or not.
PDT, is a different (though somewhat similar) technology offered by PayPal, which sends the data when it redirects. Are you sure you are not receiving IPN notifications?