We have created an App for product sellers to create, manage & measure the end-end Customer eXperience. The first step of which is to ask for a seller rating. We used buyer-seller messaging API to request a feedback from the buyer using the buyers alias marketplace email ID. My email service provider shows the message is delivered to Amazon. But my test customer has not received anything. We see vendors like Feedback Genius aka Seller Labs are able to do it. What should we do to get that entitlement?