The typical process for enabling a seller to respond to questions from prospective bidders is:

  1. Your application lists an item for sale. The ItemID is returned from the listing.
  2. A buyer uses the eBay marketplace to ask the seller a question about the listed item. The MessageType for this message is internally set to AskSellerQuestion.
  3. eBay stores the message, marking it as Unread.
  4. Your application checks Item.ListingDetails.HasUnansweredQuestions and Item.ListingDetails.HasPublicMessages for the ItemID.
  5. Your application calls GetMemberMessages to retrieve the MessageIDs of any unanswered messages for the ItemID.
  6. If there are messages, your application retrieves the MessageID so it can respond to the buyer by posting a message to the marketplace.
  7. Your application calls AddMemberMessageRTQ, providing the option to the seller of whether to post the question and the seller's response for all to see, and whether to send a copy of the email to the seller's personal email address.