Trap mails reporting delivery failure in mail-in-db

Hi,I have created mail-in db which is recieving mails and after some peocessing, mails are sent from the mail-in-db to the specific senders.I have set the deliveryreport=“B” field in this outgoing mails so that it informs the sender about failure.But if I want to get this delivery-failure mails into mail-in-db then how can I do it?Someone plz help!