Well, clearing the notify table did not help. This is strange though. I went into the classifieds admin panel and changed the notifications from email to messaging. I don't really understand what they does because the notifications are still sent by email. But, that did away with the bounced email messages. It seems to have created a new problem though. I am using VBulletins RSS tool to post new ad notifications to a specific forum. After I changed the notifications to messaging, I now get double posts in the forum for each ad that is placed.