On Plesk 6.5.2 if some one send wrong message (with wrong address ) return MailEnable: Message delivery has been delayed. Message is waiting at [our server].[our company].net for delivery to jsjjsjjsjsjsjs.com Reason: Mail Server for jsjjsjjsjsjsjs.com could not be contacted at this time. MailEnable will keep trying to deliver this message and will notify you of any progress. instead generate a "MailEnable: Message Delivery Failure." and delete message from queue . I check DNS ( It's OK ) , MailEnable Config ( It's ok ) . Any body can help me or any Idea .