Dear all!, We've made mail filter rules to reject unknown recipient. We solve this by giving a low priority rule in Mail Filter that will block it not accepted mails. This also works, but block is not good! If we block email, the sender is not notified. If we make "Notification" action object, the sender will receive a new letter! This is not god!, if sender use false email address, we send a notification email "SPAM". is it possible to use reject rule somehow ? I just found only a block action in available objects.