Ever wonder why you get these emails? It may be that you were sent spam that we rejected and bounced back to the sender. However sender was either fake or the sending network also thinks it spam and will not accept delivery. Either way the email can not be delivered. Free e-mail providers often allow spam to be sent from their network and then call it spam when you send it back to them. That's when they realize it's spam. The server is merely confirming conclusion it was spam. You may ignore and delete these notices.

On the other hand if you get this message regarding an email you actually sent do not ignore that notification. Instead see the text immediately following "A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed:" The reason for failure could be misspelled recipient or perhaps they were over quota. If the reason stated are anything other than these two scenarios please open a support ticket or forward email to Tech Support.