Email Error Message Keeps Hitting Inbox

Even though I have successfully received email from this address, I am getting an email error message that keeps hitting my comcast.net Inbox (5-10 times and counting): "This is an automatically generated Delivery Status Notification. Delivery to the following recipients was aborted after 49.2 hour(s): * HIDDEN PERSONAL NAME@********-il.gov Reason: Temporary Failure"  What can be done to stop getting this error?