I can open a ticket by sending an email, I can respond to tickets and they land in the customers email, and everything works perfectly. The problem is that almost everyday my ticket system is getting 300+ failure notices out of no where. My admin mail box gets filled, there are 300+ tickets open that says failure notice, and I do not know how to fix this. I use piping and it works great but I still get these failure notices. I used osticket in the past on a different server about 1 year ago and used to get the same problem.
I have attached two screen shots. Can someone please help?

