In most cases email servers will use the same server for sending and recieving, although this is not always the case.
You have not mentioned if this is a personal emai account(s) ... or maybe I missed it.
Anyway for your personal reference the "administrator" that is sending you the notification is not a real person. That is the email server letting you know that there was a problem with the email transmission and that you have a problem - could be a problem with your configuration or a problem with the server.
We really need to see the message tht you are recieving in order to help any further
