Configuring autoreply on server side

Last week One of my user whenever he receives email internally, he send out outo reply message which has name change subject. I have checked the client, he did not set any rules. WE thought it must have set on server with script. We tried to trace the message it shows the message came from system attendant. Please let me know how to turn off that message or where the script is located.
thank you
abyanfiat