Problem with LISTSERV authentication

[Alessandro Raolil]

Hi all,
i have correctly join gradsusr mailing list, i've received confirm mail
and i've activate my LISTSERV "account"; i can send and receive mail
to/from "GRADSUSR at LIST.CINECA.IT" but i cannot access online maling list
archives. I try to log in with this mail address
"alessandro.raolil at le.isac.cnr.it", but i obtain in response

"Not authorized
Sorry, you are not authorized to browse the archives of the GRADSUSR list
from the address you entered in the login screen."

Can someone help me?
Thanks
Alessandro