[exim] spam before list

Today at 1130 i activated (but did not advertised,neither added any
user or sent any message) a list for local users.
at 2330 arrived the first spam message ....
:-(((((((((((((

--
Leonardo Boselli
Nucleo Informatico e Telematico del Dipartimento Ingegneria Civile
Universita` di Firenze , V. S. Marta 3 - I-50139 Firenze
tel +39 0554796431 cell +39 3488605348 fax +39 055495333
http://www.dicea.unifi.it/~leo