postmaster gets false mails

[Matus Uhlar <uhlar@ccduck.ke.sanet.sk>]

Hello,

some mailers included address "uhla@ccnews.ke.sanet.sk" to their lists, and
I now get much such mail...
can I prevent it ? why should I as postmaster get e-mail when someone is
using false adresses on my machine from outside ?

I run 2.97
-- 
 Matus "fantomas" Uhlar, sysadmin of one server at SANET Kosice, Slovakia
 E-mail: Matus.Uhlar@tuke.sk ; WWW: http://ccsun.tuke.sk/users/uhlar
 And don't forget: I work for SANET, but talk for myself, dude... ;-)