aliases issue !!!

[nissim_p]

Hello all ,   I still didn't get an answer for my question about aliases defined in /etc/aliases regarding their vulnrabilty to outside world .   I am not intersted in letting people use certain aliases in /etc/aliases from the outside and maby even restrict the access to these aliases to certain users only .   How can I do cause now  everyone can use these aliases like [EMAIL PROTECTED] which is a spam hole .   Thanks , Nissim .