H,
A m8 of mine is running a mail server ! but we found some one coming onto server and using it to spam other ppl wot we cant fig out is how he's doing it, he hasen't got an account and to get on he would need a userid and password which he dont use; he just relay's through us and we want to know how to stop him his ip is world wide address so we cant find his isp!
any ideas ? server proggy is called argo.
TIA