Ok, i set up a ISS Email server on iis6, then a hour after, some taiwans begun spamming mails from my server, how do i make it so they cant? i tried selecting basic authentication, but that require that the email user have an account on the server... how do i set so people can login with their email...

I have recently found a rootkit on my computer through AVG and am wondering how to get this thing off. I tried to get AVG to delete it but it said it cannot. I heard you can re-install windows vista and also restore default settings but I am not sure if that deletes everything and I'll have to get...