Qmail RCPTHOSTS/SPAM

[mleck]

Okay,

I have a question: I am running qmail, with vpopmail, and courier-imap. I have it all setup, and it's working great. One problem... it seems that on my 15 computer network, there is a virus of some sorts, and it is sending a ton of outbound emails. However, because of my firewall, it will only allow it to connect to specific outbound mail servers on port 25 (my own), and it requires that you authenticate with the outbound mail server to send emails to someone@anotherhost.com. However, it does NOT require you to authenticate if you are trying to send emails to someone@myhost.com. So, it seems like it has figured this out... and we are getting a ton of junk mail send directly to *@myhost.

I was able to confirm that it was sending through our server by checking qmails outbound email queue. How do I make it mandatory for people to send email to authenticate? Regardless of weather it's to someone at one of the localhosts or some other host? (IE - No trusted server... you have to authenticate to send to everyone)