how to stop people using mail.mydomain.com to send spam ?

[txn]

Hi guys,

I find out that I can easily send out email by using mail.mydomain.com to any email without verification.

How do i make it to verify the user and password before allow to send out ? I'd like to have some sort of user authentication for smtp server.

Thanks
________
HONDA CB250

 

[nobaloney]

You do. Unless you've edited and broken exim.conf, your server won't relay email from unauthenticated senders; it authenticates either by password or by popb4smtp.

Just check to make sure you haven't included any any domains or email addresses on your server in any of the /etc/virtual/whitelist* files, because they'll open holes and enable senders who know to spoof these and relay through your server.

The real problem is usually that people sending from other places can spoof your from address; there's no way to stop that.

Jeff