Mail being sent from my domain...

[Rob W.]

I hope I'm in the right area and someone could possibly help me with this.

I am running FreeBSD 5.4. I installed qmail from www.qmailrocks.org

Everything is working correctly and I do have spamassassin and clamav installed and working.

Lately I have been getting emails back saying that someone is sending mail out from xyz at mydomain.com. If anybody can help. I do have the patch installed so that open relay is disabled and a user needs an account on the qmail system. I have been watching the email accounts and it has not been breached as far as security.

Is it possible for people to send email out from my domain name and have fake users acting as comming from my network? If so, is there anything I can do stop this or prevent it?

Thanks.