In linux.debian.user, you wrote:
Hi there Got this from my ISP the other day:
We have been forced to take your server off line, since your server is
performing phishing from your secondary IP address xxx.xxx.xxx.224.
That IP address was one [of] my secondary IP's, using Debian Sarge,
have iptables firewall, using qmail as the mail server ..
"aptitude install exim4" should get rid of that insecure piece of !@#$
qmail for you. Alternatives include Postfix, ssmtp, and even
Sendmail among others. "aptitude search smtp"
Google "qmail phish"