Reported for spam abuse


I got an email from the abuse department telling me there was spam abuse reported against me.
We regret that it has become necessary to issue this Policy Enforcement Notice for violation of our AUP or TOS available at and based on complaints and/or logs of abuse attached or included below. We will review the complaints and/or logs again if you believe this is an error. However, it is your responsibility to investigate your account and reply promptly to avoid disconnection. You are required to suspend or remove all domains, sites, users, and/or exploits causing this issue.

Pending your reply with your comments, questions, or actions to resolve this issue, the account is:
[ ] Monitored for Additional Violations
[ ] Accessed for Investigation, Cleaning, Hardening, or Securing
[ ] Traffic filter applied
... [ ] Outgoing traffic: none
... [ ] Incoming traffic: none
[x] Suspended in:
... [ ] 48-Hours
... [x] 24-Hours
... [ ] 12-Hours
... [ ] 6-Hours
... [ ] 1-Hour
... [ ] 0-Hours
It goes on to show a copy of the original complaint and contents of an email apparently sent through my server. But it wasn't me. There are 5 domains associated with the email:,,, and - none of them mine. The email is trying to impersonate an site selling MobileMe.

I submitted a support ticket (#47487) and also replied to the KnownHost abuse department sender (Helen), but haven't heard back.

What can one do to prevent their email server from being used by spammers? I understand the urgency in putting a stop to this activity, but will my server be shut down, or is there a solution to the problem that will prevent the members of my forum and other sites from being inconvenienced?