Hi
normally you can only be an open relay if you are accepting incoming mail and forwarding it. These blacklist sites typically employ a probing technique to see if they can get a mail relayed through you.
So, if you aren't running any SMTP server (it's disabled right?) it's hard to see how you could be an open relay.
Have you had your IP long? It could be a hangover from a previous owner of the IP if you acquired it recently.
Also, if you have something like an open SOCKS server or HTTP proxy that accepts CONNECT commands, then you could be used by spammers to send through - i.e. if they bounced off you.
You would see evidence of this in your proxy logs, normally WinGate won't bind to the external interface for services like this.
So, things to check.
1. Check the SMTP server is actually disabled
2. Check that there is no firewall hole open on port 25 for Incoming connections from the Internet
3. Check your HTTP proxy is not accepting connections on your external interface (if you were using it to pipe connections into your LAN, you may need to lock it down).
4. Check the SOCKS service to make sure it isn't available from outside your LAN.
You could do a quick port scan on your network by going to
www.grc.com if you like, it will tell you if you have any of these ports open.
Once you have verified you are locked down, you can typically request a re-test from the blacklist site to get you off their list.
Regards
Adrien