I think you may find that AT&T and a few others are using third party RBL databases - without cause. The RBL "
JustSpam" has your IP listed in both their MX and Website IP addresses, just as an FYI...
You can check here to confirm:
http://www.justspam.org/check-an-ip?ip=65.44.220.57
Hope this helps - and having run websites since 1998 - I used to pull my hair out on issues like this... Now? I'm going bald so no hair left to pull
John