Yes, apparently, it's a bad idea.Do you mean that you can't have a nameserver which has both an A record and an AAAA record assigned to it?
Do you have any links to this? I'm concerned because our only provider offering us tunnelling (which we'll all need as we begin to offer IPv6) is HE.Another ISP that had problems is Hurricane Electric, but they are a tunnel broker, so maybe they got confused as well.
I notice this now; the entire postmaster.hotmail.com site is gone .Regarding contacting Hotmail, there doesn't seem to be an easy way. I only found one form that deals with email blocking when sending to hotmail, but we didn't have that problem, we could send to everybody.