A couple of months ago MS decided that our registration emails going to hotmail accounts were spam and would not deliver them. The registration agreement was changed. New members were asked to use a yahoo or gmail account to avoid this problem in case MS decides to not deliver our registration emails again.
Thanks, Texstar, for the explanation !
I looked before posting this and the notice to not use Hotmail is still listed on the registration page.
I know that it is probably not quite acceptable but I did get them registered using my e-mail addy.