i'm a hostgator reseller, and i don't see why you would not be able to discuss the situation with the techies there... did you ever asked at least... they could promote your account to a higher level if you really need to send that much of emails regularly...
here are the actual policy for the emails on HG:
http://www.hostgator.com/mailpolicy.shtml
btw, why would you need to send 9000 emails in a single shot... you want to spam all your members with communiqu?s ?!... just make an announcement on your forum.