server email limit

Hi all.
I host www.newmediafilmfestival.com site at Holistic Solutions. They have a server limitation of sending only 250 emails per hour, via cron. Could someone please tell me how to overcome this limitation? Our mailing list is huge, so the sending of it would need to be broken up somehow into batches of 250. Is this possible? Is there a better solution?
Thanks in advance.
Dima