Sending out "throttled" bulk emails?

I’m running a campus-wide game at my school (UMass Amherst), and I need to send out emails to all the players (around 1200). I worked with DreamHost to get my email limit upped from 100/hr to 500/hr, but this is still not enough.

They suggested to me that I throttle the emails that are sent out, running a cron job every hour to send out the next 450 emails in the queue. Does anyone have any experience with this? I’ve done some research on email queues and found stuff about mqueue, but I’m very confused on the topic.