How to setup mail to limit 450 msgs per hr

Hi,
If I wanted to create a campaign with a big list of subscribers, but wanted to limit only sending the same email to 450 per hour, how do I do this and to make sure the program will only send once to each person on that list?
Thanks,

If I wanted to create a campaign with a big list of subscribers, but wanted to limit only sending the same email to 450 per hour, how do I do this and to make sure the program will only send once to each person on that list?
Thanks,
