I would like to have the feature to send my emails selectively to my members

I have a social community site with about 35,000 users. From time to time I would like to send all my members email updates and news. My problem is that my provider only accepts 1000 emails per day. So I would like to have the feature to send emails selectively. I want to get the feature coded in the site admin panel so I can manage my emails. I would like to have each page sorted with 500 members (email addresses) with the option to send to all (500 each page) or individually. Thank you, Teddy