You must choose server for mailing/newsletter (I guess it will be VPS) from the market then install newsletter script (you must choose the best newsletter scirpt) then finally configure everything.
Our database has 700k emails. Everything must be configured right so that we will be not blocked.
Newsletter must have all type of statistics like how may percent opened email, option we can resend again to those people who not opened email.
Follow up, we write emails then when somebody signsup got all our prospects. Of course subscribe and unsubscribe links.
Looking for the offers.