There are many Email Marketing programs to choose from. Here are a few that I have either used myself, or I know people who have had positive experiences with them.
AWeber is an email marketing service provider with over 100,000 small business clients world wide. We help people keep in touch with the subscribers who have requested to be on their mailing list.
Regardless of industry or business size, AWeber helps our customers keep in touch with with their subscribers, all while upholding email marketing best practices.