Sending Mass Emails

I have a massive list of users who registered for accounts and opted into a mailing list on my web site and I am interested in sending out a weekly newsletter. How should I go about doing this. I tried sending it out through my host server, but I received a notice stating that if I did it again they would kick me off the server. Are there any good companies that are designed for this type of thing? I need to find a company that will support this and show me some sort of report about how many emails get opened, deleted, opened then deleted, etc. Any recommendations?

See original post by mike1179