Auto-Responder

Hi.
I will have my website up soon, and I thought it would also be nice to have a bi-monthly e-mail sent out to my customers with tips etc.
1) Can you recommend an auto responder that will do all the subscribing, unscribing and sending out the e-mails automatically.
2) I am looking for an inexpensive program here, but something that actually works……

Thank you…..Pat