I use and love Aweber too. There`s also Email Aces, GetResponse, 1ShoppingCart, ConstantContact, etc. There are lots of autoresponders - choose one that fits your needs.
Just a word of caution. There are free autoresponders out there, but you do get what you pay for. And if you are unhappy with the service, it can be a pain in the neck to switch everyone over to a new autoresponder. Good luck!
Health & Prosperity,