Autoresponder for free  

I run a website and collect email addresses from different websites and forums in order to do marketing of my products. So in other words, i maintain a huge email list of my own.

I am looking for a tool or a software that can maintain email list for me so that i can send email to all the emails at once rather than using free emails for this purpose and send limited number of email per day.

Some tool that will sort out duplicate addresses and extract email from other email applications as well.

your help will be highly appreciated.

I’m looking for an autoresponder service that’s inexpensive, but will allow me to send out several prewritten emails on a scheduled basis as is commonly done for email marketing. For example, sometimes you can sign up for a 5-day email course to teach you how to do something. That’s what I’m interested in. Also, could it be set for weekly instead of daily delivery? Could I have multiple courses available? That’s what I really want.