Thanks @achim03, my suggestion was not to take $18 from their own pocket but earn that on the Steem blockchain and invest in an autoresponder and then use affiliate marketing to have it pay for itself and make a profit, but as you said that also takes time.

If you really want an autoresponder for free and be able to use affiliate links then freefollowup might be good, the drawback is that they serve ads, that is how it's free, and there is only one list per account, but you are allowed to have as many accounts as you want, there is also unlimited amounts of emails and unlimited subscribers, but as I said they serve ads on their site and in all outgoing emails.