GetResponse
GetResponse (http://www.getresponse.com/) is an autoresponder. I have used it to set up tech tips to be emailed on a predefined (by me) schedule to those who request to receive them. On the current home page, click on Pricing and choose Free to set up a free account. Works fine with no limitations or expiration, but the messages include some advertising. None were ever found objectionable when I used it at school.