Here is the list of the most popular companies that provide email autoresponder tools - the programs that send a pre-written reply to anyone sending a message to the autoresponders e-mail address.
Get Response - is an easy, web-based email marketing software that delivers your campaigns, offers, newsletters, follow-ups and autoresponder messages. GetResponse provides you with unlimited email marketing campaigns, autoresponders, follow-ups, lists and broadcasts. You can choose from more than 150+ professionally designed HTML templates. You can include graphics, spreadsheets, Word or PDF Document, audio and video. GetResponce allows you to choose the language of the message.
Aweber - is a tool to capture visitor sign ups, send unlimited follow ups and newsletters, increasing your profits. Unlimited campaigns, lists, follow up messages, and newsletters. It has HTML creator and /or plain text message capability, a web form generator, a wide range of HTML email templates that allow larger fonts, bold, colors, and images. Easy web form generator allows easy addition of opt-in forms to your website, pop-ups, pop-overs, hover pops, and exit pops along with split testing of different forms.