“Your auto-responders need not be fancy or particularly creative…thank your reader/visitor for whatever they did that triggered the autoresponder, give them something else to consider that is relevant to their demonstrated area of interest, and provide your contact information in case they have any questions. That’s it.”
Don’t go overboard with thank you emails, as short, sweet, and to-the-point emails work just as well. This doesn’t mean you should neglect your email design, rather that there’s no need to load emails with lots of digital bells and whistles. Just say thank you, whether it’s for subscribing, staying a loyal customer, etc.