Autoresponders are extraordinary! They can be used for a variety of things, but there are several ways that autoresponders should not be used. Using autoresponders in improper ways will make things a bit more difficult for other people, & it could make things really bad for you!
Having one autoresponder respond to another autoresponder creates chaos, and in some cases, it can overload servers. This happens when you sign up for something, using your autoresponder email address. You sign up, and a message is sent to someone else's autoresponder, which responds to your autoresponder, which responds to that autoresponder - and this continues on and on until it is manually stopped and straightened out.
Some people use their autoresponder address on purpose when they sign up for discussion lists. In effect, this causes an their autoresponder message to be sent to the entire list, or to one person on the list, each time a person sends a real message to the discussion list. Needless to say, discussion list members and owners frown on this practice, and the autoresponder owner gets banned.
Avoid these problems and use your autoresponder in ways that it was meant to be used. Do not use the autoresponder irresponsibly! Not only will you create problems for others, but you may find that you get reported for spam!